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SIPPING J. Van Dyke Internet-Draft E. Burger, Ed. Expires:September 1,November 27, 2006A. Spitzer BrooktroutCantata Technology, Inc.February 28,A. Spitzer Pingtel Corporation May 26, 2006 Media Server Control Markup Language (MSCML) and Protocoldraft-vandyke-mscml-07draft-vandyke-mscml-08 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire onSeptember 1,November 27, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract Media Server Control Markup Language (MSCML) is a markup language used in conjunction with SIP to provide advanced conferencing and interactive voice response (IVR) functions. MSCML presents an application-level control model, as opposed to device-level control models. One use of this protocol is for communications between a conference focus and mixer in the IETF SIP Conferencing Framework. Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page 1] Internet-Draft MSCMLFebruaryMay 2006 Intellectual Property RightsBrooktroutCantata Technology, Inc. is making their intellectual property right interest in MSCML available on a royalty-free basis, per the terms described in the online IETF list of claimed rights at http://www.ietf.org/ietf/IPR/SNOWSHORE-draft-vandyke-mscml.txt. Conventions used in this document RFC2119 [1] provides the interpretations for the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" found in this document. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. MSCML Approach . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Use of SIP Request Methods . . . . . . . . . . . . . . . . . . 5 4. MSCML Design . . . . . . . . . . . . . . . . . . . . . . . . .76 4.1. Transaction Model . . . . . . . . . . . . . . . . . . . .76 4.2. XML Usage . . . . . . . . . . . . . . . . . . . . . . . . 8 4.2.1. MSCML Time Values . . . . . . . . . . . . . . . . . .98 5. Advanced Conferencing . . . . . . . . . . . . . . . . . . . .98 5.1. Conference Model . . . . . . . . . . . . . . . . . . . . .98 5.2. Configure Conference Request <configure_conference> . . .1110 5.3. Configure Leg Request <configure_leg> . . . . . . . . . .1311 5.4. Terminating a Conference . . . . . . . . . . . . . . . . .1413 5.5. Conference Manipulation . . . . . . . . . . . . . . . . .1513 5.6. Video Conferencing . . . . . . . . . . . . . . . . . . . .1714 5.7. Conference Events . . . . . . . . . . . . . . . . . . . .1715 5.8. Conferencing With Personalized Mixes . . . . . . . . . . .1816 5.8.1. MSCML Elements and Attributes for Personalized Mixes . . . . . . . . . . . . . . . . . . . . . . . .1917 5.8.2. Example Usage of Personalized Mixes . . . . . . . . .2018 6. Interactive Voice Response (IVR) . . . . . . . . . . . . . . .2520 6.1. Specifying Prompt Content . . . . . . . . . . . . . . . .2622 6.1.1. Use of the Prompt Element . . . . . . . . . . . . . .2622 6.2. Multimedia Processing for IVR . . . . . . . . . . . . . .3326 6.3. Playing Announcements <play> . . . . . . . . . . . . . . .3427 6.4. Prompt and Collect <playcollect> . . . . . . . . . . . . .3629 6.4.1. Control of Digit Buffering and Barge-in . . . . . . .3629 6.4.2. Mapping DTMF Keys to Special Functions . . . . . . . .3730 6.4.3. Collection Timers . . . . . . . . . . . . . . . . . .3931 6.4.4. Logging Caller DTMF Input . . . . . . . . . . . . . .4232 6.4.5. Specifying DTMF Grammars . . . . . . . . . . . . . . .4232 6.4.6. Playcollect Response . . . . . . . . . . . . . . . . .4433 6.4.7. PlaycollectExamplesExample . . . . . . . . . . . . . . . . .4433 Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page 2] Internet-Draft MSCMLFebruaryMay 2006 6.5. Prompt and Record <playrecord> . . . . . . . . . . . . . .4634 6.5.1. Prompt Phase . . . . . . . . . . . . . . . . . . . . .4634 6.5.2. Record Phase . . . . . . . . . . . . . . . . . . . . .4835 6.5.3. PlayrecordResponse . . . . . . . . . . . . . . . .Example .50 6.5.4. Playrecord Examples. . . . . . . . . . . . . . . . .5037 6.6. Stop Request <stop> . . . . . . . . . . . . . . . . . . .5137 7. Call Leg Events . . . . . . . . . . . . . . . . . . . . . . .5238 7.1. Keypress Events . . . . . . . . . . . . . . . . . . . . .5339 7.1.1. Keypress Subscription Examples . . . . . . . . . . . .5540 7.1.2. Keypress Notification Examples . . . . . . . . . . . .5741 7.2. Signal Events . . . . . . . . . . . . . . . . . . . . . .5942 7.2.1. Signal Event Examples . . . . . . . . . . . . . . . .6043 8. Managing Content <managecontent> . . . . . . . . . . . . . . .6243 8.1. ManagecontentAttributes . . . . . . . . . . . . . . . . . 62 8.2. ManagecontentExample . . . . . . . . . . . . . . . . . .6445 9. Fax Processing . . . . . . . . . . . . . . . . . . . . . . . .6545 9.1. Recording a Fax <faxrecord> . . . . . . . . . . . . . . .6545 9.2. Sending a Fax <faxplay> . . . . . . . . . . . . . . . . .6847 10. MSCML Response Attributes and Elements . . . . . . . . . . . .7050 10.1. Mechanism . . . . . . . . . . . . . . . . . . . . . . . .7050 10.2. Base <response> Attributes . . . . . . . . . . . . . . . .7050 10.3. Response Attributes and Elements for <configure_leg> . . .7151 10.4. Response Attributes and Elements for <play> . . . . . . .7251 10.4.1. Reporting Content Retrieval Errors . . . . . . . . . .7352 10.5. Response Attributes and Elements for <playcollect> . . . .7452 10.6. Response Attributes and Elements for <playrecord> . . . .7553 10.7. Response Attributes and Elements for <managecontent> . . .7754 10.8. Response Attributes and Elements for <faxplay> and <faxrecord> . . . . . . . . . . . . . . . . . . . . . . .7754 11. Change Summary . . . . . . . . . . . . . . . . . . . . . . . . 55 12. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . .79 11.1.55 12.1. Schema . . . . . . . . . . . . . . . . . . . . . . . . . .79 12.55 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . .90 12.1.67 13.1. IANA Registration of MIME media type application/mediaservercontrol+xml . . . . . . . . . . . .90 13.67 14. Security Considerations . . . . . . . . . . . . . . . . . . .91 14.67 15. References . . . . . . . . . . . . . . . . . . . . . . . . . .92 14.1.68 15.1. Normative References . . . . . . . . . . . . . . . . . . .92 14.2.68 15.2. Informative References . . . . . . . . . . . . . . . . . .9369 Appendix A. Regex Grammar Syntax . . . . . . . . . . . . . . . .9470 Appendix B. Contributors . . . . . . . . . . . . . . . . . . . .9571 Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . .9672 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .9773 Intellectual Property and Copyright Statements . . . . . . . . . .9874 Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page 3] Internet-Draft MSCMLFebruaryMay 2006 1. Introduction This document describes the Media Server Control Markup Language (MSCML) and its usage. It describes payloads that one can send to a Media Server using standard SIP INVITE and INFO methods and the capabilities these payloads implement. RFC 4240 [2] describes Media Server SIP URI formats. Prior to MSCML, there was not a standard way to deliver SIP-based enhanced conferencing. Basic SIP constructs, such as described in RFC 4240 [2], serves simple n-way conferencing well. The SIP URI provides a natural mechanism for identifying a specific SIP conference, while INVITE and BYE methods elegantly implement conference join and leave semantics. However, enhanced conferencing applications also require features such as sizing and resizing, in- conference IVR operations (e.g., recording and playing participant names to the full conference) and conference event reporting. MSCML payloads within standard SIP methods realize these features. The structure and approach of MSCML satisfy the requirements set out in conferencing-framework [10]. In particular, MSCML serves as the interface between the conference factory and a centralized conference mixer. In this case, a media server has the role of the conference mixer. There are two broad classes of MSCML functionality. The first class includes primitives for advanced conferencing such as conference configuration, participant leg manipulation, and conference event reporting. The second class comprises primitives for interactive voice response (IVR). These include collecting DTMF digits and playing and recording multimedia content. MSCML fills the need for IVR and conference control with requests and responses over a SIP transport. VoiceXML [11] fills the need for IVR with requests and responses over a HTTP transport. This enables developers to use whatever model fits their needs best. In general, a Media Server offers services to SIP UAC's such as Application Servers, Feature Servers, and Media Gateway Controllers. See the IPCC Reference Architecture [12] for definitions of these terms. It is unlikely, but not prohibited, for end user SIP UAC's to have a direct signaling relationship with a media server. The term "client" is used in this document to generically refer to an entity that interacts with the Media Server using SIP and MSCML. The Media Server fulfills the role of the Media Resource Function (MRF) in the IP Multimedia Subsystem (IMS) [13] as described by 3GPP. MSCML and RFC 4240 [2], upon which MSCML builds, are specifically Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page 4] Internet-Draft MSCMLFebruaryMay 2006 focused on the Mr interface which supports interactions between application logic and the MRF. This document describes a working framework and protocol with which there is considerable implementation experience. Application developers and service providers have created several MSCML-based services since the availability of the initial version in 2001. This experience is highly relevant to the ongoing work of the IETF, particularly the SIP [24], SIPPING [25], MMUSIC [26], and XCON [27] work groups, the IMS [28] work in 3GPP and the CCXML work in the Voice Browser Work Group of the W3C. 2. MSCML Approach It is critically important to emphasize that the goal of MSCML is to provide an application interface that follows the SIP, HTTP, and XML development paradigm to foster easier and more rapid application deployment. This goal is reflected in MSCML in two ways. First, the programming model is that of peer to peer rather than master-slave. Importantly, this allows the media server to be used simultaneously for multiple applications rather than being tied to a single point of control. It also enables standard SIP mechanisms to be used for media server location and load-balancing. Second, MSCML defines constructs and primitives that are meaningful at the application level to ensure that programmers are not distracted by unnecessary complexity. For example, the mixing resource operates on constructs such as conferences and call participants rather than directly on individual media streams. The MSCML paradigm is important to the developer community, in that developers and operators conceptually write applications about calls, conferences, and call legs. For the majority of developers and applications this approach significantly simplifies and speeds development. 3. Use of SIP Request Methods As mentioned above, MSCML payloads may be carried in either SIP INVITE or INFO requests. The initial INVITE, which creates an enhanced conference, MAY include an MSCML payload. A subsequent INVITE to the same Request-URI joins a participant leg to the conference. This INVITE MAY include an MSCML payload. The initial INVITE which establishes an IVR session MUST not include an MSCML payload. The client sends all mid-call MSCML payloads for Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page 5] Internet-Draft MSCMLFebruaryMay 2006 conferencing and IVR via SIP INFO requests. The media server transports MSCML responses in the final response to the SIP INVITE containing the matching MSCML request or in a SIP INFO message. The only allowable final response to a SIP INFO containing a message body is a 200 OK, per RFC 2976 [3]. Therefore, if the client sends the MSCML request via SIP INFO, the media server responds with the MSCML response in a separate INFO request. In general, these responses are asynchronous in nature and require a separate transaction due to timing considerations.There has been considerable debate on the use of theIn order to guarantee interoperability with this specification, as well as with SIPINFO method for any purpose. Our experience isUser Agents thatMSCML would not have been possible without it. At the time the first MSCML specification was published, the firstare unaware of MSCML, SIPEvent Notification draft had just been submitted as an individual submission. AtUACs thattime, there was no mechanism to link SUBSCRIBE/NOTIFY to an existing dialog. This prevented its use in MSCML since all events occurred in an INVITE established dialog. And while SUBSCRIBE/NOTIFY was well suited for reporting conference events its semantics seemed inappropriate for modifying a participant leg or conference setting where the only "event" was the success or failure of the request. Lastly, since SIP INFO was an established RFC, most SIP stack implementations supported it at that time. We had few if any interoperability issues as a result. As it turns out, using NOTIFY is not appropriate, as the NOTIFY would be in response to an implicit subscription. The SIP and SIPPING lists have discussed the dangers of implicit subscription. Using SUBSCRIBE is not appropriate for two reasons. The first is semantic. The purpose of SUBSCRIBE is to register interest in User Agent state. However, using SUBSCRIBE for MSCML results in the SUBSCRIBE modifying the User Agent state. The second reason SUBSCRIBE is not appropriate is because MSCML is inherently call- based. The association of a SIP dialog with a call leg means MSCML can be incredibly straightforward. For example, if one used SUBSCRIBE or other SIP method to send commands about some context, one must identify that context somehow. Relating commands to the SIP dialog they arrive on defines the context for free. Moreover, it is conceptually easy for the developer. In order to guarantee interoperability with this specification, as well as with SIP User Agents that are unaware of MSCML, SIP UACs that wishwish to use MSCML services MUST specify a service indicator which supports MSCML in the initial INVITE. RFC 4240 [2] defines the service indicator "conf" which MUST be used for MSCML conferencing applications. The service indicator "ivr" MUST be used for MSCMLVan Dyke, et al. Expires September 1, 2006 [Page 6] Internet-Draft MSCML February 2006applications that do not require mixing services. The media server MUST support moving the call between services through sending the media server a BYE on the existing dialog and establishing a new dialog with an INVITE to the desired service. Media servers SHOULD support moving between services without requiring modification of the previously established SDP parameters. This is achieved by sending a re-INVITE on the existing dialog with the Request-URI modified to specify the new service desired by the client. This eliminates the need for the client to send an INVITE to the caller or gateway to establish new SDP parameters. The media server, as a SIP UAS, MUST respond appropriately to an INVITE which contains an MSCML body. If MSCML is not supported the media server MUST generate a 415 final response and include a list of the supported content types in the response per RFC 3261 [4]. The media server MUST also advertise its support of MSCML in responses to OPTIONS requests, by including "application/mediaservercontrol+xml" as a supported content type in an Accept header. This alleviates the major issues with using INFO for the transport of application data, namely the User Agent's proper interpretation of what is, by design, an opaque message request. 4. MSCML Design 4.1. Transaction Model To avoid undue complexity MSCML establishes two rules regarding MSCML usage. The first is that only one MSCML body may be present in a SIP request. The second is that each MSCML body may contain only one Van Dyke, et al. Expires November 27, 2006 [Page 6] Internet-Draft MSCML May 2006 request or response. This greatly simplifies transaction management. MSCML syntax does provide for the unique identification of multiple requests in a single body part. However, this is not supported in this specification. Per the guidelines of RFC 3470 [14], MSCML bodies MUST be well formed and valid. MSCML is a direct request-response protocol. There are no provisional responses, only final responses. A request may, however, result in multiple notifications. For example, a request for active talker reports will result in a notification for each speaker set. This maps to the three major element trees for MSCML: <request>, <response>, and <notification>. Figure 1 shows a request body. Depending on the command, one can send the request in an INVITE or an INFO. Figure 2 shows a responseVan Dyke, et al. Expires September 1, 2006 [Page 7] Internet-Draft MSCML February 2006body. The SIP INFO method transports response bodies. Figure 3 shows a notification body. The SIP INFO method transports notifications. <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <request> ... request body ... </request> </MediaServerControl> Figure 1: MSCML Request Format <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <response> ...requestresponse body ... </response> </MediaServerControl> Figure 2: MSCML Response Format <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <notification> ... notification body ... </notification> </MediaServerControl> Van Dyke, et al. Expires November 27, 2006 [Page 7] Internet-Draft MSCML May 2006 Figure 3: MSCML Notification Format MSCML requests MAY include a client defined ID attribute for the purposes of matching requests and responses. The values used for these IDs need only be unique within the scope of the dialog in which the requests are issued. 4.2. XML Usage In the philosophy of XML as a text-based description language, and not a programming language, MSCML makes the choice of many attribute values for readability by a human. Thus many attributes that would often be "boolean" instead take "yes" or "no" values. For example, what does 'report="false"' or 'report="1"' mean? However, 'report="yes"' is clearer: I want a report. Some programmers prefer the precision of a boolean. To satisfy both styles, MSCML defines an XML type, "yesnoType", that takes on the values "yes" and "no" asVan Dyke, et al. Expires September 1, 2006 [Page 8] Internet-Draft MSCML February 2006well as "true", "false", "1", and "0". Many attributes in the MSCML schema have default values. In order to limit demands on the XML parser, MSCML applies these values at the protocol, not XML, level. The MSCML schema documents these defaults as XML annotations to the appropriate attribute. 4.2.1. MSCML Time Values For clarity, time values in MSCML are based on the time designations described in Cascading Style Sheets, level 2 (CSS2) Specification [15]. Their format consists of a number immediately followed by an optional time unit identifier of the form: ms: milliseconds (default) s: seconds If no time unit identifier is present the value MUST be interpreted to be in milliseconds. As extensions to [15] MSCML allows the string values "immediate" and "infinite" which have special meaning for certain timers. 5. Advanced Conferencing 5.1. Conference Model The advanced conferencing model is a star controller model, with both signaling and media directed to a central location. Figure 4 depicts a typical signaling relationship between end users' UAC's, a conference application server, and a media server. The document cc-conferencing [10] makes use of this model. The Van Dyke, et al. Expires November 27, 2006 [Page 8] Internet-Draft MSCML May 2006 application server is an instantiation of the conference focus. The Media Server is an instantiation of the media mixer. Note that user- level constructs, such as event notifications, are in the purview of the application server. This is why, for example, the Media Server sends active talker reports using MSCML notifications, while the application server would instead use the conference package [16] for individual notifications to SIP user agents. Note that we do not recommend the use of the conference package for media server to application server notifications because none of the filtering and membership information is available at the media server.Van Dyke, et al. Expires September 1, 2006 [Page 9] Internet-Draft MSCML February 2006+-------+ | UAC 1 |---\ Public URI +-------------+ +-------+ \ _____________| Application | / / | Server | Not shown: +-------+ / / +-------------+ RTP flows directly | UAC 2 |---/ / | Private between UAC's and +-------+ / | URI Media Server . / +--------------+ : / | | +-------+ / | Media Server | | UAC n |---/ | | +-------+ +--------------+ Figure 4: Conference Model Each UAC sends an INVITE to a Public Conference URI. Presumably, the client publishes this URI, or it is an ad hoc URI. In any event, the client generates a Private URI, following the rules specified by RFC 4240 [2]. That is, the URI is of the form: sip:conf=UniqueID@ms.example.net Where UniqueID is a unique conference identifier and ms.example.net is the host name or IP address of the media server. There is nothing to prevent the UAC's from contacting the media server directly. However, one would expect the owner of the media server to restrict who can use its resources. As for basic conferencing, described by RFC 4240 [2], the first INVITE to the media server with a UniqueID creates a conference. However, in advanced conferencing, the first INVITE MAY include a MSCML <configure_conference> payload rather than the SDP of a conference participant. The <configure_conference> payload conveys extended session parameters (e.g., number of participants) that SDP does not readily express but the media server must know to allocate the appropriate resources. When the conference is created by sending an INVITE containing a Van Dyke, et al. Expires November 27, 2006 [Page 9] Internet-Draft MSCML May 2006 MSCML <configure_conference> payload the resulting SIP dialog is termed the "Conference Control Leg." This leg has several useful properties. The lifetime of the conference is the same as that of its control leg. This ensures that the conference remains in existence even if all participant legs leave or have not yet arrived. In addition, when the client terminates the Conference Control Leg the Media Server automatically terminates all participant legs. The Conference Control Leg is also used for for play or record operations to/from the entire conference and for active talker notifications. Full conference media operations and active talker report subscriptions MUST beperformedexecuted on the Conference Control Leg.Van Dyke, et al. Expires September 1, 2006 [Page 10] Internet-Draft MSCML February 2006Creation of a Conference Control Leg is RECOMMENDED because full advanced conferencing capabilities are not available without it. Clients MUST establish the Conference Control Leg in the initial INVITE that creates the conference; it cannot be created later. Once the client has created the conference with or without the Conference Control Leg, participants can be joined to the conference. This is achieved by the client directing an INVITE to the Private Conference URI for each participant. Using the example conference URI given above, this would be sip:conf=UniqueID@ms.example.net . 5.2. Configure Conference Request <configure_conference> The <configure_conference> request has two attributes that control the resources the Media Server sets aside for the conference. Theseattributesare described inTable 1. NOTE: In the attribute tables the column labeled "R/O" indicates whether the attribute is required (R) or optional (O). If the attribute is only required under certain conditions the value (O*) is placed in the column. In that case there will be a note in the description preceded by an asterisk that explainsthecases where it is required. +------------------+---------+-----+--------------------------------+ | Attribute | Default | R/O | Description | +------------------+---------+-----+--------------------------------+ |list below. Attributes of <configure_conference>: o reservedtalkers| | O* |- optional (see note), no default value: The maximum number of talker| | | | |legs allocated for the| | | | |conference.*RequiredNote: required when| | | | |establishing the Conference| | | | |Control Leg but optional in| | | | |subsequent| | | | |<configure_conference>| | | | |requests.| |o reserveconfmedia| yes | O |- optional, default value "yes": Controls allocation of| | | | |resources to enable playing or| | | | |recording to or from the| | | | |entire conference| +------------------+---------+-----+--------------------------------+ Table 1: Conference AttributesWhen the reservedtalkers+1st INVITE arrives at the media server, the media server MUST generate a 486 Busy Here response. NOTE: It would be symmetric to have a reservedlisteners parameter. However, the practical limitation on the Media Server is the number of talkers for a mixer to monitor. In either case, theVan Dyke, et al. Expires September 1, 2006 [Page 11] Internet-Draft MSCML February 2006client regulates who gets in to the conference by either proxying the INVITEs from the user agent clients or metering to whom it gives the conference URI. For example, to create a conference with up to 120 active talkers and Van Dyke, et al. Expires November 27, 2006 [Page 10] Internet-Draft MSCML May 2006 the ability to play audio into the conference or record portions or all of the conference full mix, theapplication serverclient specifies both attributes, as shown in Figure 6. <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <request> <configure_conference reservedtalkers="120" reserveconfmedia="yes"/> </request> </MediaServerControl> Figure 6: 120 Speaker MSCML ExampleFigure 7 shows a conference with up to five active speakers without the capability to play or record audio into the conference. <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <request> <configure_conference reservedtalkers="5" reserveconfmedia="no"/> </request> </MediaServerControl> Figure 7: 5 Speaker MSCML ExampleIn addition to these attributes a <configure_conference> request MAY contain a child <subscribe> element. The <subscribe> element is used to request notifications for conference wide active talker events. Detailed information regarding active talker events is contained in Section 5.7. The client MUST include a <configure_conference> request in the initial INVITE which establishes the conference when creating the Conference Control Leg. The client server MUST issue asynchronous commands, such as <play>, separately (i.e., in INFO messages) to avoid ambiguous responses. Media operations on the Conference Control leg are performed internally, with no need for external RTP streams. Accordingly, the Media Server does not expect RTP on the Conference Control Leg. Therefore, the client MUST send either no SDP or hold SDP in the INVITE request containing a <configure_conference> payload. TheVan Dyke, et al. Expires September 1, 2006 [Page 12] Internet-Draft MSCML February 2006Media Server MUST treat SDP with all media lines set to "inactive" or with connection addresses set to 0.0.0.0 (for backwards compatibility) as hold SDP. The Media Server sends a response when it has finished processing the <configure_conference> request. The format of the <configure_conference> response is detailed in Section 10.2. 5.3. Configure Leg Request <configure_leg> Conference legs have a number of properties the clientservercan modify. These are set using the <configure_leg> request. This request has the attributesand defaults showndescribed inTable 2. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |the list below. Attributes of <configure_leg>: Van Dyke, et al. Expires November 27, 2006 [Page 11] Internet-Draft MSCML May 2006 o type| talker | O |- optional, default value "talker": Consider this leg's audio for| | | | |inclusion in the output mix.| | | | |Alternative is "listener".| |o dtmfclamp| yes | O |- optional, default value "yes": Remove detected DTMFdigitdigits from the| | | | |input audio.| |o toneclamp| yes | O |- optional, default value "yes": Remove tones from the input audio.| | | | |Tones include call progress tones and| | | | |the like.| |o mixmode| full | O |- optional, default value "full": Be a candidate for the full mix.| | | | |Alternatives are "mute" to not allow| | | | |audio in the mix, "parked" to remove| | | | |any media streams from the leg,| | | | |"preferred" to give this stream| | | | |preferential selection in the mix| | | | |(i.e., even if not loudest talker,| | | | |includemedia,media if present, from this| | | | |leg in the mix) and "private" which| | | | |enables personalized mixes.| +-----------+---------+-----+---------------------------------------+ Table 2: Conference Leg AttributesIn addition to these attributes, there are four child elements defined for <configure_leg>. These are <inputgain>, <outputgain>, <configure_team> and <subscribe>. The first two, <inputgain> and <outputgain>, modify the gain applied to the input and output audio streams respectively. These may contain <auto>, to use automatic gain control (AGC) or <fixed>. The <auto> element has the attributes "startlevel", "targetlevel", and "silencethreshold". All of the parameters are in dB. The <fixed>Van Dyke, et al. Expires September 1, 2006 [Page 13] Internet-Draft MSCML February 2006element has the attribute "level", which is in dB. The default for both <inputgain> and <outputgain> is <fixed>. The Media Server MAY silently cap or ignore <inputgain> or <outputgain> requests which exceed the gain limits imposed by the platform. The <configure_team> element is used to create and manipulate groups for personalized mixes. Details of personalized mixes are discussed in Section 5.8. The <subscribe> element is used to request notifications for call leg related events such as asynchronous DTMF digit reports. Detailed information regarding call leg events is discussed in Section 7. If the default parameters are acceptable for the leg the client wishes to enter into the conference, then a normal SIP INVITE, with no MSCML body, is sufficient. However, if the client wishes to modify one or more of the parameters, the client can include a MSCML body in addition to the SDP body. The client can modify the conference leg parameters during the conference by issuing a SIP INFO on the dialog representing the conference leg. Of course, the client cannot modify SDP in an INFO message. The Media Server sends a response when it has finished processing the <configure_leg> request. The format of the <configure_leg> response Van Dyke, et al. Expires November 27, 2006 [Page 12] Internet-Draft MSCML May 2006 is detailed in Section 10.3. 5.4. Terminating a Conference To remove a leg from the conference, the client issues a SIP BYE request on the selected dialog representing the conference leg. The client can terminate all legs in a conference by issuing a SIP BYE request on the Conference Control Leg. If one or more participants are still in the conference when the media server receives a SIP BYE request on the Conference Control Leg, the media server issues SIP BYE requests on all of the remaining conference legs to ensure clean up of the legs. The media server returns a 200 OK to the SIP BYE request as it sends BYE requests to the other legs. This is because we cannot issue a provisional response to a non-INVITE request, yet the teardown of the other legs may exceed the retransmission timer limits of the original request. While the conference is being cleaned up the Media Server MUST reject any new INVITEs to the terminated conference with a 486 Busy Here response. This response indicates that the specified conference cannot accept new participants.Van Dyke, et al. Expires September 1, 2006 [Page 14] Internet-Draft MSCML February 20065.5. Conference Manipulation Once the conference has begun, the client can manipulate the conference as a whole or a particular participant leg by issuing commands on the associated SIP dialog. For example, by sending MSCML requests on the Conference Control Leg the client can request the media server to record the conference, play a prompt to the conference or request reports on active talker events. Similarly, the client may mute a participant leg, configure a personalized mix or request reports for call leg events such as DTMF keypresses. Figure8 and Figure 9 show two sample commands. The first7 shows an example MSCML command which plays a promptinto the conference. The second records the entire conference to the URL specified by the 'recurl' attribute. This "file://" URL scheme happens to do the write over NFS, per configuration at the media server. NOTE: The provisioning of NFS mount points and their mappingtothe "file://" schema is purely a local matter at the media server.all conference participants. <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <request> <play> <prompt> <audio url="http://prompts.example.net/en_US/welcome.au"/> </prompt> </play> </request> </MediaServerControl> Figure8:7: Full Conference Audio Command - Play<?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <request> <playrecord recurl="file://archive.example.net/archives/011208.au" beep="no" initsilence="infinite" endsilence="infinite" duration="infinite"/> </request> </MediaServerControl> Figure 9: Full Conference Audio Command - Record The response to this last request will be similar to the one shown in Figure 10.Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page15]13] Internet-Draft MSCMLFebruaryMay 2006<?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <response request="playrecord" code="200" text="OK" playduration="0" playoffset="0" reclength="1420374" recduration="177540"/> </MediaServerControl> Figure 10: Sample Change Command ResponseA client can modify a leg by issuing an INFO on the dialog associated with the participant leg. For example, Figure118 mutes a conference leg. <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <request> <configure_leg mixmode="mute"/> </request> </MediaServerControl> Figure11:8: Sample Change Leg Command In Figure8,7, we saw a request to play a prompt to the entire conference. The client can also request to play a prompt to an individual call leg. In that case, the MSCML request is issued within the SIP dialog of the desired conference participant. Section 6 describes the interactive voice response (IVR) services offered by MSCML. If an IVR command arrives on the control channel, it takes effect on the whole conference. This is a mechanism for playing prompts to the entire conference (e.g., announcing new participants). If an IVR command arrives on an individual leg, it only affects that leg. This is a mechanism for interacting with users, such as the creation of "waiting rooms", allowing a user to mute themselves using key presses, allowing a moderator to out-dial, etc. A participant leg MUST be configured with mixmode="parked" prior to the issuance of any IVR commands with prompt content ('prompturl' attribute or <prompt> element). Parking the leg isolates the participant's input and output media from the conference and allows use of those streams for playing and recording purposes. However, the mixmode has no effect if just digit collection or recording is desired. <playcollect> and <playrecord> requests without prompt content MAY be sent on participant legs without setting mixmode="parked".Van Dyke, et al. Expires September 1, 2006 [Page 16] Internet-Draft MSCML February 20065.6. Video Conferencing MSCML controlled advanced conferences as well as RFC 4240 [2] controlled basic conferences implicitly support video conferencing in the form of video switching. In video switching the video stream of the loudest talker (with some hysteresis) is sent to all participants other than that talker. The loudest talker receives the video stream from the immediately prior loudest talker. Media Servers MUST ensure that participants receive video media Van Dyke, et al. Expires November 27, 2006 [Page 14] Internet-Draft MSCML May 2006 compatible with their session. For example, a participant who has established an H.263 video stream will not receive video from another participant employing H.264 media. Media Servers SHOULD implement video transcoding to minimize media incompatibilities between participants. The Media Server MUST switch video streams only when it receives a refresh video frame. A refresh frame contains all of the video information required to decode that frame (i.e. there is no dependency on data from previous video frames). Refresh frames are large and generally sent infrequently to conserve network bandwidth. The Media Server MUST implement standard mechanisms to request that the new loudest talker's video encoder transmits a refresh frame to ensure video can be switched quickly. 5.7. Conference Events A client can subscribe for periodic active talker event reports which indicate which participants are included in the conference mix. As these are conference level events the subscription and notifications are sent on the Conference Control Leg. Media Servers MAY impose limits on the minimum interval for active talker reports for performance reasons. If the client request is below the imposed minimum the Media Server SHOULD set the interval to the minimum value supported. To limit unnecessary notification traffic the Media Server SHOULD NOT send a report if the active talker information for the conference has not changed during the reporting interval. A request for an active talker report is in Figure12.9. The active talker report enumerates the current call legs in the mix.Van Dyke, et al. Expires September 1, 2006 [Page 17] Internet-Draft MSCML February 2006<?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <request> <configure_conference> <subscribe> <events> <activetalkers report="yes" interval="60s"/> </events> </subscribe> </configure_conference> </request> </MediaServerControl> Figure12:9: Active Talker Request Van Dyke, et al. Expires November 27, 2006 [Page 15] Internet-Draft MSCML May 2006 Event notifications are sent in SIP INFO messages. Figure1310 shows an example report. <?xml version="1.0" encoding="utf-8"?> <MediaServerControl version="1.0"> <notification> <conference uniqueid="ab34h76z" numtalkers="47"> <activetalkers> <talker callid="myhost4sn123"/> <talker callid="myhost2sn456"/> <talker callid="myhost12sn78"/> </activetalkers> </conference> </notification> </MediaServerControl> Figure13:10: Active Talker Event Example The value of the "callid" attribute in the <talker> element corresponds to the value of the SIP Call-ID header of the associated dialog. This enables the client to associate the active talker with a specific participant leg. 5.8. Conferencing With Personalized Mixes MSCML enables clients to create personalized mixes through the <configure_team> element for scenarios where the standard mixmode settings do not provide sufficient control. The <configure_team> element is a child of <configure_leg>. To create personalized mixes the client has to identify the relationships among the participants. This is accomplished by manipulating two MSCML objects. These objects are:Van Dyke, et al. Expires September 1, 2006 [Page 18] Internet-Draft MSCML February 2006o The list of team members (<teammate> elements) set using <configure_team> o The mixmode attribute set through <configure_leg> The media server uses the values of these objects to determine which audio inputs to combine for output to the participant. In a normal conference, each participant hears the conference mix minus their own input if they are part of the mixed output. The team list enables the client to specify other participants that the leg can hear in addition to the normal mixed output. Note that personalized mix settings apply only to audio media and do not affect video switching. Team relationships are implicitly symmetric. If the client sets participant A as a team member of participant B, then the media server automatically sets participant B as a team member for A. Van Dyke, et al. Expires November 27, 2006 [Page 16] Internet-Draft MSCML May 2006 The id attribute set through <configure_leg> is used to identify the various participants. A unique ID MUST be assigned to each participant included in a personalized mix. The ID's used MUST be unique within the scope of the conference in which they appear. By itself, the team list only defines those participants that the leg can hear. The mixmode attribute of each team member determines whether to include their audio input in the personalized mix. If the client sets the teammate's mixmode to private, then it is part of the mix. If the mixmode is set to any other value, it is not. 5.8.1. MSCML Elements and Attributes for Personalized Mixes Control of personalized mixes rely on two major MSCML elements. o <configure_leg> using the mixmode attribute, mixmode="private" o <configure_team> The <configure_team> element allows the user to make the participants members of a team within a specific conference. It is a child of the <configure_leg> parent element. The client sends the <configure_team> element in a <configure_leg> request in either a SIP INVITE or SIP INFO. o In an INVITE to join a participant whose properties differ from the properties established for the conference as a whole. o In an INFO to change the properties for an existing leg. The two attributes of the configure_team element are "id" and "action". The id attribute MUST contain the unique ID of the leg being modified, as set in the original <configure_leg> request. The action attribute can take on the values "add", "delete", "query", and "set". The default value is "query". This attribute allows the userVan Dyke, et al. Expires September 1, 2006 [Page 19] Internet-Draft MSCML February 2006to modify the team list. Table31 describes the actions that can be performed on the team list. +--------+----------------------------------------------------------+ | Action | Description | +--------+----------------------------------------------------------+ | add | Adds a teammate to the mix. | | delete | Deletes a teammate from the mix. | | query | Returns the teammate list to the requestor. This is the | | | default value. | Van Dyke, et al. Expires November 27, 2006 [Page 17] Internet-Draft MSCML May 2006 | set | Creates a team list when followed by <teammate id="n"> | | | and also removes all the teammates from the team list | | | for example, when the creator (originator) of the team | | | list on that specific conference leg wants to remove all | | | of the teammates from the team. If the set operation | | | removes all teammates from a participant, that | | | participant hears the full conference mix. | +--------+----------------------------------------------------------+ Table3:1: Configure Team Actions 5.8.2. Example Usage of Personalized Mixes A common use of personalized mixing is to support coaching of one participant by another. The coaching scenario includes three participants: o Coach (supervisor) who coaches the agent o Agent who interacts with the client o Client (customer) who receives advice from the agent Table42 illustrates the details of the coached conference topology. +-------------+------------+------------+---------+-----------------+ | Participant | ID | Team | Mixmode | Hears | | | | Members | | | +-------------+------------+------------+---------+-----------------+ | Supervisor | supervisor | Agent | Private | customer + | | | | | | agent | | Agent | agent | Supervisor | Full | customer + | | | | | | supervisor | | Customer | customer | none | Full | agent | +-------------+------------+------------+---------+-----------------+ Table4:2: Coached Conference Example To create this topology, the client performs the followng actions:Van Dyke, et al. Expires September 1, 2006 [Page 20] Internet-Draft MSCML February 20061. Join each leg to the conference, being certain to include a unique ID in the <configure_leg> request. The leg ID needs to be unique only within the scope of the conference to which it belongs. 2. Configure the teammate list and mixmode of each participant as required. Both actions (step 1 and 2) may be combined in a single MSCML request. The following sections detail these actions and their corresponding MSCML payloads. Van Dyke, et al. Expires November 27, 2006 [Page 18] Internet-Draft MSCML May 2006 5.8.2.1. Create the Conference Before joining any participants, the client must create the conference by sending a SIP INVITE which contains an MSCML <configure_conference> request with a unique conference identifier. 5.8.2.2. Joining and Configuring the Coach Join the coach leg to the conference and configure its desired properties by sending a SIP INVITE containing a <configure_leg> request. The <configure_leg> element sets the leg's unique ID to supervisor and its mixmode to private. The corresponding MSCML request is as follows. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg id="supervisor" mixmode="private"/> </request> </MediaServerControl> Figure14:11: Join Coach RequestThe media server responds as follows. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="configure_leg" code="200" text="OK"/> </MediaServerControl> Figure 15: Join Coach Response Table 5 depictsNote that theconference configuration after the coach has been joined. Van Dyke, et al. Expires September 1, 2006 [Page 21] Internet-Draft MSCML February 2006 +-------------+------------+--------------+---------+---------+ | Participant | ID | Team Members | Mixmode | Hears | +-------------+------------+--------------+---------+---------+ | Supervisor | supervisor | none | Private | Silence | +-------------+------------+--------------+---------+---------+ Table 5: Conference After Joining the Coach Note that the client cannot configure the teammate list forclient cannot configure the teammate list for the coach yet because there are no other participants in the conference. One must join a participant to the conference before one can add it as a teammate for another leg. 5.8.2.3. Joining and Configuring the Agent Join the agent leg to the conference and configure its desired properties by sending a SIP INVITE containing a <configure_leg> request. The <configure_leg> element sets the leg's unique ID to "agent" and sets the supervisor as a team member of the agent. Because team member relationships are symmetric, this action also adds the agent as a team member for the coach. The corresponding MSCML request is as follows. Van Dyke, et al. Expires November 27, 2006 [Page 19] Internet-Draft MSCML May 2006 <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg id="agent"> <configure_team action="set"> <teammate id="supervisor"/> </configure_team> </configure_leg> </request> </MediaServerControl> Figure16:12: Join Agent Request Because the desired mixmode for this leg is full, which is the default value, there is no need to set it explicitly.The media server responds as follows. Van Dyke, et al. Expires September 1, 2006 [Page 22] Internet-Draft MSCML February 2006 <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="configure_leg" code="200" text="OK"> <team id="agent" numteam="1"> <teammate id="supervisor"/> </team> </response> </MediaServerControl> Figure 17: Join Agent Response Table 6 shows the conference configuration after the agent has been joined. +-------------+------------+--------------+---------+------------+ | Participant | ID | Team Members | Mixmode | Hears | +-------------+------------+--------------+---------+------------+ | Supervisor | supervisor | agent | Private | agent | | Agent | agent | supervisor | Full | supervisor | +-------------+------------+--------------+---------+------------+ Table 6: Conference After Joining Agent5.8.2.4. Joining and Configuring the Client Join the client leg to the conference and configure its desired properties by sending a SIP INVITE containing a <configure_leg> request. The <configure_leg> element simply sets the leg's unique ID to "customer." The media server does not need further configuration because the desired mixmode, full, is the default and the customer has no team members. The corresponding MSCML request is as follows. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg id="customer"/> </request> </MediaServerControl> Figure18:13: Join Client Request Strictly speaking, it is not a requirement that the client give the customer leg a unique ID because it will not be a team member. However, when using coached conferencing, we RECOMMEND one assign a unique ID to each leg in the initial INVITE request. Assigning a unique ID eliminates the need to set it later by sending a SIP INFO if one later desires personalized mixing for the customer leg. The conference is now in the desired configuration shown previously in Table 2. 6. Interactive Voice Response (IVR) Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page23]20] Internet-Draft MSCMLFebruaryMay 2006After receivingIn theprevious MSCML request,IVR model, the Media Server acts as a media processing proxy for the UAC. This is particularly useful when the UAC is a media gateway or other device with limited media processing capability. The typical use case for MSCML is when there is an application serverresponds as follows. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="configure_leg" code="200" text="OK"/> </MediaServerControl> Figure 19: Join Client Response Table 7 illustrates the final conference configuration. +-------------+------------+------------+---------+-----------------+ | Participant | ID | Team | Mixmode | Hears | | | | Members | | | +-------------+------------+------------+---------+-----------------+ | Supervisor | supervisor | agent | Private | customer + | | | | | | agent | | Agent | agent | supervisor | Full | customer + | | | | | | supervisor | | Customer | customer | none | Full | agent | +-------------+------------+------------+---------+-----------------+ Table 7: Final Coached Conference Configuration 5.8.2.5. Response to Configure Team With Query Action If the action attribute of <configure_team> has the value "query" the media server responds with the current list of team members and their number. The numteam attribute in the response indicates how many members are on the team. The following example shows that there is one team member, identified as "agent", on the team for the participant identified as "super." <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="configure_leg" code="200" text="OK"> <team id="supervisor" numteam="1"> <teammate id="agent"/> </team> </response> </MediaServerControl> Figure 20: Number of Team Members If the MSCML <configure_team> specifies an invalid ID, the media server MUST ignore the invalid ID and treat the request as a query. Van Dyke, et al. Expires September 1, 2006 [Page 24] Internet-Draft MSCML February 2006 5.8.2.6. Exiting the Conference When the agent hangs up, the client removes the agent's leg from the supervisor's team list and from the entire conference. This process works exactly like the BYE method; the media server does not send a message to other members of the conference. The media server does not keep track of old team lists or names of old team lists. Former team members must re-join using the MSCML <configure_team> element as previously described. 6. Interactive Voice Response (IVR) In the IVR model, the Media Server acts as a media processing proxy for the UAC. This is particularly useful when the UAC is a media gateway or other device with limited media processing capability. The typical use case for MSCML is when there is an application server that isthat is the MSCML client. The client can use the SIP Service URI concept (RFC 3087) to initiate a service. The client then uses RFC 4240 [2] to initiate a MSCML session on a media server. These relationships are shown in Figure21.14. SIP +--------------+ Service URI | Application | /---------------| Server | /(e.g., RFC3087) +--------------+ / | MSCML / SIP | Session / +--------------+ +-----+/ RTP | | | UAC |=====================| Media Server | +-----+ | | +--------------+ Figure21:14: IVR Model The IVR service supports basic Interactive Voice Response functions, playing announcements, collecting DTMF digits, and recording, based on Media Server Control Markup Language (MSCML) directives added to the message body of a SIP request. The major MSCML IVR requests are <play>, <playcollect> and <playrecord>. Multifunction media servers MUST use the URI conventions described in RFC 4240 [2]. The service indicator for MSCML IVR MUST be set to "ivr" as shown in the following example. sip:ivr@ms.example.netVan Dyke, et al. Expires September 1, 2006 [Page 25] Internet-Draft MSCML February 2006The VoiceXML IVR service indicator is "dialog". This service indicator MUST not be used for any other interactive voice response control mechanism. The Media Server MUST accept MSCML IVR payloads in INFO requests and MUST NOT accept MSCML IVR payloads in the initial or subsequent INVITEs. The INFO method reduces certain timing issues that occur with INVITEs and requires less processing on both the client and Media Server. The Media Server notifies the client that the command has completed through a <response> message containing final status information and associated data such as collected DTMF digits. Van Dyke, et al. Expires November 27, 2006 [Page 21] Internet-Draft MSCML May 2006 The Media Server does not queue IVR requests. If the Media Server receives a new IVR request while another is in progress, the media server stops the first operation and it carries out the new request. The Media Server generates a <response> message for the first request and returns any data collected up to that point. If a client wishes to stop a request in progress but does not wish to initiate another operation, it issues a <stop> request. This also causes the Media Server to generate a <response> message. The Media Server treats a SIP re-INVITE which modifies the established SDP parameters as an implicit <stop> request. Examples of such SDP modifications are receiving hold SDP or removing an audio or video stream. When this occurs the Media Server immediately terminates the running <play>, <playcollect> or <playrecord> request, and sends a <response>, indicating "reason=stopped". 6.1. Specifying Prompt Content The MSCML IVR requests support two methods of specifying content to be delivered to the user. These are the <prompt> element and the prompturl attribute. Clients MUST NOT utilize both methods in a single IVR request. Clients SHOULD use the more flexible <prompt> mechanism. Use of the prompturl attribute is deprecated and may not be supported in future MSCML versions. 6.1.1. Use of the Prompt Element The <prompt> element MAY be included in the body of a <play>, <playcollect>, or <playrecord> request to specify a prompt sequence to be delivered to the caller. The prompt sequence consists of one or more references to physical content files, spoken variables or dynamic URLs which return a sub-sequence of files or variables.Figure 23 shows a sample prompt block. Van Dyke, et al. Expires September 1, 2006 [Page 26] Internet-Draft MSCML February 2006 <prompt stoponerror="yes" baseurl="file:////var/mediaserver/prompts/" locale="en_US" offset="0" gain="0" rate="0" delay="0" duration="infinite" repeat="1"> <audio url="num_dialed.raw" encoding="ulaw"/> <variable type="dig" subtype="ndn" value="3014170700"/> <audio url="num_invalid.wav"/> <audio url="please_check.wav"/> </prompt> Figure 23: Prompt Block Example Table 8 describesIn addition, the <prompt> element has several attributes which control playback of the<prompt> element and their uses. +-------------+----------+-----+------------------------------------+ | Attribute | Default | R/O | Description | +-------------+----------+-----+------------------------------------+ |included content. These are described in the list below. Attributes of <prompt>: o baseurl| | O |- optional, no default value: For notational convenience as well| | | | |as reducing the MSCML payload| | | | |size, the "baseurl" attribute is| | | | |used to specify a base URL which| | | | |is prepended to any other URLs in| | | | |the sequence which arenot fully | | | | |not fully qualified.| |o delay| 0 | O |- optional, default value "0": The "delay" attribute to the| | | | |prompt element specifies the time| | | | |to pause between repetitions of| | | | |the <prompt> sequence. It has no| | | | |effect on the first iteration of| | | | |the sequence. Expressed as a time| | | | |value (Section 4.2.1) from 0| | | | |onwards.| |Van Dyke, et al. Expires November 27, 2006 [Page 22] Internet-Draft MSCML May 2006 o duration| infinite | O |- optional, default value "infinite: The "duration" attribute to the| | | | |prompt element controls the| | | | |maximum amount of time which may| | | | |elapse while media server repeats| | | | |the sequence. This allows the| | | | |client to set an upper bound on| | | | |the length of play. Expressed as a| | | | |time value (Section 4.2.1) from 1| | | | |onwards or the strings "immediate"| | | | |and "infinite". "Infinite" directs| | | | |the Media Server to end play| | | | |immediately whereas "infinite"| | | | |indicates that the Media Server| | | | |imposes no limit.| Van Dyke, et al. Expires September 1, 2006 [Page 27] Internet-Draft MSCML February 2006 |o gain| 0 | O |- optional, default value "0": Sets the absolute gain to be| | | | |applied to the content contained| | | | |in <prompt>. The value of this| | | | |attribute is specified in units of| | | | |dB. The level reverts back to its| | | | |original value when playback of| | | | |the content contained in <prompt>| | | | |has completed.| |o gaindelta| 0 | O |- optional, default value "0": Sets the relative gain to be| | | | |applied to the content contained| | | | |in <prompt>. The value of this| | | | |attribute is specified in units of| | | | |dB. The level reverts back to its| | | | |original value when playback of| | | | |the content contained in <prompt>| | | | |has completed.| |o rate| 0 | O |- optional, default value "0": Specifies the absoluteplayback | | | | |playback rate of the content relative to| | | | |normal as either a positive| | | | |percentage (faster) or negative| | | | |percentage (slower). Any value| | | | |that attempts to set the rate| | | | |above the maximum allowed or below| | | | |the minimum allowed silently sets| | | | |the rate to the maximum or| | | | |minimum. The rate reverts back to| | | | |its original value when playback| | | | |of the content contained in| | | | |<prompt> has completed.| |o ratedelta| 0 | O |- optional, default value "0": Specifies the playback rate of the| | | | |content relative to it's current| | | | |rate as either a positive| | | | |percentage (faster) or negative| | | | |percentage (slower). Any value| | | | |that attempts to set the rate| | | | |above the maximum allowed or below| | | | |the minimum allowed silently sets| | | | |the rate to the maximum or| | | | |minimum. The rate reverts back to| | | | |its original value when playback| | | | |of the content contained in| | | | |<prompt> has completed.| Van Dyke, et al. Expires September 1, 2006 [Page 28] Internet-Draft MSCML February 2006 |o locale| | O |- optional, no default value: Specifies the language and country| | | | |variant used when resolving spoken| | | | |variables. The language is defined| | | | |as a two-letter code per ISO 639.| | | | |The country variant is also| | | | |defined as a two-letter code per| | | | |ISO 3166. These codes are| | | | |concatenated with a single| | | | |underscore (%x5F) character.| |o offset| 0 | O |- optional, default value "0": A time value (Section 4.2.1) which| | | | |specifies the time from the| | | | |beginning of the sequence at which| | | | |play is to begin. Offset only| | | | |applies to the first repetition;| | | | |subsequent repetitions begin play| | | | |at offset 0. Allowable values are| | | | |positive time values from 0| | | | |onwards. When the sequence| | | | |consists of multiple content files| | | | |the offset may select any pointin | | | | |in the sequence. If the offset value| | | | |is greater than the total time of| | | | |the sequence it will "wrap" to the| | | | |beginning and continue from there| | | | |until the media server reaches the| | | | |specified offset.| |Van Dyke, et al. Expires November 27, 2006 [Page 23] Internet-Draft MSCML May 2006 o repeat| 1 | O |- optional, default value "1": The "repeat" attribute to the| | | | |prompt element controls the number| | | | |of times the media server plays| | | | |the sequence in the <prompt>| | | | |element. Allowable values are| | | | |integers from 0 on and the string| | | | |"infinite" which indicates| | | | |repetition should occur| | | | |indefinitely. For example,| | | | |"repeat=2" means the sequence will| | | | |be played twice and "repeat=0",| | | | |which is allowed, means the| | | | |sequence is not played.| Van Dyke, et al. Expires September 1, 2006 [Page 29] Internet-Draft MSCML February 2006 |o stoponerror| no | O |- optional, default value "no": Controls media server handling and| | | | |reporting of errors encountered| | | | |when retrieving remote content. If| | | | |set to "yes" content play will end| | | | |if a fetch error occurs and the| | | | |response will contain details| | | | |regarding the failure. If set to| | | | |"no" the media server will| | | | |silently move on to the next URL| | | | |in the sequence if a fetch failure| | | | |occurs.| +-------------+----------+-----+------------------------------------+ Table 8: Prompt AttributesClients MUST NOT include both 'gain' and 'gaindelta' attributes within a single <prompt> element. Media server's SHOULD support rate controls for content. However, media servers MAY silently ignore rate change requests if content limitations do not allow the request to be honored. Clients MUST NOT include both 'rate' and 'ratedelta' attributes within a single <prompt> element. Figure 16 shows a sample prompt block. <prompt stoponerror="yes" baseurl="file:////var/mediaserver/prompts/" locale="en_US" offset="0" gain="0" rate="0" delay="0" duration="infinite" repeat="1"> <audio url="num_dialed.raw" encoding="ulaw"/> <variable type="dig" subtype="ndn" value="3014170700"/> <audio url="num_invalid.wav"/> <audio url="please_check.wav"/> </prompt> Figure 16: Prompt Block Example 6.1.1.1. <audio> and <variable> Elements Clients compose prompt sequences using the the <audio> and <variable> elements. An <audio> element MAY refer to content which contains audio, video or both; the generic name is preserved for backwards compatibility. The <audio> element hasfourthe attributesasdescribed inTable 9. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |the list below. Attributes of <audio>: Van Dyke, et al. Expires November 27, 2006 [Page 24] Internet-Draft MSCML May 2006 o url| | R |- required, no default value: The URL of the content to be| | | | |retrieved and played. The target may| | | | |be a local or remote (NFS) "file://"| | | | |scheme URL or an "http://" or| | | | |"https://" scheme URL. If the URL is| | | | |not fully qualified and a "baseurl"| | | | |attribute was set the value of the| | | | |"baseurl" attribute will be prepended| | | | |to this value to generate the target| | | | |URL.| Van Dyke, et al. Expires September 1, 2006 [Page 30] Internet-Draft MSCML February 2006 |o encoding| ulaw | O |- optional, default value "ulaw": Specifies the content encoding for| | | | |file formats that are not| | | | |self-describing (e.g. .WAV).| | | | |Allowable values are "ulaw", "alaw"| | | | |and "msgsm". This attribute only| | | | |affects "file://" scheme URLs.| |o gain| 0 | O |- optional, default value "0": Sets the absolute gain to be applied| | | | |to the content URL. The value of this| | | | |attribute is specified in units of| | | | |dB. The level reverts back to its| | | | |original value when playback of the| | | | |content URL has completed.| |o gaindelta| 0 | O |- optional, default value "0": Sets the relative gain to be applied| | | | |to the content URL. The value of this| | | | |attribute is specified in units of| | | | |dB. The level reverts back to its| | | | |original value when playback of the| | | | |content URL has completed.| |o rate| 0 | O |- optional, default value "0": Specifies the absolute playback rate| | | | |of the content relative to normal as| | | | |either a positive percentage (faster)| | | | |or negative percentage (slower). Any| | | | |value that attempts to set the rate| | | | |above the maximum allowed or below| | | | |the minimum allowed silently sets the| | | | |rate to the maximum or minimum. The| | | | |rate reverts back to its original| | | | |value when playback of the content| | | | |URL has completed.| |o ratedelta| 0 | O |- optional, default value "0": Specifies the playback rate of the| | | | |content relative to it's current rate| | | | |as either apositive percentage | | | | |positive percentage (faster) or negative percentage| | | | |(slower). Any value that attempts to| | | | |set the rate above the maximum| | | | |allowed or below the minimum allowed| | | | |silently sets the rate to the maximum| | | | |or minimum. The rate reverts back to| | | | |its original value when playback of| | | | |the content URL has completed.| +-----------+---------+-----+---------------------------------------+ Table 9: Attributes of the Audio ElementClients MUST NOT include both gain and gaindelta attributes within a single <audio> element. Media server's SHOULD support rate controls for content. However,Van Dyke, et al. Expires September 1, 2006 [Page 31] Internet-Draft MSCML February 2006Media Servers MAY silently ignore rate change requests if content limitations do not allow the request to be honored. Clients MUST NOT include both 'rate' and 'ratedelta' attributes within a single <audio> element. Media Server's MUST support local and remote (NFS) "file://" scheme URLs and "http://" and "https://" scheme URLs for content retrieval. NOTE: The provisioning of NFS mount points and their mapping to the "file://" schema is purely a local matter at the media server. Van Dyke, et al. Expires November 27, 2006 [Page 25] Internet-Draft MSCML May 2006 MSCML also supports "http://" and "https://" scheme URLS that return a list of physical URLs using the "text/uri-list" MIME type. This facility provides flexibility for applications to dynamically generate prompt sequences at execution time and enables separation of this function from the client and Media Server. Spoken variables are specified using the <variable> element. This element has the attributes described inTable 10.the list below. MSCML's spoken variables are based on those described in Audio Server Protocol [17].+-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |Attributes of <variable>: o type| | R |- required, no default value: Specifies the major type format of| | | | |the spoken variable to be played.| | | | |Allowable values are "dat" (date),| | | | |"dig" (digit), "dur" (duration),| | | | |"mth" (month), "mny" (money), "num"| | | | |(number), "sil" (silence), "str"| | | | |(string), "tme" (time) and "wkd"| | | | |(weekday).| |o subtype| | O |- optional, no default value: Specifies the minor type format of| | | | |the spoken variable to be played.| | | | |Allowable values depend on the value| | | | |of the corresponding "type"| | | | |attribute. Possible values are "mdy",| | | | |"ymd" and "dmy" for dates, "t12" and| | | | |"t24" for times, "gen", "ndn", "crd"| | | | |and "ord" for digits and "USD" for| | | | |money.| |o value| | R |- required, no default value: A string that will be interpreted| | | | |based on the formatting information| | | | |specified in the "type" and "subtype"| | | | |attributes and the "locale" attribute| | | | |of the parent <prompt> element to| | | | |render the spoken variable.| +-----------+---------+-----+---------------------------------------+ Van Dyke, et al. Expires September 1, 2006 [Page 32] Internet-Draft MSCML February 2006 Table 10: Attributes of the Variable ElementIf the "locale" attribute was not specified in <prompt> the Media Server SHOULD make a selection based on platform configuration. If the precise "locale" requested cannot be honored the Media Server SHOULD select the closest match based on the available content. IVR applications normally require specialized prompt content which is authored by the application provider. To deliver a quality user interaction the specialized prompts and spoken variables must be generated by the same speaker. Since the Media Server inherently supports multiple simultaneous applications it is extremely difficult to provision all the necessary application prompts and matching spoken variable content locally on the Media Server. Therefore we STRONGLY RECOMMEND that clients employ the dynamic URL mechanism described earlier to generate spoken variables using an external web server that returns "text/uri-list" content. 6.2. Multimedia Processing for IVR MSCML IVR requests implicitly support multimedia content. Multimedia capabilities are controlled by the audio and video media negotiated Van Dyke, et al. Expires November 27, 2006 [Page 26] Internet-Draft MSCML May 2006 for the dialog and the content specified by the client for play and record operations. If the content specified for delivery contains both audio and video tracks and the dialog has audio and video streams, both tracks are streamed to the caller. Likewise, if the dialog has both audio and video streams and the content format specified supports both (e.g. .3gp files) the Media Server records both streams to the file. If there is a mismatch between the real time media and specified content the Media Server MUST play or record the appropriate content tracks rather than failing the request. For example, if the client has requested playback of content with audio and video tracks but only audio media has been established for the dialog the Media Server should play the audio track. If the dialog has both audio and video media but the content is audio-only the Media Server MAY stream a pre-provisioned video track to the caller. Media Servers SHOULD implement video transcoding functions to minimize incompatibilities between real time media and content. The Media Server MUST begin recording video media only when it receives a refresh video frame. A refresh frame contains all of the video information required to decode that frame (i.e. there is no dependency on data from previous video frames). Refresh frames are large and generally sent infrequently to conserve network bandwidth. The Media Server MUST implement standard mechanisms to request that the caller (video encoder) transmit a refresh frameto ensure video Van Dyke, et al. Expires September 1, 2006 [Page 33] Internet-Draft MSCML February 2006to ensure video recording begins quickly. The Media Server MUST begin recording the audio track immediately while waiting to receive the video refresh frame. 6.3. Playing Announcements <play> The client issues a <play> request to play an announcement without interruption and with no digit collection. One use, for example, is to announce the name of a new participant to the entire conference. The <play> request has the attributes described inTable 11. +----------------+---------+-----+----------------------------------+ | Attribute | Default | R/O | Description | +----------------+---------+-----+----------------------------------+ |the list below. Attributes of <play>: o id| | O |- optional, no default value: Specifies a client defined ID| | | | |for purposes of matching| | | | |requests and responses.| |o offset| 0 | O |- optional, default value "0": Specifies the time from the| | | | |beginning of the URL specified| | | | |in the 'prompturl' attribute at| | | | |which play will begin. Expressed| | | | |as a time value (Section 4.2.1)| | | | |from 0 onwards. If the offset| | | | |value is greater than the total| | | | |time of the content it will| | | | |"wrap" to the beginning and| | | | |continue from there until the| | | | |media server reaches the| | | | |specified offset. NOTE: Use of| | | | |this attribute is deprecated.| |Van Dyke, et al. Expires November 27, 2006 [Page 27] Internet-Draft MSCML May 2006 o promptencoding| | O |- optional, no default value: Specifies the content encoding| | | | |for file formats that are not| | | | |self-describing (e.g. .WAV).| | | | |Allowable values are "ulaw",| | | | |"alaw" and "msgsm". This| | | | |attribute only affects "file://"| | | | |scheme URLs. NOTE: Use of this| | | | |attribute is deprecated.| |o prompturl| | O |- optional, no default value: The URL of the content to be| | | | |retrieved and played. The target| | | | |may be a local or remote (NFS)| | | | |"file://" scheme URL or an| | | | |"http://" or "https://" scheme| | | | |URL. NOTE: Use of this attribute| | | | |is deprecated.| +----------------+---------+-----+----------------------------------+ Table 11: Attributes of the Play Request Van Dyke, et al. Expires September 1, 2006 [Page 34] Internet-Draft MSCML February 2006The <play> request has one child element, <prompt>, defined. Use of <prompt> is described in Section 6.1.1. The client MUST NOT use both the <prompt> element and "prompturl" attribute in a single request. As previously discussed, the "prompturl" attribute is supported for backwards compatibility with older MSCML applications but its use is deprecated. The more flexible <prompt> element SHOULD be used instead. The following play request (Figure24)17) example shows the delivery of a complex prompt sequence consisting of content accessed via NFS and and spoken variables. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <play id="332985001"> <prompt stoponerror="yes" baseurl="file:////var/mediaserver/prompts/" locale="en_US" offset="0" gain="0" rate="0" delay="0" duration="infinite" repeat="1"> <audio url="num_dialed.raw" encoding="ulaw"/> <variable type="dig" subtype="ndn" value="3014170700"/> <audio url="num_invalid.wav"/> <audio url="please_check.wav"/> </prompt> </play> </request> </MediaServerControl> Figure24:17: <Play> Request Example When the announcement has finished playing, the Media Server sends a <response> payload to the client in a SIP INFO message. Details regarding the format of <play> responses areprovided in Section 10.4. The following <play> response (Figure 25) example depicts a valid response to the previous request. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response id="332985001" request="play" code="200" text="OK" reason="EOF" playduration="12620" playoffset="12620"> </response> </MediaServerControl> Figure 25: <Play> Response Exampleprovided in Section 10.4. Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page35]28] Internet-Draft MSCMLFebruaryMay 2006 6.4. Prompt and Collect <playcollect> The client issues a <playcollect> request to optionally play an announcement and then collect digits. The <playcollect> request is executed in two phases, prompt and collect. If the client specifies prompt content to be played, using the <prompt> element or prompturl attribute, the media server plays the content before starting the collection phase. If no prompt content is specified the collect phase begins immediately. The basic attributes of <playcollect> are the same as those of <play> which were described in Section 6.3. In addition to these basic attributes, <playcollect> defines others which control digit buffering and barge-in behavior, collection timers, special purpose DTMF key functions and logging of user DTMF input. Each functional category and its attributes are described below. 6.4.1. Control of Digit Buffering and Barge-in Whenever the media server is processing a call which specifies an MSCML service (i.e. "conf" and "ivr"), the media server continuously looks for DTMF digits and places them in a quarantine buffer. The quarantine buffer is examined when a <playcollect> request is received. The media server compares any previously buffered digits for barge-in and to look for matches with DTMF grammars or special purpose keys. This provides the type-ahead behavior for menu traversal and other types of IVR interactions.+-------------+---------+-----+-------------------------------------+ | Attribute | Default | R/O | Description | +-------------+---------+-----+-------------------------------------+ |Attributes for Control of Digit Buffering and Barge-in: o cleardigits| no | O |- optional, default value "no": Specifies whether previous user| | | | |input should be considered or| | | | |ignored for barge-in purposes and| | | | |DTMF matching. When set to "yes"| | | | |any previously buffered digits are| | | | |removed so prior user input is| | | | |ignored. If set to "no" previously| | | | |buffered digits will be considered.| | | | |If "cleardigits" is set to "no" and| | | | |barge-in is enabled previously| | | | |buffered digits will result in the| | | | |prompt being barged immediately. In| | | | |this case the prompt is not played| | | | |and digit collection begins| | | | |immediately.| Van Dyke, et al. Expires September 1, 2006 [Page 36] Internet-Draft MSCML February 2006 |o barge| yes | O |- optional, default value "yes": Specifies whether user input will| | | | |barge the prompt and force| | | | |transition to the collect phase.| | | | |When set to "yes" a DTMF input will| | | | |barge the prompt. When set to "no",| | | | |the prompt phase cannot be barged| | | | |and any user input during the| | | | |prompt is placed in the quarantine| | | | |buffer for inspection during the| | | | |collect phase. Note that If the| | | | |"barge" attribute is set to "no",| | | | |the "cleardigits" attribute| | | | |implicitly has a value of "yes".| | | | |This ensures the media server does| | | | |not leave DTMF input that occurred| | | | |prior to the current collection in| | | | |the quarantine buffer after the| | | | |request completes.| +-------------+---------+-----+-------------------------------------+ Table 12: Attributes for Control of Digit Buffering and Barge-inVan Dyke, et al. Expires November 27, 2006 [Page 29] Internet-Draft MSCML May 2006 6.4.2. Mapping DTMF Keys to Special Functions The client can define mappings between DTMF digits and special functions. The media server invokes the special function if the associated DTMF digit is detected. MSCML has two attributes which define mappings that affect termination of the collect phase. These attributes are described inTable 13. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ | escapekey | * | O |the list below. DTMF Key Mappings for <playcollect>: o escapekey - optional, default value "*": Specifies a DTMF key that indicates| | | | |the user wishes to terminate the| | | | |current operation without saving any| | | | |input collected to that point.| | | | |Detection of the mapped DTMF key| | | | |terminates the request immediately| | | | |and generates a response.| Van Dyke, et al. Expires September 1, 2006 [Page 37] Internet-Draft MSCML February 2006 |o returnkey| # | O |- optional, default value "#": Specifies a DTMF key that indicates| | | | |the user has completed input and| | | | |wants to return all collected digits| | | | |to the client. When the media server| | | | |detects the returnkey, it immediately| | | | |terminates collection and returns the| | | | |collected digits to the client in the| | | | |<response> message.| +-----------+---------+-----+---------------------------------------+ Table 13: DTMF Key Mappings for PlaycollectMSCML defines three additional mappings to enable video cassette recorder (VCR) type controls while playing a prompt sequence. Media servers SHOULD support VCR controls. However, if the media server does not support VCR controls, it MUST silently ignore DTMF inputs mapped to VCR functions and complete the <playcollect> request. The VCR control attributes are described inTable 14. +--------------+---------+-----+------------------------------------+ | Attribute | Default | R/O | Description | +--------------+---------+-----+------------------------------------+ |the list below. Attributes for VCR Controls: o skipinterval| 6s | O |- optional, default value "6s": The "skipinterval" attribute| | | | |indicates how far the media server| | | | |should skip backwards or forwards| | | | |when the rewind key (rwkey) or| | | | |fast forward key (ffkey) is| | | | |pressed, specified as a time value| | | | |(Section 4.2.1).| |o ffkey| | O |- optional, no default value: The "ffkey" attribute maps a DTMF| | | | |key to a fast forward operation| | | | |equal to the value of the| | | | |"skipinterval" attribute.| |o rwkey| | O |- optional, no default value: The "rwkey" attribute maps a DTMF| | | | |key to a rewind action equal to| | | | |the value of the "skipinterval"| | | | |attribute.| +--------------+---------+-----+------------------------------------+ Table 14: Attributes for VCR ControlsClients MUST NOT map the same DTMF digit to both the "rwkey" and "ffkey" attributes in a single <playcollect> request. VCR control operations are bounded by the beginning and end of the prompt sequence. A rewind action which moves the offset before the beginning of the sequence results in playback starting at the beginning of the sequence (i.e. offset=0). A fast forward actionVan Dyke, et al. Expires September 1, 2006 [Page 38] Internet-Draft MSCML February 2006which moves the offset past the end of the seqence results in the media server treating the sequence as completed. Van Dyke, et al. Expires November 27, 2006 [Page 30] Internet-Draft MSCML May 2006 6.4.3. Collection Timers MSCML defines several timer attributes that control how long the media server waits for digits in the input sequence. All timer settings are in milliseconds.Table 15The list below describes these attributes and their use.+------------------------+----------------+-----+-------------------+ | Attribute | Default | R/O | Description | +------------------------+----------------+-----+-------------------+ |Collection Timer Attributes: o firstdigittimer| 5000ms | O |- optional, default value "5000ms": Specifies how| | | | |long the media| | | | |server waits for| | | | |the initial DTMF| | | | |input before| | | | |terminating the| | | | |collection.| | | | |Expressed as a| | | | |time value| | | | |(Section 4.2.1)| | | | |from 1 onwards or| | | | |the strings| | | | |"immediate" and| | | | |"infinite." The| | | | |value "immediate"| | | | |indicates that| | | | |the timer should| | | | |fire immediately| | | | |whereas| | | | |"infinite"| | | | |indicates the| | | | |timer will never| | | | |fire.| |o interdigittimer| 2000ms | O |- optional, default value "2000ms": Specifies how| | | | |long the media| | | | |server waits| | | | |between DTMF| | | | |inputs.| Van Dyke, et al. Expires September 1, 2006 [Page 39] Internet-Draft MSCML February 2006 |o extradigittimer| 1000ms | O |- optional, default value "1000ms": Specifies how| | | | |long the media| | | | |server waits for| | | | |additional user| | | | |input after the| | | | |specified number| | | | |of digits has| | | | |been collected.| | | | |Expressed as a| | | | |time value| | | | |(Section 4.2.1)| | | | |from 1 onwards or| | | | |the strings| | | | |"immediate" and| | | | |"infinite." The| | | | |value "immediate"| | | | |indicates that| | | | |the timershould | | | | |should fire immediately| | | | |whereas| | | | |"infinite"| | | | |indicates the| | | | |timer will never| | | | |fire.| Van Dyke, et al. Expires September 1, 2006 [Page 40] Internet-Draft MSCML February 2006 | interdigitcriticaltime |o interdigitcriticaltimer - optional, defaults to the value of the| O |interdigittimer attribute: Specifies how| | r | interdigittime | |long the Media| | | r attribute | |Server waits| | | | |after a grammar| | | | |has been matched| | | | |for a subsequent| | | | |digit that may| | | | |cause a longer| | | | |match. Expressed| | | | |as a time value| | | | |(Section 4.2.1)| | | | |from 1 onwards or| | | | |the strings| | | | |"immediate" and| | | | |"infinite." The| | | | |value "immediate"| | | | |results in| | | | |"shortest match| | | | |first" behavior| | | | |whereas| | | | |"infinite" means| | | | |wait indefinitely| | | | |for additional| | | | |input. If not| | | | |explicitly| | | | |specified this| | | | |attribute is set| | | | |to the value of| | | | |the| | | | |'interdigittimer'| | | | |attribute.| +------------------------+----------------+-----+-------------------+ Table 15: Collection Timer AttributesThe extradigittimer setting enables the "returnkey" input to be associated with the current collection. For example, if maxdigits is set to 3 and returnkey is set to #, the user may enter either "x#", "xx#" or "xxx#", where x represents a DTMF digit. If the media server detects the "returnkey" pattern during the "extradigit" interval, the media server returns the collected digits to the client and removes the "returnkey" from the digit buffer. If this were not the case, the example would return "xxx" to the client and leave the terminating "#" in the digit buffer. At the next <playcollect> request, the media server would process the '#'. This might result in the termination of the following prompt; clearly not what the user intended. Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page41]31] Internet-Draft MSCMLFebruaryMay 2006not what the user intended.The extradigittimer has no effect unless returnkey has been set. 6.4.4. Logging Caller DTMF Input Standard SIP mechanisms, such as those discussed in Security Considerations (Section13)14) protect MSCML protocol exchanges and the information they contain. These protections do not apply to data captured in Media Server log files. In general Media Server logging is platform specific and therefore not covered by this specification. However, one aspect of logging, which is the capture of sensitive information such as personal identification numbers or credit card numbers, is relevant. The Media Server has no means to determine whether the DTMF input it receives may be sensitive as that is in the purview of the client. Recognizing this, MSCML includes a per- request mechanism to suppress logging of captured DTMF to be enabled by clients as needed. The "maskdigits" attribute controls whether detected DTMF digits appear in the log output. Clients use this attribute when the Media Server collects sensitive information that should not be accessible through the log files.+------------+---------+-----+--------------------------------------+ | Attribute | Default | R/O | Description | +------------+---------+-----+--------------------------------------+ |Maskdigits Attribute: o maskdigits| no | O |- optional, default value "no": Controls whether user DTMF inputs| | | | |are captured in media server log| | | | |files. The possible valuesfor this | | | | |for this attribute are "yes" and "no".| +------------+---------+-----+--------------------------------------+ Table 16: Maskdigits Attribute6.4.5. Specifying DTMF Grammars MSCML supports four methods for specifying DTMF grammars: the "maxdigits" attribute, which provides a simple mechanism for collecting any number of digits up to the maximum, regular expressions, MGCP [5] digit maps, and H.248.1 [6] digit maps. A media server MUST support the maxdigits and regular expression methods for specifying DTMF grammars and SHOULD support MGCP and H.248.1 methods. A client MUST NOT mix DTMF grammar types in a single <playcollect> request.Table 17 describes the detailsFollowing is a description of the "maxdigits" attribute.Van Dyke, et al. Expires September 1, 2006 [Page 42] Internet-Draft MSCML February 2006 +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |Maxdigits Attribute: o maxdigits| | O |- optional, no default value: Specifies the maximum number of DTMF| | | | |digits to be collected.| +-----------+---------+-----+---------------------------------------+ Table 17: Maxdigits AttributeThe <pattern> element specifies a digit pattern or patterns for the media server to look for. This element may contain three different child elements which specify the type of DTMF grammar used in the expression. The <pattern> element has no attributes. Van Dyke, et al. Expires November 27, 2006 [Page 32] Internet-Draft MSCML May 2006 <regex> Use regular expressions to define DTMF patterns to match. The complete regular expression syntax used in MSCML is described in Appendix A. <mgcpdigitmap> Use digit maps as specified in MGCP [5]. <megacodigitmap> Use digit maps as specified in H.248.1 [6]. At least one <regex> element MUST be present in <pattern> when regex grammars are used. Multiple <regex> elements MAY be present. When <mgcpdigitmap> or <megacodigitmap> grammars are used <pattern> MUST contain only one grammar element. The DTMF grammar elements <regex>, <mgcpdigitmap>, and <megacodigitmap> have the attributes described inTable 18. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |the list below. Attributes of DTMF Grammar Elements: o value| | R |- required, no default value: Specifies a string representing a| | | | |DTMF grammar matching the parent| | | | |element type (e.g. regex). Regex| | | | |values represent a single DTMF| | | | |grammar. MGCP and MEGACO digit maps| | | | |allow multiple grammars to be| | | | |described in a single string.| |o name| | O |- optional, no default value: Associates a client defined name for| | | | |the grammarstringwhich is sent back in| | | | |the <playcollect> response. This| | | | |attribute is most useful with regex| | | | |type grammars as each grammar element| | | | |can have a unique name.| +-----------+---------+-----+---------------------------------------+ Table 18: Attributes of DTMF Grammar Elements Van Dyke, et al. Expires September 1, 2006 [Page 43] Internet-Draft MSCML February 20066.4.6. Playcollect Response When the <playcollect> has finished playing, the MediaServer sends a <response> payload to the client in a SIP INFO message. Details of the <playcollect> response are described in Section 10.5. 6.4.7. Playcollect Examples The following <playcollect> request (Figure 26) example depicts use of the "maxdigits" attribute to control digit collection. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <playcollect id="332986004" maxdigits="6" firstdigittimer="10000" interdigittimer="5000" extradigittimer="1000" interdigitcriticaltimer="1000" returnkey="#" escapekey="*" cleardigits="no" barge="yes" maskdigits="no"> <prompt baseurl="http://www.example.com/prompts/"> <audio url="generic/en_US/enter_pin.wav"/> </prompt> </playcollect> </request> </MediaServerControl> Figure 26: <Playcollect> Request Example Using The Maxdigits Attribute If the caller enteredServer sends a <response> payload to thesix DTMF characters "196452" without exceeding any collection timersclient in a SIP INFO message. Details of the <playcollect> responsewould be as shownare described inFigure 27. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="playcollect" id="332986004" code="200" text="OK" reason="match" digits="196452" playduration="1980"> </response> </MediaServerControl> Figure 27: <Playcollect> ResponseSection 10.5. 6.4.7. Playcollect ExampleUsing The Maxdigits AttributeThe following <playcollect> request (Figure 18) examplepayloads depict thedepicts use ofregular expressions (Figure 28)the "maxdigits" attribute to control digitcollection and two possible responses which differ due to caller input. The <playcollect> request defines two named digit patterns for the Media Server to match. The first pattern, identified as "pin" consists of 4 to 6 DTMF characters. The second pattern, identified as "help", consists of a single "0" character.collection. Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page44]33] Internet-Draft MSCMLFebruaryMay 2006 <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <playcollect id="332986004" maxdigits="6" firstdigittimer="10000" interdigittimer="5000" extradigittimer="1000" interdigitcriticaltimer="1000" returnkey="#" escapekey="*" cleardigits="no" barge="yes" maskdigits="no"> <prompt baseurl="http://www.example.com/prompts/"> <audio url="generic/en_US/enter_pin.wav"/> </prompt><pattern> <regex value="x{4,6}" name="pin"/> <regex value="0" name="help"/> </pattern></playcollect> </request> </MediaServerControl> Figure28:18: <Playcollect> Request Example UsingRegular Expressions If the caller entered the DTMF string "1234" the "pin" grammar would be matched. In that case the corresponding response would be as shown in Figure 29. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="playcollect" id="332986004" code="200" text="OK" reason="match" digits="1234" name="pin" playduration="1980" playoffset="1980"> </response> </MediaServerControl> Figure 29: <Playcollect> Response Example Using Regular Expressions If the caller pressed "0" the "help" grammar would be matched and the response would be as shown in Figure 30. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="playcollect" id="332986004" code="200" text="OK" reason="match" digits="0" name="help" playduration="1980" playoffset="1980"> </response> </MediaServerControl> Figure 30: <Playcollect> Response Example Using Regular Expressions Van Dyke, et al. Expires September 1, 2006 [Page 45] Internet-Draft MSCML February 2006The Maxdigits Attribute 6.5. Prompt and Record <playrecord> The <playrecord> request directs the media server to convert and possibly transcode the the RTP payloads it receives and store them to the specified URL using the requested content codec(s) and file format. This request proceeds in two phases; prompt and record. The <playrecord> request shares the basic attributes of <play> and <playcollect> as described in Section 6.3. MSCML also defines other attributes that control the behavior of the prompt and recording phases. These phases and the attributes that control them are described in the text and tables below. 6.5.1. Prompt Phase The presence or absence of a "prompturl" attribute or child <prompt> element controls whether or not a prompt is played before recording begins. As previously noted, use of the "prompturl" attribute is deprecated and clients SHOULD use <prompt> instead. When the client requests the media server to prompt the caller before recording audio, <playrecord> has two stages. The first is equivalent to a <playcollect> operation. The client may set the prompt phase to be interruptible by DTMF input (barge) and may specify an escape key that will terminate the <playrecord> request before the recording phase begins.Table 19The list below describes the attributes of <playrecord> that specify the behavior of the prompt phase of the request. Playrecord Attributes for the Prompt Phase: Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page46]34] Internet-Draft MSCMLFebruaryMay 2006+-------------+---------+-----+-------------------------------------+ | Attribute | Default | R/O | Description | +-------------+---------+-----+-------------------------------------+ |o barge| yes | O |- optional, default value "yes": Specifies whether user input will| | | | |barge the prompt and force| | | | |transition to the record phase.| | | | |When set to "yes" a DTMF input will| | | | |barge the prompt. When set to "no",| | | | |the prompt phase cannot be barged| | | | |and any user input during the| | | | |prompt is placed in the quarantine| | | | |buffer for inspection during the| | | | |collect phase. Note that If the| | | | |"barge" attribute is set to "no",| | | | |the "cleardigits" attribute| | | | |implicitly has a value of "yes".| | | | |This ensures the media server does| | | | |not leave DTMF input that occurred| | | | |prior to the current collection in| | | | |the quarantine buffer after the| | | | |request completes.| |o cleardigits| no | O |- optional, default value "no": Specifies whether previous user| | | | |input should be considered or| | | | |ignored for barge-in purposes. When| | | | |set to "yes" any previously| | | | |buffered digits are removed so| | | | |prior user input is ignored. If set| | | | |to "no" previously buffered digits| | | | |will be considered. If| | | | |"cleardigits" is set to "no" and| | | | |barge-in is enabled previously| | | | |buffered digits will result in the| | | | |prompt being barged immediately. In| | | | |this case the prompt is not played| | | | |and recording begins immediately.| |o escapekey| * | O |- optional, default value "*": Specifies a DTMF key that indicates| | | | |the user wishes to terminate the| | | | |current operation without saving| | | | |any input recorded to that point.| | | | |Detection of the mapped DTMF key| | | | |terminates the request immediately| | | | |and generates a response.| +-------------+---------+-----+-------------------------------------+ Table 19: Playrecord Attributes for the Prompt PhaseDetection of the escape key generates a response message, and the operation returns immediately. If the user presses any other keysVan Dyke, et al. Expires September 1, 2006 [Page 47] Internet-Draft MSCML February 2006and if the prompt is interruptible (barge="yes"), then the play stops immediately and the recording phase begins. 6.5.2. Record Phase If the request proceeds to the recording phase, the media server discards any digits from the collect phase from the quarantine buffer to eliminate unintended termination of the recording.+-------------+------------------+-----+----------------------------+ | Attribute | Default | R/O | Description | +-------------+------------------+-----+----------------------------+ |The following attributes control recording behavior. Playrecord Attributes for the Record Phase: o recurl| | R |- required, no default value: Specifies the target URL| | | | |for the recorded content.| |o recencoding| ulaw | O |- optional, default value "ulaw": Specifies the encoding of| | | | |the recorded content if it| | | | |cannot be inferred from| | | | |therecurl. Possible | | | | |recurl. Possible values are "ulaw", "alaw"| | | | |and "msgsm."| |o mode| overwrite | O |- optional, default value "overwrite": Specifies whether the| | | | |recording should overwrite| | | | |or be appended to the| | | | |target URL. Allowable| | | | |values are "overwrite" and| | | | |"append."| |o duration| infinite | O |- optional, default value "infinite": Specifies the maximum| | | | |allowable duration for the| | | | |recording. Expressed as a| | | | |time value (Section 4.2.1)| | | | |from 1 onwards or the| | | | |strings "immediate" Van Dyke, et al. Expires November 27, 2006 [Page 35] Internet-Draft MSCML May 2006 and| | | | |"infinite." The value| | | | |"immediate" indicates that| | | | |recording will end| | | | |immediately whereas| | | | |"infinite" indicates| | | | |recording should continue| | | | |indefinitely. If the| | | | |maximum duration is| | | | |reached the <playrecord>| | | | |request will terminate and| | | | |generate a response.| Van Dyke, et al. Expires September 1, 2006 [Page 48] Internet-Draft MSCML February 2006 |o beep| yes | O |- optional, default value "yes": Specifies whether a beep| | | | |should be played to the| | | | |caller immediately prior| | | | |to the start of the| | | | |recording phase. Allowable| | | | |values are "yes" and "no."| |o initsilence| 3000ms | O |- optional, default value "3000ms": Specifies how long to wait| | | | |for initial speech input| | | | |before terminating| | | | |(canceling) the recording.| | | | |Expressed as a time value| | | | |(Section 4.2.1) from 1| | | | |onwards or the strings| | | | |"immediate" and| | | | |"infinite." The value| | | | | "immediate" indicates that | | | | |"immediate" indicates that the timer should fire| | | | |immediately whereas| | | | |"infinite" directs the| | | | |media server to wait| | | | |indefinitely.| |o endsilence| 4000ms | O |- optional, default value "4000ms": Specifies how long the| | | | |media server waits after| | | | |speech has ended to stop| | | | |the recording. Expressed| | | | |as a time value| | | | |(Section 4.2.1) from 1| | | | |onwards or the strings| | | | |"immediate" and| | | | |"infinite." When set to| | | | |"infinite", the recording| | | | |will continue indefinitely| | | | |after speech has ended and| | | | |will only terminate due to| | | | |a DTMF keypress or because| | | | |the input has reached the| | | | |maximum desired duration.| |o recstopmask| 0123456789ABCD#* | O |- optional, default value "0123456789ABCD#*": Specifies a list of| | | | |individual DTMF characters| | | | |that, if detected, will| | | | |cause the recording to be| | | | |terminated. To ensure the| | | | |input of a specific keyor | | | | | keysdoes not cause the| | | | |recording to stop, remove| | | | |the DTMFkey(s)key from the| | | | |list.| +-------------+------------------+-----+----------------------------+ Van Dyke, et al. Expires September 1, 2006 [Page 49] Internet-Draft MSCML February 2006 Table 20: Playrecord Attributes for the Record PhaseMedia servers MUST support local and remote (NFS) "file://" scheme URL's in the "recurl" attribute. MSCML supports "http://" and "https://" scheme URLs indirectly through the <managecontent> (Section 8) request. The media server buffers and returns any digits collected in the prompt phase, with the exception of those contained in the the "recstopmask" attribute, in the response. The media server compares digits detected during the recording phase to the digits specified in the "recstopmask" to determine if they indicate a recording termination request. The media server ignores digits not present in the recstopmask and passes them into the recording. If DTMF input terminates the recording, the media server returns the collected digit to the client in the <response>. Once recording has begun, the Media Server writes the received media to the specified recurl URL no matter what DTMF events the media server detects. It is the responsibility of the client to examine the DTMF input returned in the <response> message to determine Van Dyke, et al. Expires November 27, 2006 [Page 36] Internet-Draft MSCML May 2006 whether the audio file should be saved or if it should be deleted and potentially re-recorded. If the endsilence timer expires, the Media Server trims the end of the recorded audio by an amount equal to the value of the "endsilence" attribute.6.5.3. Playrecord ResponseWhen the recording is finished, the Media Server generates a <response> message and sends it to the client in a SIP INFO message. Details of the <playrecord> response are described in Section 10.6.6.5.4.6.5.3. PlayrecordExamplesExample The recording example (Figure31)19) plays a prompt and records it to the destination specified in the "recurl" attribute encoded as MS-GSM in wave format.Van Dyke, et al. Expires September 1, 2006 [Page 50] Internet-Draft MSCML February 2006<?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <playrecord id="5556123" recurl="file:////nfs.example.com/rec/name.wav" recencoding="msgsm" initsilence="5000" endsilence="3000" duration="30000" barge="yes" beep="yes" mode="overwrite"cleardigits="no" escapekey="*" recstopmask="0123456789#*"> <prompt> <audio url="http://www.example.com/prompts/recordname.wav"/> </prompt> </playrecord> </request> </MediaServerControl> Figure 31: Recording Example If the recording ended because the "endsilence" timer fired and no digits were pressed the response would be as shown in Figure 32. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response id="5556123" request="playrecord" code="200" text="OK" reason="end_silence" digits="" reclength="53032" recduration="6620" playduration="1045" playoffset="1045"> </response>cleardigits="no" escapekey="*" recstopmask="0123456789#*"> <prompt> <audio url="http://www.example.com/prompts/recordname.wav"/> </prompt> </playrecord> </request> </MediaServerControl> Figure32:19: RecordingResponseExample 6.6. Stop Request <stop> The client issues a <stop> request when the objective is to stop a request in progress and not initiate another operation. This request generates a <response> message from the Media Server. The only attribute is id, which is optional. The client-defined request id correlates the asynchronous response Van Dyke, et al. Expires November 27, 2006 [Page 37] Internet-Draft MSCML May 2006 with its original request and echoes back to the client in the Media Server's response. The following MSCML payload (Figure33)20) depicts an example <stop>Van Dyke, et al. Expires September 1, 2006 [Page 51] Internet-Draft MSCML February 2006request. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <stop id="4578903"/> </request> </MediaServerControl> Figure33: Stop Example The following MSCML payload (Figure 34) depicts a valid response to the above request. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="stop" id="4578903" code="200" text="OK"/> </MediaServerControl> Figure 34:20: StopResponseExample The format of a response to a <stop> request is detailed in Section 10.2. As discussed previously, the Media Server treats a SIP re-INVITE which modifies the established SDP parameters as an implicit <stop> request. Examples of such SDP modifications are receiving hold SDP or removing an audio or video stream. When this occurs the Media Server immediately terminates the running <play>, <playcollect> or <playrecord> request, and sends a <response>, indicating "reason=stopped". 7. Call Leg Events MSCML defines event notifications which are scoped to a specific SIP dialog or call leg. These events allow a client to be notified of individual, asynchronous DTMF keypresses as well as various call progress signals. The subscription, event detection and notifications for call leg events occur in the same SIP dialog. This is different than the conference level active talker events described earlier. The subscription and notifications for active talker events occur on the conference control leg but the actual event detection occurs on one or more participant legs. Subscriptions for call leg events are made by sending an MSCML <configure_leg> request on the desired SIP dialog. Call leg events may be used with the MSCML conferencing or IVR services. When usedVan Dyke, et al. Expires September 1, 2006 [Page 52] Internet-Draft MSCML February 2006with the IVR service the <configure_leg> request SHOULD not include any conference related attributes. The media server MUST ignore these if present. Call leg event subscriptions MUST not be made on the conference control leg since it has no actual RTP media to process for event detection. The media server MUST reject a <configure_leg> request sent on the conference control leg. Van Dyke, et al. Expires November 27, 2006 [Page 38] Internet-Draft MSCML May 2006 The <configure_leg> request contains the child elements <subscribe> and <events>. The <events> element may contain two child elements which control subscriptions to call leg events. These are <keypress> and <signal>. A <configure_leg> request MUST contain at most one <keypress> element but MAY contain multiple <signal> elements which request notification of different call progress events. 7.1. Keypress Events Keypress events are used when the client wishes to receive notifications of individual DTMF events which are not tied to a specific <playcollect> request. One use of this facility is to monitor conference legs for DTMF inputs which require application intervention, for example to notify the moderator that the caller wishes to speak. Keypress events are also used when the application desires complete control of grammars and timing constraints.The MSCML fomat for keypress event subscriptions is shown in Figure 35. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <keypress report="standard|long|both|none" maskdigits="yes|no"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure 35: Keypress Event Subscription FormatWhen used in a subscription context the <keypress> element has two attributes, 'report' and 'maskdigits', which are detailed inTable 21. Van Dyke, et al. Expires September 1, 2006 [Page 53] Internet-Draft MSCML February 2006 +------------+---------+-----+--------------------------------------+ | Attribute | Default | R/O | Description | +------------+---------+-----+--------------------------------------+ |the list below. Keypress Subscription Attributes: o report| | R |- required, no default value: Possible values are 'standard',| | | | |'long', 'both' and 'none'.| | | | |'Standard' means detected digits| | | | |should be reported. 'Long' means| | | | |that long digits should be reported.| | | | |"Long" digits are defined as a| | | | |single key press held down for more| | | | |than one second, or two distinct key| | | | |presses (a "double") of the same| | | | |digit that occur within two seconds| | | | |of each other with no other| | | | |intervening digits. 'Both' means| | | | |that both 'standard' and 'long'| | | | |digit events should be reported. As| | | | |a "long" digit consists of one or| | | | |more "normal" digits, a single long| | | | |duration key press will generate one| | | | |standard event and one "long" event.| | | | |A "double" will produce two standard| | | | |events and one "long" event. 'None'| | | | |means no keypress events should be| | | | |reported; disables keypress event| | | | |reporting if enabled.| |o maskdigits| no | O |- optional, default value "no": Controls whether user DTMF inputs| | | | |are captured in media server log| | | | |files. The possible values for this| | | | |attribute are "yes" and "no".| +------------+---------+-----+--------------------------------------+ Table 21: Keypress Subscription AttributesThe media server sends an MSCML response to the subscription immediately upon receiving the request. Notifications are sent to the client when the specified events are detected.Figure 36 shows the format of keypress notifications. Van Dyke, et al. Expires September 1, 2006 [Page 54] Internet-Draft MSCML February 2006 <?xml version="1.0"?> <MediaServerControl version="1.0"> <notification> <keypress digit="[0-9]|[A-D]|#|*" length="standard|long" method="standard|long|double" interdigittime="{time value}"> <status command="idle|play|collect|record" duration={time value}/> </keypress> </notification> </MediaServerControl> Figure 36: Asynchronous DTMF Reporting Response FormatWhen used in a notification context, the <keypress> element has several attributes which are used to convey details of the event that was detected. It also contains a child element, <status>, which provides information on any MSCML request that was in progress when the event occurred. The details of these notification attributes are Van Dyke, et al. Expires November 27, 2006 [Page 39] Internet-Draft MSCML May 2006 described inTable 22. +----------------+---------+-----+----------------------------------+ | Attribute | Default | R/O | Description | +----------------+---------+-----+----------------------------------+ |the list below. Keypress Notification Attributes: o digit| | R |- required, no default value: Specifies the DTMF digit| | | | |detected. Possible values are| | | | |[0-9], [A-D], '#" or '*'.| |o length| | R |- required, no default value: Specifies the duration class of| | | | |the DTMF input. Possible values| | | | |are 'standard' or 'long'.| |o method| | R |- required, no default value: Specifies the keypress detection| | | | |method that generated the| | | | |notification. Possible values| | | | |are 'standard', 'long' and| | | | |'double'.| |o interdigittime| | R |- required, no default value: Specifies the elapsed time, as a| | | | |time value (Section 4.2.1),| | | | |between the current event| | | | |detection and the previous one.| +----------------+---------+-----+----------------------------------+ Table 22: Keypress Notification Attributes7.1.1. Keypress Subscription Examples The following example MSCML payloads depict subscriptions for all possible event types and disablingkeypress reporting. Van Dyke, et al. Expires September 1, 2006 [Page 55] Internet-Draft MSCML February 2006 Figure 37 shows a subscription for standard keypress events. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <keypress report="standard"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure 37: Standard Digit Events Subscription Figure 38 shows a subscription for long keypress events. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <keypress report="long"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure 38: Long Digit Events Subscriptionkeypress reporting. Figure3921 shows a subscription forbothstandardand longkeypress events. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <keypressreport="both"/>report="standard"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure39: Subscription for both21: Standardand LongDigit Events Subscription Figure 22 shows the client disabling keypress event notifications. Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page56]40] Internet-Draft MSCMLFebruaryMay 2006Figure 40 shows the client disabling keypress event notifications.<?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <keypress report="none"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure40:22: Disabling Keypress Event Reporting 7.1.2. Keypress Notification Examples The following MSCML payloads depict keypress event notifications caused by various types of DTMF input. Figure4123 shows a notification generated by the detection of a standard "4" DTMF digit. In this example this is the first digit detected. Thus, the 'interdigittime' attribute has a value of '0'. <?xml version="1.0"?> <MediaServerControl version="1.0"> <notification> <keypress digit="4" length="standard" method="standard" interdigittime="0"> <status command="play" duration="10"/> </keypress> </notification> </MediaServerControl> Figure41:23: Standard Keypress Notification Figure4224 shows a notification generated by detection of a long pound (#).Van Dyke, et al. Expires September 1, 2006 [Page 57] Internet-Draft MSCML February 2006<?xml version="1.0"?> <MediaServerControl version="1.0"> <notification> <keypress digit="#" length="long" method="long" interdigittime="200"> <status command="idle" duration="4"/> </keypress> </notification> </MediaServerControl> Figure42:24: Long Keypress NotificationThe following MSCML payloads depict the notifications generated by the detection of two standard pound (#) events that also meet the double sequence criteria for long digits. This scenario generates three notifications. One notification is sent for each of the two standard keypress events and one notification indicates that they comprise a long digit as well. Multiple notifications are generated because the subscription specified 'report=both', which requests notifications for both long and standard digit events. <?xml version="1.0"?> <MediaServerControl version="1.0"> <notification> <keypress digit="#" length="standard" method="standard" interdigittime="0"> <status command="idle" duration="5"/> </keypress> </notification> </MediaServerControl> Figure 43: Multiple Notification Example: First Notification <?xml version="1.0"?> <MediaServerControl version="1.0"> <notification> <keypress digit="#" length="standard" method="standard" interdigittime="1000"> <status command="idle" duration="6"/> </keypress> </notification> </MediaServerControl> Figure 44: Multiple Notification Example: Second NotificationVan Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page58]41] Internet-Draft MSCMLFebruaryMay 2006<?xml version="1.0"?> <MediaServerControl version="1.0"> <notification> <keypress digit="#" length="long" method="double" interdigittime="1000"> <status command="idle" duration="6"/> </keypress> </notification> </MediaServerControl Figure 45: Multiple Notification Example: Third Notification7.2. Signal Events MSCML supports notification of certain call progress tones through the <signal> element.The format of a subscription for signal events is shown in Figure 46. <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <signal type="ring|busy|dial|CNG|CED|400" report="yes|no"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure 46: Signal Event Subscription FormatWhen used in a subscription context the <signal> element has two attributes, 'type' and 'report', and no child elements. These attributes are detailed inTable 23. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |the list below. Signal Subscription Attributes: o report| | R |- required, no default value: Controls whether the specified signal| | | | |is reported. Possible values are| | | | |'yes' and 'no'. When set to 'yes' the| | | | |mediaserver invokes the required | | | | |server invokes the required signal detection code and reports| | | | |detected events. When set to 'no' the| | | | |media server disables the associated| | | | |signal detection code and does not| | | | |report events.| Van Dyke, et al. Expires September 1, 2006 [Page 59] Internet-Draft MSCML February 2006 |o type| | R |- required, no default value: Specifies the type of call progress| | | | |signal to detect. Possible values are| | | | |'busy', 'ring', 'CED', 'CNG' and| | | | |'400' which correspond to busy tone,| | | | |ring tone, fax CED, fax CNG and 400| | | | |Hz tone.| +-----------+---------+-----+---------------------------------------+ Table 23: Signal Subscription AttributesNOTE: The details of media server provisioning required to support country specific variants of 'busy' and 'ring' is not covered by this specification. As stated previously a single <configure_leg> request MAY contain multiple <signal> elements which request notification of different call progress tones. A single <configure_leg> request SHOULD NOT contain multiple <signal> elements that have the same 'type' attribute value. If the media server receives such a request it SHOULD honor the last element specifying that type that appears in the request. The media server generates an immediate response to the <configure_leg> subscription request and sends notifications when the specified signals are detected. A single notification is sent as soon as the specified signal has been reliably detected. If the signal persists continuously additional notifications will not be sent. If the signal is interrupted and then resumes additional notifications will be sent. Signal notifications have a single attribute "type" as described in the list below. Signal Notification Attribute: o type - required, no default value: Specifies the type of call progress signal that was detected. Possible values are 'busy', 'ring', 'CED', 'CNG' and '400' which correspond to busy tone, ring tone, fax CED, fax CNG and 400 Hz tone. Van Dyke, et al. Expires November 27, 2006 [Page 42] Internet-Draft MSCML May 2006 7.2.1. Signal Event Examples The following MSCML payloads show a signal event subscription (Figure47), response (Figure 48)25) and notification (Figure49). The cancellation (Figure 50) of an event subscription and the accompanying response (Figure 51) are also shown. Van Dyke, et al. Expires September 1, 2006 [Page 60] Internet-Draft MSCML February 200626). <?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <signal type="busy" report="yes"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure47: Signal Event Subscription <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="configure_leg" code="200" text="OK"/> </MediaServerControl> Figure 48:25: Signal Event SubscriptionResponse<?xml version="1.0"?> <MediaServerControl version="1.0"> <notification> <signal type="busy"/> </notification> </MediaServerControl> Figure49:26: Signal Event Notification<?xml version="1.0"?> <MediaServerControl version="1.0"> <request> <configure_leg> <subscribe> <events> <signal type="busy" report="no"/> </events> </subscribe> </configure_leg> </request> </MediaServerControl> Figure 50: Signal Subscription Cancellation Van Dyke, et al. Expires September 1, 2006 [Page 61] Internet-Draft MSCML February 2006 <?xml version="1.0"?> <MediaServerControl version="1.0"> <response request="configure_leg" code="200" text="OK"/> </MediaServerControl> Figure 51: Signal Subscription Cancellation Response8. Managing Content <managecontent> MSCML uses the <managecontent> request to move recorded content from the media server to remote locations using the HTTP protocol. This is a store and forward model, which requires the completion of local temporary recording before the media server can send it to the web server. This facility is useful in applications such as voice messaging where a message may be reviewed by the caller prior to being committed to persistent storage. The <managecontent> requesthascontains no childelements. 8.1. Managecontent Attributes The attributes ofelements and has the<managecontent> request areattributes described inTable 24the list below.+--------------+---------+-----+------------------------------------+ | Attribute | Default | R/O | Description | +--------------+---------+-----+------------------------------------+ |Managecontent Attributes: o src| | R |- required, no default value: Specifies the local source URL of| | | | |the content. The URL scheme must| | | | |be "file://".| |o dest| | O* |- required (see note), no default value: Specifies the destination URL. The| | | | |URL scheme must be "http://".*If | | | | |Note: If the selected action is 'delete',| | | | |this attribute is optional,| | | | |otherwise Van Dyke, et al. Expires November 27, 2006 [Page 43] Internet-Draft MSCML May 2006 it is required.| |o action| move | O |- optional, default value "move": Specifies the operation for the| | | | |media server to execute. Values| | | | |can be either 'move' or 'delete'.| | | | |The 'delete' action operates on| | | | |the local source file. After a| | | | |successful move or delete, the| | | | |media server deletes the source| | | | |file fromthe media server.its local storage. If the| | | | |request is unsuccessful, the| | | | |source file is not deleted, which| | | | |gives the client complete control| | | | |of the retry strategy.| Van Dyke, et al. Expires September 1, 2006 [Page 62] Internet-Draft MSCML February 2006 |o httpmethod| post | O |- optional, default value "post": HTTP protocol method for the media| | | | |server to use in the HTTP request.| | | | |The only values are 'post' or| | | | |'put'.| |o name| | O* |- required (see note), no default value: Specifies the field name for the| | | | |content in the form when using the| | | | |'post' method. This is not to be| | | | |confused with the "src" or "dest"| | | | |attributes.*ThisNote: This attribute is| | | | |required when the "htttpmethod"| | | | |has the value"post." | |"post" and optional otherwise. o fetchtimeout| 10000ms | O |- optional, default value "10000ms": Specifies the maximum time allowed| | | | |for the transfer to complete.| | | | |Expressed as a time value| | | | |(Section 4.2.1) from 1 onwards.| |o mimetype| | O* |- required (see note), no default value: Specifies the MIME type for the| | | | |media server to transfer the| | | | |content in. If not provided the| | | | |media server MUST infer it from| | | | |the content file extension based| | | | |on the mappings contained in| | | | |Table25. *If3. Note: If the MIME type of the| | | | |content cannot be inferred from| | | | |the file extension this attribute| | | | |is required.| +--------------+---------+-----+------------------------------------+ Table 24: Managecontent AttributesTable253 defines the MIME type values allowed in the 'mimetype' attribute and the file extensions to which they are mapped. +-----------+--------------------+ | Extension | MIME Type | +-----------+--------------------+ | alaw | audio/x-alaw-basic | | ulaw | audio/basic | | msgsm | audio/ms-gsm | | wav | audio/x-wav | | tif | image/tiff | | tiff | image/tiff | | mov | video/quicktime | | qt | video/quicktime | | 3gp | video/3gpp | | 3gpp | video/3gpp | +-----------+--------------------+ Table25:3: File Extension to MIME Type MappingsVan Dyke, et al. Expires September 1, 2006 [Page 63] Internet-Draft MSCML February 2006The ability to move or delete any local file presents a potential risk to the security of the media server system. For this reason, we Van Dyke, et al. Expires November 27, 2006 [Page 44] Internet-Draft MSCML May 2006 STRONGLY RECOMMEND implementers limit local file system access when using <managecontent>. For example, we encourage limiting access based on file ownership and/or to specific directories.8.2.8.1. Managecontent Example Following is an example (Figure 27) showing a local file on the media server being transferred to an HTTP URL using the "put" method. The client sends the following request. <?xml version="1.0"?> <MediaServerControl version="1.0" <request> <managecontent id="102" src="file:////var/mediaserver/rec/6A5GH49B.ulaw" dest="http://www.example.com/recordings/myrecording.ulaw" mimetype="audio/basic" action="move" httpmethod="put" fetchtimeout="5000"/> </request> </MediaServerControl> Figure52:27: Managecontent Example Note that the client can change the temporary file name assigned by the media server as part of this operation as shown.The media server returns a response similar to the following. <?xml version="1.0"?> <MediaServerControl version="1.0" <response id="102" request="managecontent" code="200" text="OK"/> </MediaServerControl> Figure 53: Managecontent ResponseIf the request is ambiguous, the media server MUST return a status code of "400" and text "Bad Request." If the media server is unable to execute a syntactically correct and unambiguous request it MUST return a "500" status code with the text "Server Error." For example,ifthe local file system access restrictionsdescribed earliermay prevent deletion of the specifiedfile the media server returnsfile. In this case, thefollowing. Van Dyke, et al. Expires September 1, 2006 [Page 64] Internet-Draft MSCML February 2006 <?xml version="1.0"?> <MediaServerControl version="1.0"> <response id="102" request="managecontent" code="500" text="Server Error" reason="Operation not permitted"/> </MediaServerControl> Figure 54: Managcontent Error Response The"reason" attribute in the response conveys additional details on the server error that occurred. If there is a network or remote server error, the media server provides detailed error information in the <error_info> element contained in the media server response.The following example shows that the media server received a 503 error from the remote web server. <?xml version="1.0"?> <MediaServerControl version="1.0"> <response id="102" request="managecontent" code="200" text="OK"> <error_info code="503" text="Service Unavailable" context="http://www.example.com/recordings/myrecording.ulaw"/> </response> </MediaServerControl> Figure 55: Managcontent Storage Error ResponseAdditional information regarding <managecontent> responses is provided in Section 10.7. 9. Fax Processing 9.1. Recording a Fax <faxrecord> The <faxrecord> request directs the Media Server to process a fax in answer mode. The reason for a request separate from <playrecord> is that the media server needs to know to process the T.30 [18] or T.38 [19] fax protocols. Van Dyke, et al. Expires November 27, 2006 [Page 45] Internet-Draft MSCML May 2006 The <faxrecord> request has multiple attributes and one child element, <prompt>.TheseIts attributes are described inTable 26. Van Dyke, et al. Expires September 1, 2006 [Page 65] Internet-Draft MSCML February 2006 +----------------+---------+-----+----------------------------------+ | Attribute | Default | R/O | Description | +----------------+---------+-----+----------------------------------+ |the list below. Attributes of <faxrecord>: o lclid|- optional, default value ""| O |(the empty string): A string that identifies the| | | | |called station.| |o prompturl| | O |- optional, no default value: The URL of the fax content to be| | | | |retrieved and played. The target| | | | |may be a local or remote (NFS)| | | | |"file://" scheme URL or an| | | | |"http://" or "https://" scheme| | | | |URL. NOTE: Use of this attribute| | | | |is deprecated.| | promptencoding | | O |o promptencoding - optional, no default value: Specifies the content encoding| | | | |for files that do not have a| | | | |'tif' or 'tiff' extension. The| | | | |only allowable value is "tiff".| | | | |This attribute only affects| | | | |"file://" scheme URLs. NOTE: Use| | | | |of this attribute is deprecated.| |o recurl| | O |- optional, no default value: Specifies the target URL for the| | | | |recorded content.| |o rmtid| | O |- optional, no default value: Specifies the calling station| | | | |identifier of the remote| | | | |terminal. If present, the media| | | | |server MUST reject transactions| | | | |with the remote terminal if the| | | | |remote terminal's identifier| | | | |does not match the value of| | | | |'rmtid'.| +----------------+---------+-----+----------------------------------+ Table 26: Faxrecord AttributesClients SHOULD use the more flexible <prompt> mechanism for specifying fax content. Use of the 'prompturl' attribute is deprecated and may not be supported in future MSCML versions. The <prompt> element is described in Section 6.1.1. A <prompt> element sent in a <faxrecord> request MUST not contain <variable> elements. Media servers MUST support local and remote (NFS) "file://" scheme URL's in the "recurl" attribute. MSCML supports "http://" and "https://" scheme URLs indirectly through the <managecontent> (Section 8) request. The <faxrecord> request operates in one of three modes: receive, poll, and turnaround poll. The combination of <prompt> or 'prompturl' attribute and 'recurl' attribute define the mode. Table274 describes these modes in detail. The 'prompt' column in theVan Dyke, et al. Expires September 1, 2006 [Page 66] Internet-Draft MSCML February 2006table has the value 'yes' if the request has either a <prompt> element or 'prompturl' attribute. +--------+--------+---------+---------------------------------------+ | prompt | recurl | Mode | Operation | +--------+--------+---------+---------------------------------------+ | no | no | Invalid | Request fails. | | no | yes | Receive | Record the fax to the target URL | | | | | specified in 'recurl'. | Van Dyke, et al. Expires November 27, 2006 [Page 46] Internet-Draft MSCML May 2006 | yes | no | Poll | Send fax from source specified in the | | | | | <prompt> element or 'prompturl' | | | | | attribute. If there is a 'rmtid', it | | | | | MUST match the remote terminal's | | | | | identifier, or the request will fail. | | yes | yes | TP | Turnaround Poll (TP) mode. If the | | | | | remote terminal wishes to transmit, | | | | | the media server records the fax to | | | | | the target URL specified in 'recurl'. | | | | | If the remote terminal wishes to | | | | | receive, the media server sends the | | | | | fax from the source URL contained in | | | | | <prompt> or 'prompturl'. If there is | | | | | a 'rmtid', it MUST match remote | | | | | terminal's identifier, or the send | | | | | request will fail. A receive | | | | | operation will still succeed, | | | | | however. | +--------+--------+---------+---------------------------------------+ Table27:4: Fax Receive Modes In receive mode, the media server receives the fax and writes the fax data to the target URL specified by the 'recurl' attribute. In poll mode, the media server sends a fax, but as a polled (called) device. In turnaround poll mode, the media server will record a fax that the remote machine sends. If the remote machine requests a transmission, then the media server will send the fax. When transmitting a fax the media server will advertise that it can receive faxes in the DIS message. Likewise, when receiving a fax the media server will advertise that it can send faxes in the DIS message. The media server MUST flush any quarantined digits when it receives a <faxrecord> request.Van Dyke, et al. Expires September 1, 2006 [Page 67] Internet-Draft MSCML February 20069.2. Sending a Fax <faxplay> The <faxplay> request directs the Media Server to process a fax in originate mode. The reason for a request separate from <play> is that the Media Server needs to know to process the T.30 [18] or T.38 [19] fax protocols. The <faxplay> request has multiple attributes and one child element, Van Dyke, et al. Expires November 27, 2006 [Page 47] Internet-Draft MSCML May 2006 <prompt>.TheseIts attributes are described inTable 28. +----------------+---------+-----+----------------------------------+ | Attribute | Default | R/O | Description | +----------------+---------+-----+----------------------------------+ |the list below. Attributes of <faxplay>: o lclid| | O |- optional, default value "" (the empty string): A string that identifies the| | | | |called station.| |o prompturl| | O |- optional, no default value: The URL of the content to be| | | | |retrieved and played. The target| | | | |may be a local or remote (NFS)| | | | |"file://" scheme URL or an| | | | |"http://" or "https://" scheme| | | | |URL. NOTE: Use of this attribute| | | | |is deprecated.| |o promptencoding| | O |- optional, no default value: Specifies the content encoding| | | | |for files that do not have a| | | | |'tif' or 'tiff' extension. The| | | | |onlyallowable value is "tiff". | | | | |allowable value is "tiff". This attribute only affects| | | | |"file://" scheme URLs. NOTE: Use| | | | |of this attribute is deprecated.| |o recurl| | O |- optional, no default value: Specifies the target URL for the| | | | |recorded content.| |o rmtid| | O |- optional, no default value: Specifies the calling station| | | | |identifier of the remote| | | | |terminal. If present, the media| | | | |server MUST reject transactions| | | | |with the remote terminal if the| | | | |remote terminal's identifier| | | | |does not match the value of| | | | |'rmtid'.| +----------------+---------+-----+----------------------------------+ Table 28: Faxplay AttributesClients SHOULD use the more flexible <prompt> mechanism for specifying fax content. Use of the 'prompturl' attribute is deprecated and may not be supported in future MSCML versions. The <prompt> element is described in Section 6.1.1. A <prompt> element sent in a <faxrecord> request MUST not contain <variable> elements.Van Dyke, et al. Expires September 1, 2006 [Page 68] Internet-Draft MSCML February 2006Media servers MUST support local and remote (NFS) "file://" scheme URL's in the "recurl" attribute. MSCML supports "http://" and "https://" scheme URLs indirectly through the <managecontent> (Section 8) request. The <faxplay> request operates in one of three modes: send, remote poll, and turnaround poll. The combination of <prompt> or 'prompturl' attribute and 'recurl' attribute define the mode. Table295 describes these modes in detail. The 'prompt' column in the table has the value 'yes' if the request has either a <prompt> element or 'prompturl' attribute. +--------+--------+---------+---------------------------------------+ | prompt | recurl | Mode | Operation | +--------+--------+---------+---------------------------------------+ | no | no | Invalid | Request fails. | Van Dyke, et al. Expires November 27, 2006 [Page 48] Internet-Draft MSCML May 2006 | yes | no | Send | Send fax from source specified in the | | | | | <prompt> element or 'prompturl' | | | | | attribute. If there is a 'rmtid', it | | | | | MUST match the remote terminal's | | | | | identifier, or the request will fail. | | | | | If there is a 'rmtid', it must match | | | | | remote terminal's identifier, or the | | | | | receive request will fail. | | no | yes | Poll | Send fax from source specified in the | | | | | <prompt> element or 'prompturl' | | | | | attribute, assuming the remote | | | | | terminal specifies it can receive a | | | | | fax in its DIS message. It the remote | | | | | terminal does not support reverse | | | | | polling, the request will fail. If | | | | | 'rmtid' is specified, it must match | | | | | remote terminal's identifier, or the | | | | | request will fail. | | yes | yes | TP | Turnaround Poll (TP) mode. If the | | | | | remote terminal wishes to transmit, | | | | | the media server records the fax to | | | | | the target URL specified in 'recurl'. | | | | | If the remote terminal wishes to | | | | | receive, the media server sends the | | | | | fax from the source URL contained in | | | | | <prompt> or 'prompturl'. If there is | | | | | a 'rmtid', it MUST match remote | | | | | terminal's identifier, or the send | | | | | request will fail. A receive | | | | | operation will still succeed, | | | | | however. | +--------+--------+---------+---------------------------------------+Van Dyke, et al. Expires September 1, 2006 [Page 69] Internet-Draft MSCML February 2006Table29:5: Fax Send Modes In send mode, the media server sends the fax. In remote poll mode, the client places a call on behalf of the media server. The media server requests a fax transmission from the remote fax terminal. In turnaround poll mode, the media server will record a fax that the remote machine sends. If the remote machine requests a transmission, then the media server will send the fax. When transmitting a fax the media server will advertise that it can receive faxes in the DIS message. Likewise, when receiving a fax the media server will advertise that it can send faxes in the DIS Van Dyke, et al. Expires November 27, 2006 [Page 49] Internet-Draft MSCML May 2006 message. The Media Server MUST flush any quarantined digits when it receives a <faxplay> request. 10. MSCML Response Attributes and Elements 10.1. Mechanism The Media Server acknowledges receipt of a client MSCML request sent in a SIP INVITE by sending a response of either 200 OK or 415 Bad Media Type. The Media Server responds with 415 when the SIP request contains a content type other than "application/sdp" or "application/ mediaservercontrol+xml". The Media Server acknowledges receipt of a client MSCML request sent in a SIP INFO with a 200 OK or 415 Bad Media Type. The Media Server responds with 415 if the INFO request contains a content type other than "application/mediaservercontrol+xml". The Media Server transports the MSCML <response> message in a SIP INFO request. If there is an error in the request or the Media Server cannot complete the request, the Media Server sends the <response> message very shortly after receiving the request. If the request is able to proceed, the <response> contains final status information as described below. 10.2. Base <response> Attributes All MSCML responses have the basic attributes defined inTable 30. Van Dyke, et al. Expires September 1, 2006 [Page 70] Internet-Draftthe list below. Basic MSCMLFebruary 2006 +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |Response Attributes: o id| | O |- optional, no default value: Echoes the client defined ID for| | | | |contained in the request.| |o request| | R |- required, no default value: Specifies the MSCML request type that| | | | |generated the response. Allowable| | | | |values are "configure_conference",| | | | |"configure_leg", "play",| | | | |"playcollect", "playrecord", "stop",| | | | |"faxplay", "faxrecord" and| | | | |"managecontent".| |o code| | R |- required, no default value: The final status code for the| | | | |request. MSCML uses a subset of the| | | | |status classes defined in RFC 3261| | | | |[4]. In MSCML, 2XX responses indicate| | | | |success, 4XX responses indicate| | | | |client error and 5XX responses| | | | |indicate an error on the Media| | | | |Server. There are no 1XX, 3XX or 6XX| | | | |status codes in MSCML.| |Van Dyke, et al. Expires November 27, 2006 [Page 50] Internet-Draft MSCML May 2006 o text| | R |- required, no default value: The human readable reason phrase| | | | |associated with the status code.| +-----------+---------+-----+---------------------------------------+ Table 30: Basic MSCML Response AttributesResponses to <configure_conference> and <stop> requests contain only the attributes above. MSCML responses to other requests MAY contain additional request specific attributes and elements. These are describedbelow.in the following sections. 10.3. Response Attributes and Elements for <configure_leg> Responses to <configure_leg> requests have only the base response attributes defined inTable 30.Section 10.2. However, when the request contains a <configure_team> element the response includes a <team> element describing the teammate configuration for that leg. The attributes of the <team> element are shown inTable 31. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |the list below. Attributes of <team>: o id| | R |- required, no default value: The client defined unique identifier| | | | |for the conference leg.| |o numteam| | R |- required, no default value: The number of team members for the| | | | |leg.| +-----------+---------+-----+---------------------------------------+ Van Dyke, et al. Expires September 1, 2006 [Page 71] Internet-Draft MSCML February 2006 Table 31: Attributes for <team>Additional information on each team member is conveyed by child <teammate> elements contained within <team>. Each teammate is represented by a single element in the list. The <teammate> element has a single attribute as describedin Table 32. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |below. Attributes of <teammate>: o id| | R |- required, no default value: The client defined unique identifier| | | | |for the teammate leg.| +-----------+---------+-----+---------------------------------------+ Table 32: Attributes for <teammate>10.4. Response Attributes and Elements for <play> In addition to the base response attributes defined inTable 30,Section 10.2, responses to <play> requests have the additional attributes described inTable 33. +--------------+---------+-----+------------------------------------+ | Attribute | Default | R/O | Description | +--------------+---------+-----+------------------------------------+ |the list below. MSCML Response Attributes for <play>: o reason| | O |- optional, no default value: For requests that do not complete| | | | |immediately, the "reason"| | | | |attribute conveys additional| | | | |information regarding why the| | | | |command completed. Possible values| | | | |are "stopped", indicating an| | | | |explicit or implicit <stop>| | | | |request was received and "EOF"| | | | |indicating that the end of the| | | | |specified sequence of URLs was| | | | |reached.| |o playduration| | R |- required, no default value: A time value (Section 4.2.1) that| | | | |returns the duration of the| | | | |associated content playout.|Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page72]51] Internet-Draft MSCMLFebruaryMay 2006|o playoffset| | R |- required, no default value: A time value (Section 4.2.1) that| | | | |returns the time offset into the| | | | |specified content sequence where| | | | |playwas terminated. If the | | | | |was terminated. If the initial "offset" value in the| | | | |sequence was "0", then| | | | |"playduration" and "playoffset"| | | | |are equal. However, if the the| | | | |initial offset had some other| | | | |value "playoffset" serves as a| | | | |bookmark for the client to resume| | | | |play in a subsequent request.| +--------------+---------+-----+------------------------------------+ Table 33: MSCML Response Attributes for <play>10.4.1. Reporting Content Retrieval Errors If the associated request set "stoponerror=yes" in <prompt> and an error occurred while retrieving the specified content the response will include an <error_info> element detailing the problem. This element contains the response information received from the remote content server. The <error_info> element has the attributes described inTable 34. +-----------+---------+-----+---------------------------------------+ | Attribute | Default | R/O | Description | +-----------+---------+-----+---------------------------------------+ |the list below. Attributes of <error_info>: o code| | R |- required, no default value: The status code returned by the| | | | |remote content server. For example, a| | | | |web server might return 404 to| | | | |indicate that the requested content| | | | |was not found.| |o text| | R |- required, no default value: The human readable reason phrase| | | | |returned by the remote content| | | | |server. For example, the reason| | | | |phrase "Not Found" would be returned| | | | |if the requested content was not| | | | |found| |o context| | R |- required, no default value: Contains the content URL that was| | | | |being fetched when the retrieval| | | | |error occurred. This enables the| | | | |client to know precisely which URL in| | | | |a sequence caused the problem.| +-----------+---------+-----+---------------------------------------+ Table 34: Attributes of <error_info> Van Dyke, et al. Expires September 1, 2006 [Page 73] Internet-Draft MSCML February 2006An <error_info> element MAY be present in the response to any request which contains a child <prompt> element. 10.5. Response Attributes and Elements for <playcollect> In addition to the base response attributes defined inTable 30,Section 10.2, responses to<playcolect><playcollect> requests have the additional attributes described inTable 35. +--------------+---------+-----+------------------------------------+ | Attribute | Default | R/O | Description | +--------------+---------+-----+------------------------------------+ |the list below. MSCML Response Attributes for <playcollect>: o reason| | O |- optional, no default value: For requests that do not complete| | | | |immediately, the "reason"| | | | |attribute conveys additional| | | | |information regarding why the| | | | |command completed. Possible values| | | | |are "stopped", indicating an| | | | |explicit or implicit <stop>| | | | |request was received, "match"| | | | |meaning a DTMF grammar was| | | | |matched, "timeout" indicating that| | | | |no DTMF input was received before| | | | |one of thecollection timers | | | | |collection timers expired, and "returnkey" or| | | | |"escapekey" meaning the DTMF digit| | | | |mapped to that key was detected.| | | | |the return Van Dyke, et al. Expires November 27, 2006 [Page 52] Internet-Draft MSCML May 2006 key or escape key| | | | |terminated the operation,| | | | |respectively.| |o playduration| | R |- required, no default value: A time value (Section 4.2.1) that| | | | |returns the duration of the| | | | |associated content playout. If the| | | | |caller barged the prompt this| | | | |value will reflect the play| | | | |duration up to that event.| Van Dyke, et al. Expires September 1, 2006 [Page 74] Internet-Draft MSCML February 2006 |o playoffset| | R |- required, no default value: A time value (Section 4.2.1) that| | | | |returns the time offset into the| | | | |specified content sequence where| | | | |play was terminated. If the| | | | |initial "offset" value in the| | | | |sequence was "0", then| | | | |"playduration" and "playoffset"| | | | |are equal. However, if the the| | | | |initial offset had some other| | | | |value "playoffset" serves as a| | | | |bookmark for the client to resume| | | | |play in a subsequent request. If| | | | |the caller barged the prompt this| | | | |value will reflect the time offset| | | | |at which barge-in occurred.| |o digits| | R |- required, no default value: Contains the collected DTMF input| | | | |characters. If no DTMF input was| | | | |collected this attribute is set to| | | | |the empty string ("").| |o name| | O* |- required (see note), no default value: The client defined name of the| | | | |DTMF grammar that was matched.| | | | | *ThisNote: This attribute is required if the| | | | |"name" attribute was set in the| | | | |matching DTMF grammar.| +--------------+---------+-----+------------------------------------+ Table 35: MSCML Response Attributes for <playcollect>Responses to <playcollect> requests MAY include an <error_info> element as described in Section 10.4.1. 10.6. Response Attributes and Elements for <playrecord> In addition to the base response attributes defined inTable 30,Section 10.2, responses to<playrecord> requests have the additional attributes described in Table 36. Van Dyke, et al. Expires September 1, 2006 [Page 75] Internet-Draft MSCML February 2006 +--------------+---------+-----+------------------------------------+ | Attribute | Default | R/O | Description | +--------------+---------+-----+------------------------------------+ |<playrecord> requests have the additional attributes described in the list below. o reason| | O |- optional, no default value: For requests that do not complete| | | | |immediately, the "reason"| | | | |attribute conveys additional| | | | |information regarding why the| | | | |command completed. Possible values| | | | |are "stopped", indicating an| | | | |explicit or implicit <stop>| | | | |request was received, "digit"| | | | |meaning a DTMF digit was detected| | | | |so the prompt phase was barged,| | | | |"init_silence" meaning the| | | | |recording terminated because| | | | |because of no input, "end_silence"| | | | |meaning the recording was| | | | |terminated because the| | | | |"endsilence" timer elapsed,| | | | |"max_duration" indicating that the| | | | |maximum time for the recording was| | | | |reached, "escapekey" indicating| | | | |the DTMF input mapped to| | | | |"escapekey" was detected, thus| | | | |terminating the recording and| | | | |"error" indicating a general| | | | |operation failure.| |o playduration| | R |- required, no default value: A time value (Section 4.2.1) that| | | | |returns the duration of the| | | | |associated content playout. If the| | | | |caller barged the prompt this| | | | |value will reflect the play| | | | |duration up to that event.| |Van Dyke, et al. Expires November 27, 2006 [Page 53] Internet-Draft MSCML May 2006 o playoffset| | R |- required, no default value: A time value (Section 4.2.1) that| | | | |returns the time offset into the| | | | |specified content sequence where| | | | |play was terminated. If the| | | | |initial "offset" value in the| | | | |sequence was "0", then| | | | |"playduration" and "playoffset"| | | | |are equal. However, if the the| | | | |initial offset had some other| | | | |value "playoffset" serves as a| | | | |bookmark for the client to resume| | | | |play in a subsequent request. If| | | | |the caller barged theprompt this | | | | |prompt this value will reflect the time offset| | | | |at which barge-in occurred.| Van Dyke, et al. Expires September 1, 2006 [Page 76] Internet-Draft MSCML February 2006 |o digits| | R |- required, no default value: Contains the DTMF digit that| | | | |terminated the recording. If no| | | | |DTMF input was detected this| | | | |attribute is set to the empty| | | | |string ("").| |o reclength| | R |- required, no default value: The length of the recorded content| | | | |in bytes.| |o recduration| | R |- required, no default value: A time value (Section 4.2.1)| | | | |indicating the elapsed duration of| | | | |the recording.| +--------------+---------+-----+------------------------------------+ Table 36: MSCML Response Attributes for <record>Responses to <playrecord> requests MAY include an <error_info> element as described in Section 10.4.1. 10.7. Response Attributes and Elements for <managecontent> Responses to <managecontent> requests have only the base response attributes defined inTable 30.Section 10.2. If a content transfer error occurs while executing the request the response will also contain an <error_info> element as described in Section 10.4.1. 10.8. Response Attributes and Elements for <faxplay> and <faxrecord> In addition to the base response attributes defined inTable 30,Section 10.2, responses to <faxplay> and <faxrecord> requests have the additional attributes described inTable 37. Van Dyke, et al. Expires September 1, 2006 [Page 77] Internet-Draft MSCML February 2006 +----------------+---------+-----+----------------------------------+ | Attribute | Default | R/O | Description | +----------------+---------+-----+----------------------------------+ |the list below. o reason| | R |- required, no default value: For requests that do not| | | | |complete immediately, the| | | | |"reason" attribute conveys| | | | |additional information regarding| | | | |why the command completed.| | | | |Possible values are "stopped",| | | | |indicating an explicit or| | | | |implicit <stop> request was| | | | |received, "complete" indicating| | | | |successful completion, even if| | | | |there were bad lines or minor| | | | |negotiation problems (e.g. a DCN| | | | |was received), "disconnect"| | | | |meaning that the session was| | | | |disconnected and "notfax"| | | | |indicationg that no DIS or DCS| | | | |was received on the connection.| |o pages_received| | O* |- required (see note), no defaut value: Indicates the number of fax| | | | |pages received.*RequiredNote: This attribute is required if any| | | | |pages were received.| |o pages_sent| | O* |- required (see note), no default value: Indicates the number of fax| | | | |pages sent.*RequiredNote: This attribute is required if any| | | | |pages were sent.| |Van Dyke, et al. Expires November 27, 2006 [Page 54] Internet-Draft MSCML May 2006 o faxcode| | R |- required, no default value: The value of the "faxcode"| | | | |attribute is the binary-or of| | | | |the bit patterns defined in| | | | |Table38. | +----------------+---------+-----+----------------------------------+ Table 37: MSCML Response Attributes for <faxplay> and <faxrecord> Van Dyke, et al. Expires September 1, 2006 [Page 78] Internet-Draft MSCML February 20066. +------+--------------------------------------+ | Mask | description | +------+--------------------------------------+ | 0 | Operation Failed | | 1 | Operation Succeeded | | 2 | Partial Success | | 4 | Image received and placed in recurl | | 8 | Image sent from specified source URL | | 16 | rmtid did not match | | 32 | Error reading source URL | | 64 | Error writing recurl | | 128 | Negotiation failure on send phase | | 256 | Negotiation failure on receive phase | | 512 | Reserved | | 1024 | Irrecoverable IP packet loss | | 2048 | Line errors in received image | +------+--------------------------------------+ Table38:6: Faxcode Mask Responses to <faxplay> and <faxrecord> requests MAY include an <error_info> element as described in Section 10.4.1. 11. Change Summary The changes made between the -07 and -08 versions of the document consisted of formatting changes and other edits which reduced the overall size of the document thereby simplifying the final review and editorial tasks. We believe the -08 version has achieved this goal without sacrificing any important details. No changes were made to the protocol. 12. Formal Syntax The following syntax specification uses XML Schema as described in XML [7].11.1.12.1. Schema <?xml version="1.0" encoding="UTF-8"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"> <xs:element name="MediaServerControl"> Van Dyke, et al. Expires November 27, 2006 [Page 55] Internet-Draft MSCML May 2006 <xs:complexType> <xs:choice> <xs:element name="request"> <xs:complexType> <xs:choice> <xs:element name="configure_conference" type="configure_conferenceRequestType"/> <xs:element name="configure_leg" type="configure_legRequestType"/> <xs:element name="play" type="playRequestType"/> <xs:element name="playcollect" type="playcollectRequestType"/> <xs:element name="playrecord"Van Dyke, et al. Expires September 1, 2006 [Page 79] Internet-Draft MSCML February 2006type="playrecordRequestType"/> <xs:element name="managecontent" type="managecontentRequestType"/> <xs:element name="faxplay" type="faxRequestType"/> <xs:element name="faxrecord" type="faxRequestType"/> <xs:element name="stop" type="stopRequestType"/> </xs:choice> </xs:complexType> </xs:element> <xs:element name="response" type="responseType"/> <xs:element name="notification"> <xs:complexType> <xs:choice> <xs:element name="conference" type="conferenceNotificationType"/> <xs:element name="keypress" type="keypressNotificationType"/> <xs:element name="signal" type="signalNotificationType"/> </xs:choice> </xs:complexType> </xs:element> </xs:choice> <xs:attribute name="version" use="required"/> </xs:complexType> </xs:element> <!-- Definitions for base and concrete MSCML requests --> <!-- and embedded types. --> <xs:complexType name="base_requestType" abstract="true"> <xs:attribute name="id" type="xs:string"/> </xs:complexType> <xs:complexType name="playRequestType"> <xs:complexContent> Van Dyke, et al. Expires November 27, 2006 [Page 56] Internet-Draft MSCML May 2006 <xs:extension base="base_requestType"> <xs:sequence> <xs:element name="prompt" type="promptType" minOccurs="0"/> </xs:sequence> <xs:attribute name="prompturl" type="xs:string"/> <xs:attribute name="offset" type="xs:string"/> <xs:attribute name="promptencoding" type="xs:string"/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="configure_conferenceRequestType"> <xs:complexContent>Van Dyke, et al. Expires September 1, 2006 [Page 80] Internet-Draft MSCML February 2006<xs:extension base="base_requestType"> <xs:sequence> <xs:element name="subscribe" type="conference_eventsubscriptionType" minOccurs="0"/> </xs:sequence> <xs:attribute name="reservedtalkers" type="xs:positiveInteger"/> <xs:attribute name="reserveconfmedia" type="yesnoType" default="yes"/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="configure_legRequestType"> <xs:complexContent> <xs:extension base="base_requestType"> <xs:sequence> <xs:element name="inputgain" type="gainType" minOccurs="0"/> <xs:element name="outputgain" type="gainType" minOccurs="0"/> <xs:element name="configure_team" type="configure_teamType" minOccurs="0"/> <xs:element name="subscribe" type="leg_eventsubscriptionType" minOccurs="0"/> </xs:sequence> <xs:attribute name="type"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="talker"/> <xs:enumeration value="listener"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="mixmode"> <xs:simpleType> Van Dyke, et al. Expires November 27, 2006 [Page 57] Internet-Draft MSCML May 2006 <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="full"/> <xs:enumeration value="mute"/> <xs:enumeration value="preferred"/> <xs:enumeration value="parked"/> <xs:enumeration value="private"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="dtmfclamp" type="yesnoType"/> <xs:attribute name="toneclamp" type="yesnoType"/> </xs:extension> </xs:complexContent>Van Dyke, et al. Expires September 1, 2006 [Page 81] Internet-Draft MSCML February 2006</xs:complexType> <xs:complexType name="configure_teamType"> <xs:sequence> <xs:element name="teammate" type="teammateType" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> <xs:attribute name="id" type="xs:string"/> <xs:attribute name="action" use="required"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:enumeration value="add"/> <xs:enumeration value="delete"/> <xs:enumeration value="query"/> <xs:enumeration value="set"/> </xs:restriction> </xs:simpleType> </xs:attribute> </xs:complexType> <xs:complexType name="teammateType"> <xs:attribute name="id" type="xs:string" use="required"/> </xs:complexType> <xs:complexType name="playcollectRequestType"> <xs:complexContent> <xs:extension base="base_requestType"> <xs:sequence> <xs:element name="prompt" type="promptType" minOccurs="0"/> <xs:element name="pattern" type="dtmfGrammarType" minOccurs="0"/> </xs:sequence> <xs:attribute name="prompturl" type="xs:string"/> <xs:attribute name="offset" type="xs:string"/> <xs:attribute name="barge" type="yesnoType" default="yes"/> <xs:attribute name="promptencoding" type="xs:string"/> <xs:attribute name="cleardigits" type="yesnoType" Van Dyke, et al. Expires November 27, 2006 [Page 58] Internet-Draft MSCML May 2006 default="no"/> <xs:attribute name="maxdigits" type="xs:string"/> <xs:attribute name="firstdigittimer" type="xs:string" default="5000ms"/> <xs:attribute name="interdigittimer" type="xs:string" default="2000ms"/> <xs:attribute name="extradigittimer" type="xs:string" default="1000ms"/> <xs:attribute name="interdigitcriticaltimer" type="xs:string"/> <xs:attribute name="skipinterval" type="xs:string" default="6s"/> <xs:attribute name="ffkey" type="DTMFkeyType"/>Van Dyke, et al. Expires September 1, 2006 [Page 82] Internet-Draft MSCML February 2006<xs:attribute name="rwkey" type="DTMFkeyType"/> <xs:attribute name="returnkey" type="DTMFkeyType" default="#"/> <xs:attribute name="escapekey" type="DTMFkeyType" default="*"/> <xs:attribute name="maskdigits" type="yesnoType" default="no"/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="playrecordRequestType"> <xs:complexContent> <xs:extension base="base_requestType"> <xs:sequence> <xs:element name="prompt" type="promptType" minOccurs="0"/> </xs:sequence> <xs:attribute name="prompturl" type="xs:string"/> <xs:attribute name="promptencoding" type="xs:string"/> <xs:attribute name="offset" type="xs:string" default="0"/> <xs:attribute name="barge" type="yesnoType" default="yes"/> <xs:attribute name="cleardigits" type="yesnoType" default="no"/> <xs:attribute name="escapekey" type="xs:string" default="*"/> <xs:attribute name="recurl" type="xs:string" use="required"/> <xs:attribute name="mode" default="overwrite"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="append"/> <xs:enumeration value="overwrite"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="recencoding" type="xs:string"/> <xs:attribute name="initsilence" type="xs:string"/> Van Dyke, et al. Expires November 27, 2006 [Page 59] Internet-Draft MSCML May 2006 <xs:attribute name="endsilence" type="xs:string"/> <xs:attribute name="duration" type="xs:string"/> <xs:attribute name="beep" type="yesnoType" default="yes"/> <xs:attribute name="recstopmask" type="xs:string" default="01234567890*#"/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="managecontentRequestType"> <xs:complexContent> <xs:extension base="base_requestType"> <xs:attribute name="fetchtimeout" type="xs:string" default="10000"/>Van Dyke, et al. Expires September 1, 2006 [Page 83] Internet-Draft MSCML February 2006<xs:attribute name="mimetype" type="xs:string"/> <xs:attribute name="name" type="xs:string"/> <xs:attribute name="httpmethod"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="put"/> <xs:enumeration value="post"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="action"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="move"/> <xs:enumeration value="delete"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="dest" type="xs:string"/> <xs:attribute name="src" type="xs:string" use="required"/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="stopRequestType"> <xs:complexContent> <xs:extension base="base_requestType"/> </xs:complexContent> </xs:complexType> <xs:complexType name="faxRequestType"> <xs:complexContent> <xs:extension base="base_requestType"> <xs:sequence> <xs:element name="prompt" type="promptType" minOccurs="0"/> </xs:sequence> <xs:attribute name="lclid" type="xs:string"/> Van Dyke, et al. Expires November 27, 2006 [Page 60] Internet-Draft MSCML May 2006 <xs:attribute name="prompturl" type="xs:string"/> <xs:attribute name="recurl" type="xs:string"/> <xs:attribute name="rmtid" type="xs:string"/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="dtmfGrammarType"> <xs:choice> <xs:element name="regex" type="dtmfPatternType" maxOccurs="unbounded"/> <xs:element name="mgcpdigitmap" type="dtmfPatternType"/> <xs:element name="megacodigitmap" type="dtmfPatternType"/> </xs:choice>Van Dyke, et al. Expires September 1, 2006 [Page 84] Internet-Draft MSCML February 2006</xs:complexType> <xs:complexType name="dtmfPatternType"> <xs:attribute name="value" type="xs:string" use="required"/> <xs:attribute name="name" type="xs:string"/> </xs:complexType> <!-- Definitions for base and concrete MSCML responses --> <!-- and embedded types. --> <xs:complexType name="base_responseType" abstract="true"> <xs:attribute name="request" use="required"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="configure_conference"/> <xs:enumeration value="configure_leg"/> <xs:enumeration value="play"/> <xs:enumeration value="playcollect"/> <xs:enumeration value="playrecord"/> <xs:enumeration value="managecontent"/> <xs:enumeration value="faxplay"/> <xs:enumeration value="faxrecord"/> <xs:enumeration value="stop"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="id" type="xs:string"/> <xs:attribute name="code" type="xs:string" use="required"/> <xs:attribute name="text" type="xs:string" use="required"/> </xs:complexType> <xs:complexType name="responseType"> <xs:complexContent> <xs:extension base="base_responseType"> <xs:sequence> <xs:element name="error_info" type="stoponerrorResponseType" minOccurs="0"/> <xs:element name="team" type="configure_teamResponseType" minOccurs="0"/> Van Dyke, et al. Expires November 27, 2006 [Page 61] Internet-Draft MSCML May 2006 </xs:sequence> <xs:attribute name="reason" type="xs:string"/> <xs:attribute name="reclength" type="xs:string"/> <xs:attribute name="recduration" type="xs:string"/> <xs:attribute name="digits" type="xs:string"/> <xs:attribute name="name" type="xs:string"/> <xs:attribute name="playduration" type="xs:string"/> <xs:attribute name="playoffset" type="xs:string"/> <xs:attribute name="faxcode" type="xs:string"/> <xs:attribute name="pages_sent" type="xs:string"/> <xs:attribute name="pages_recv" type="xs:string"/> </xs:extension> </xs:complexContent>Van Dyke, et al. Expires September 1, 2006 [Page 85] Internet-Draft MSCML February 2006</xs:complexType> <xs:complexType name="stoponerrorResponseType"> <xs:attribute name="code" type="xs:string" use="required"/> <xs:attribute name="text" type="xs:string" use="required"/> <xs:attribute name="context" type="xs:string" use="required"/> </xs:complexType> <xs:complexType name="configure_teamResponseType"> <xs:sequence> <xs:element name="teammate" type="teammateType" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> <xs:attribute name="id" type="xs:string" use="required"/> <xs:attribute name="numteam" type="xs:integer" use="required"/> </xs:complexType> <!-- Definitions for MSCML event subscriptions and --> <!-- embedded types --> <xs:complexType name="conference_eventsubscriptionType"> <xs:sequence> <xs:element name="events"> <xs:complexType> <xs:sequence> <xs:element name="activetalkers" type="activetalkersSubscriptionType"/> </xs:sequence> </xs:complexType> </xs:element> </xs:sequence> </xs:complexType> <xs:complexType name="activetalkersSubscriptionType"> <xs:attribute name="report" type="yesnoType" use="required"/> <xs:attribute name="interval" type="xs:string" default="60s"/> </xs:complexType> <xs:complexType name="leg_eventsubscriptionType"> <xs:sequence> <xs:element name="events"> Van Dyke, et al. Expires November 27, 2006 [Page 62] Internet-Draft MSCML May 2006 <xs:complexType> <xs:sequence> <xs:element name="keypress" type="keypressSubscriptionType" minOccurs="0" maxOccurs="1"/> <xs:element name="signal" type="signalSubscriptionType" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> </xs:complexType> </xs:element> </xs:sequence> </xs:complexType> <xs:complexType name="keypressSubscriptionType">Van Dyke, et al. Expires September 1, 2006 [Page 86] Internet-Draft MSCML February 2006<xs:attribute name="report" use="required"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="standard"/> <xs:enumeration value="long"/> <xs:enumeration value="both"/> <xs:enumeration value="none"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="maskdigits" type="yesnoType" default="no"/> </xs:complexType> <xs:complexType name="signalSubscriptionType"> <xs:attribute name="type" type="xs:NMTOKEN" use="required"/> <xs:attribute name="report" type="yesnoType" use="required"/> </xs:complexType> <!-- Definitions for MSCML event notifications and --> <!-- embedded types. --> <xs:complexType name="conferenceNotificationType"> <xs:sequence> <xs:element name="activetalkers" type="activetalkersNotificationType" minOccurs="0"/> </xs:sequence> <xs:attribute name="uniqueid" type="xs:string" use="required"/> <xs:attribute name="numtalkers" type="xs:string" use="required"/> </xs:complexType> <xs:complexType name="activetalkersNotificationType"> <xs:sequence minOccurs="0"> <xs:element name="talker" maxOccurs="unbounded"> <xs:complexType> <xs:attribute name="callid" type="xs:string" use="required"/> </xs:complexType> </xs:element> Van Dyke, et al. Expires November 27, 2006 [Page 63] Internet-Draft MSCML May 2006 </xs:sequence> </xs:complexType> <xs:complexType name="keypressNotificationType"> <xs:sequence> <xs:element name="status" type="statusType"/> </xs:sequence> <xs:attribute name="digit" type="DTMFkeyType" use="required"/> <xs:attribute name="length" use="required"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="standard"/> <xs:enumeration value="long"/> </xs:restriction>Van Dyke, et al. Expires September 1, 2006 [Page 87] Internet-Draft MSCML February 2006</xs:simpleType> </xs:attribute> <xs:attribute name="method" use="required"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="standard"/> <xs:enumeration value="long"/> <xs:enumeration value="double"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="interdigittime" type="xs:string" use="required"/> </xs:complexType> <xs:complexType name="statusType"> <xs:attribute name="command" use="required"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:enumeration value="idle"/> <xs:enumeration value="play"/> <xs:enumeration value="collect"/> <xs:enumeration value="record"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="duration" type="xs:string" use="required"/> </xs:complexType> <xs:complexType name="signalNotificationType"> <xs:attribute name="type" use="required" fixed="busy"/> </xs:complexType> <!-- Definitions for miscellaneous embedded, helper data types --> <xs:complexType name="promptType"> <xs:choice maxOccurs="unbounded"> <xs:element name="audio" type="promptcontentType"/> <xs:element name="variable" type="spokenvariableType"/> Van Dyke, et al. Expires November 27, 2006 [Page 64] Internet-Draft MSCML May 2006 </xs:choice> <xs:attribute name="locale" type="xs:string"/> <xs:attribute name="baseurl" type="xs:string"/> <xs:attribute name="stoponerror" type="yesnoType" default="no"/> <xs:attribute name="gain" type="xs:string" default="0"/> <xs:attribute name="gaindelta" type="xs:string" default="0"/> <xs:attribute name="rate" type="xs:string" default="0"/> <xs:attribute name="ratedelta" type="xs:string" default="0"/> <xs:attribute name="repeat" type="xs:string" default="1"/> <xs:attribute name="duration" type="xs:string" default="infinite"/> <xs:attribute name="offset" type="xs:string" default="0"/> <xs:attribute name="delay" type="xs:string" default="0"/>Van Dyke, et al. Expires September 1, 2006 [Page 88] Internet-Draft MSCML February 2006</xs:complexType> <xs:complexType name="promptcontentType"> <xs:attribute name="url" type="xs:string" use="required"/> <xs:attribute name="encoding" type="xs:string"/> <xs:attribute name="gain" type="xs:string" default="0"/> <xs:attribute name="gaindelta" type="xs:string" default="0"/> <xs:attribute name="rate" type="xs:string" default="0"/> <xs:attribute name="ratedelta" type="xs:string" default="0"/> </xs:complexType> <xs:complexType name="spokenvariableType"> <xs:attribute name="type" use="required"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="dat"/> <xs:enumeration value="dig"/> <xs:enumeration value="dur"/> <xs:enumeration value="mth"/> <xs:enumeration value="mny"/> <xs:enumeration value="num"/> <xs:enumeration value="sil"/> <xs:enumeration value="str"/> <xs:enumeration value="tme"/> <xs:enumeration value="wkd"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="subtype"> <xs:simpleType> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="mdy"/> <xs:enumeration value="dmy"/> <xs:enumeration value="ymd"/> <xs:enumeration value="ndn"/> <xs:enumeration value="t12"/> <xs:enumeration value="t24"/> Van Dyke, et al. Expires November 27, 2006 [Page 65] Internet-Draft MSCML May 2006 <xs:enumeration value="USD"/> <xs:enumeration value="gen"/> <xs:enumeration value="ndn"/> <xs:enumeration value="crd"/> <xs:enumeration value="ord"/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name="value" type="xs:string" use="required"/> </xs:complexType> <xs:simpleType name="yesnoType"> <xs:restriction base="xs:NMTOKEN"> <xs:enumeration value="yes"/>Van Dyke, et al. Expires September 1, 2006 [Page 89] Internet-Draft MSCML February 2006<xs:enumeration value="no"/> <xs:enumeration value="1"/> <xs:enumeration value="0"/> <xs:enumeration value="true"/> <xs:enumeration value="false"/> </xs:restriction> </xs:simpleType> <xs:simpleType name="DTMFkeyType"> <xs:restriction base="xs:string"> <xs:pattern value="[0-9]"/> <xs:pattern value="[A-D]"/> <xs:pattern value="[a-d]"/> <xs:pattern value="#"/> <xs:pattern value="\*"/> </xs:restriction> </xs:simpleType> <xs:complexType name="gainType"> <xs:choice> <xs:element name="auto" type="autogainType"/> <xs:element name="fixed" type="fixedgainType"/> </xs:choice> </xs:complexType> <xs:complexType name="autogainType"> <xs:attribute name="startlevel" type="xs:string"/> <xs:attribute name="targetlevel" type="xs:string"/> <xs:attribute name="silencethreshold" type="xs:string"/> </xs:complexType> <xs:complexType name="fixedgainType"> <xs:attribute name="level" type="xs:string"/> </xs:complexType> </xs:schema>12.Van Dyke, et al. Expires November 27, 2006 [Page 66] Internet-Draft MSCML May 2006 13. IANA Considerations12.1.13.1. IANA Registration of MIME media type application/ mediaservercontrol+xml MIME media type name: application MIME subtype name: mediaservercontrol+xml Required parameters: none Optional parameters: charset charset This parameter has identical semantics to the charset parameter of the "application/xml" media type as specified in XML Media Types [8].Van Dyke, et al. Expires September 1, 2006 [Page 90] Internet-Draft MSCML February 2006Encoding considerations: See RFC3023 [8]. Interoperability considerations: See RFC2023 [8] and RFCXXXX. Published specification: RFCXXXX Applications which use this media type: Multimedia, enhanced conferencing and interactive applications. Personal and email address for further information: eburger@brooktrout.com [29] Intended usage: COMMON13.14. Security Considerations Because media flows through a media server in a conference, the media server itself MUST protect the integrity, confidentiality, and security of the sessions. It should not be possible for a conference participant, on her own behalf, to be able to "tap in" to another conference without proper authorization. Because conferencing is a high value application, the media server SHOULD implement appropriate security measures. This includes, but not limited to, access lists for application servers. That is, the media server only allows a select list of application or proxy servers to create conferences, invite participants to sessions, etc. Note that the mechanisms for such security, like private networks, shared certificates, MAC white/black lists, are beyond the scope of this document. Security concerns are one important reason MSCML limits requests with conference scope to a separate control leg per conference. MSCML uses the simple, proven, Internet-scale security model of SIP to determine if a client is who they say they are (authentication) and if they are allowed to create and manipulate a conference. However, the security model to enable a control leg to manipulate arbitrary conferences on the media server is extremely difficult. One would need to not only authenticate and authorize the basic conference Van Dyke, et al. Expires November 27, 2006 [Page 67] Internet-Draft MSCML May 2006 primitives, but privacy considerations require policies for one client to access another client's conferences, even if the two clients are on the same host. For example, if the media server allowed any control leg to control any conference, an authorized, but unrelated client could maliciously attach itself to an existing session and record or tap the conversation without the participant's knowledge or consent. Participants give implicit authorization to their applications by virtue of the INVITE to the application. However, there is no trust, explicit or implicit, between the users of one service and a distinct client of another service.Van Dyke, et al. Expires September 1, 2006 [Page 91] Internet-Draft MSCML February 2006Because of the sensitive nature of collected data, such as credit card numbers or other identifying information, the media server MUST support sips: and TLS. Clients, who presumably know the value of the information they collect, as well as the privacy expectations of their users, are free to use clear text signaling or encrypted, secure signaling, depending on the application's needs. Likewise, the media server SHOULD support SRTP [9]. Again, the clients are free to negotiate the appropriate level of media security. All MSCML messages are sent within an INVITE created SIP dialog. As a result it would be difficult for an entity other than the original requestor to interfere with an established MSCML session, as this would require detailed information on the dialog state. This allows multiple applications to simultaneously utilize the resources of a single media server without interfering with one another. As an XML markup, all of the security considerations of RFC3023 [8] apply.14.15. References14.1.15.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Burger, E., Van Dyke, J., and A. Spitzer, "Basic Network Media Services with SIP", RFC 4240, December 2005. [3] Donovan, S., "The SIP INFO Method", RFC 2976, October 2000. [4] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. Van Dyke, et al. Expires November 27, 2006 [Page 68] Internet-Draft MSCML May 2006 [5] "Network call signalling protocol for the delivery of time- critical services over cable television networks using cable modems", ITU-T J.162, March 2001. [6] Groves, C., Pantaleo, M., Anderson, T., and T. Taylor, "Gateway Control Protocol Version 1", RFC 3525, June 2003. [7] Thompson, H., Beech, D., Maloney, M., and N. Mendelsohn, "XML Schema Part 1: Structures", W3C REC REC-xmlschema-1-20010502, May 2001. [8] Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types",Van Dyke, et al. Expires September 1, 2006 [Page 92] Internet-Draft MSCML February 2006RFC 3023, January 2001. [9] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, "The Secure Real-time Transport Protocol (SRTP)", RFC 3711, March 2004.14.2.15.2. Informative References [10] Levin, O., "Session Initiation Protocol Call Control - Conferencing for User Agents", draft-ietf-sipping-cc-conferencing-07 (work in progress), June 2005. [11] Carter, J., Danielsen, P., Hunt, A., Ferrans, J., Lucas, B., Porter, B., Rehor, K., Tryphonas, S., McGlashan, S., and D. Burnett, "Voice Extensible Markup Language (VoiceXML) Version 2.0", W3C REC REC-voicexml20-20040316, March 2004. [12] International Packet Communications Consortium, "IPCC Reference Architecture V2", June 2002. [13] European Telecommunications Standards Institute, "Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); IP Multimedia Subsystem (IMS); Stage 2 (3GPP TS 23.228 version 7.2.0 Release 7)", December 2005. [14] Hollenbeck, S., Rose, M., and L. Masinter, "Guidelines for the Use of Extensible Markup Language (XML) within IETF Protocols", BCP 70, RFC 3470, January 2003. [15] Jacobs, I., Lie, H., Bos, B., and C. Lilley, "Cascading Style Sheets, level 2 (CSS2) Specification", W3C REC REC-CSS2- 19980512, May 1998. [16] Rosenberg, J., "A Session Initiation Protocol (SIP) Event Van Dyke, et al. Expires November 27, 2006 [Page 69] Internet-Draft MSCML May 2006 Package for Conference State", draft-ietf-sipping-conference-package-12 (work in progress), July 2005. [17] Cable Television Laboratories, Inc., "Audio Server Protocol", January 2005. [18] "Procedures for document facsimile transmission in the general switched telephone network", Recommendation T.30, April 1999. [19] "Procedures for real-time Group 3 facsimile communication over IP networks", Recommendation T.38, March 2002.Van Dyke, et al. Expires September 1, 2006 [Page 93] Internet-Draft MSCML February 2006[20] Institute of Electrical and Electronics Engineers, "Information Technology - Portable Operating System Interface (POSIX) - Part 1: Base Definitions, Chapter 9", IEEE Standard 1003.1, June 2001. [21] Burger, E. and M. Dolly, "Keypad Stimulus Protocol (KPML)", draft-IETF-sipping-kpml-07 (work in progress), December 2004. [22] Klensin, J., "Simple Mail Transfer Protocol", RFC 2821, April 2001. [23] Campbell, B., "The Message Session Relay Protocol", draft-ietf-simple-message-sessions-09 (work in progress), October 2004. URIs [24] <http://www.ietf.org/html.charters/sip-charter.html> [25] <http://www.ietf.org/html.charters/sipping-charter.html> [26] <http://www.ietf.org/html.charters/mmusic.html> [27] <http://www.ietf.org/html.charters/xcon.html> [28] <http://www.3gpp.org/ftp/Specs/html-info/23228.htm> [29] <mailto:eburger@brooktrout.com> Appendix A. Regex Grammar Syntax The regular expression syntax used in MSCML is a telephony-oriented subset of POSIX Extended Regular Expressions (ERE) [20] termed Digit REGular EXpression (DRegex). This syntax was first described in KPML Van Dyke, et al. Expires November 27, 2006 [Page 70] Internet-Draft MSCML May 2006 [21]. DRegex includes ordinary characters, special characters, bracket expressions and interval expressions. These entities are defined in the list below. character matches digits 0-9, *, #, and A-D (case insensitive) * matches the * character # matches the # characterVan Dyke, et al. Expires September 1, 2006 [Page 94] Internet-Draft MSCML February 2006[character selector] matches any character in selector [range1-range2] matches any character in range from range1 to range2, inclusive x matches any digit 0-9 {m} matches m repetitions of the previous pattern {m,} matches m or more repetitions of the previous pattern {,n} matches at most n (including zero) repetitions of the previous pattern {m,n} at least m and at most n repetitions of the previous pattern L the presence of 'L' in any regex expression causes the Media Server to enable "long" digit detection mode. See Section 7.1 for the definition of "long" digits. Table397 illustrates DRegex usage through examples. +--------------+--------------------------------------------+ | Example | Description | +--------------+--------------------------------------------+ | 1 | Matches the digit 1 | | [179] | Matches 1, 7, or 9 | | [2-9] | Matches 2, 3, 4, 5, 6, 7, 8, 9 | | [02-46-9A-D] | Matches 0, 2, 3, 4, 6, 7, 8, 9, A, B, C, D | | x | Matches 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 | | *6[179#] | Matches *61, *67, *69, or *6# | | x{10} | Ten digits (0-9) | | 011x{7,15} | 011 followed by seven to fifteen digits | | L* | Long star | +--------------+--------------------------------------------+ Table39:7: DRegex Examples Appendix B. Contributors Jeff Van Dyke and Andy Spitzer did the concept, development, documentation, and execution for MSCML at SnowShore Networks, Inc., which is now part of Cantata Technology, Inc. Andy Spitzer's orignal work at The Telephone Connection, Inc. influenced the IVR implementation. Mary Ann Leekley implemented the personalized mix Van Dyke, et al. Expires November 27, 2006 [Page 71] Internet-Draft MSCML May 2006 feature and several other enhancements. Cliff Schornak of Commetrex and Jeff Van Dyke developed the facsimile service. Jai Cauvet, Rolando Herrero, Srinivas Motamarri and Ashish Patel contributed greatly by testing MSCML.Van Dyke, et al. Expires September 1, 2006 [Page 95] Internet-Draft MSCML February 2006Appendix C. Acknowledgements The following individuals significantly assisted in the development, direction, or, most importantly, debugging of MSCML: o Brian Badger and Phil Crable from Verizon Business o Stephane Bastien from BroadSoft o Peter Danielsen of Lucent Technologies o Kevin Flemming formerly of SnowShore Networks, Inc. o Wesley Hicks and Ravindra Kabre, formerly from Sonus Networks o Jon Hinckley from SkyWave/Sestro o Terence Lobo formerly of SnowShore Networks, Inc. o Kunal Nawale formerly of SnowShore Networks, Inc. o Edwina Nowicki formerly of SnowShore Networks, Inc. o Diana Rawlins and Sharadha Vijay formerly of WorldCom o Gaurav Srivastva and Subhash Verma from BayPackets o Kevin Summers from Sonus Networks o Tim Wong from at&t The authors would also like to thank Scotty Farber for applying her considerable tecnhnical writing expertise to the documentation of MSCML. Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page96]72] Internet-Draft MSCMLFebruaryMay 2006 Authors' Addresses Jeff Van DykeBrooktroutCantata Technology, Inc. 18 Keewaydin Dr. Salem, NH 03079 USA Email:jvandyke@brooktrout.comjvandyke@cantata.com Eric Burger (editor)BrooktroutCantata Technology, Inc. 18 Keewaydin Dr. Salem, NH 03079 USA Email:eburger@brooktrout.comeburger@cantata.com Andy SpitzerBrooktrout Technology, Inc. 18 Keewaydin Dr. Salem, NH 03079Pingtel Corporation 400 West Cummings Park Woburn, MA 01801 USA Email:woof@brooktrout.comwoof@pingtel.com Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page97]73] Internet-Draft MSCMLFebruaryMay 2006 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Van Dyke, et al. ExpiresSeptember 1,November 27, 2006 [Page98]74] ----