Multiparty Multimedia Session Control (mmusic) Internet Drafts
| Real Time Streaming Protocol 2.0 (RTSP) | |||||||||||||||||
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This memorandum defines RTSP version 2.0 which is a revision of the Proposed Standard RTSP version 1.0 which is defined in RFC 2326. The Real Time Streaming Protocol, or RTSP, is an application-level protocol for control over the delivery of data with real-time properties. RTSP provides an extensible framework to enable controlled, on-demand delivery of real-time data, such as audio and video. Sources of data can include both live data feeds and stored clips. This protocol is intended to control multiple data delivery sessions, provide a means for choosing delivery channels such as UDP, multicast UDP and TCP, and provide a means for choosing delivery mechanisms based upon RTP (RFC 3550). | ||||||||||||||||
| An Network Address Translator (NAT) Traversal mechanism for media controlled by Real-Time Streaming Protocol (RTSP) | |||||||||||||||||
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This document defines a solution for Network Address Translation (NAT) traversal for datagram based media streams setup and controlled with Real-time Streaming Protocol version 2 (RTSP 2.0). It uses Interactive Connectivity Establishment (ICE) adapted to use RTSP as a signalling channel, defining the necessary extra RTSP extensions and procedures. | ||||||||||||||||
| Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer Protocols | |||||||||||||||||
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This document describes a protocol for Network Address Translator (NAT) traversal for UDP-based multimedia sessions established with the offer/answer model. This protocol is called Interactive Connectivity Establishment (ICE). ICE makes use of the Session Traversal Utilities for NAT (STUN) protocol and its extension, Traversal Using Relay NAT (TURN). ICE can be used by any protocol utilizing the offer/answer model, such as the Session Initiation Protocol (SIP). | ||||||||||||||||
| An Extension to the Session Description Protocol (SDP) for Media Loopback | |||||||||||||||||
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The wide deployment of Voice over IP (VoIP), Real-time Text and Video over IP services has introduced new challenges in managing and maintaining voice/real-time Text/video quality, reliability, and overall performance. In particular, media delivery is an area that needs attention. One method of meeting these challenges is monitoring the media delivery performance by looping media back to the transmitter. This is typically referred to as "active monitoring" of services. Media loopback is especially popular in ensuring the quality of transport to the edge of a given VoIP, Real-time Text or Video over IP service. Today in networks that deliver real-time media, short of running 'ping' and 'traceroute' to the edge, service providers are left without the necessary tools to actively monitor, manage, and diagnose quality issues with their service. The extension defined herein adds new SDP media attributes which enables establishment of media sessions where the media is looped back to the transmitter. Such media sessions will serve as monitoring and troubleshooting tools by providing the means for measurement of more advanced VoIP, Real-time Text and Video Over IP performance metrics. | ||||||||||||||||
| Connectivity Preconditions for Session Description Protocol Media Streams | |||||||||||||||||
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This document defines a new connectivity precondition for the Session Description Protocol (SDP) precondition framework. A connectivity precondition can be used to delay session establishment or modification until media stream connectivity has been successfully verified. The method of verification may vary depending on the type of transport used for the media. For unreliable datagram transports such as UDP, verification involves probing the stream with data or control packets. For reliable connection-oriented transports such as TCP, verification can be achieved simply by successful connection establishment or by probing the connection with data or control packets, depending on the situation. | ||||||||||||||||
| TCP Candidates with Interactive Connectivity Establishment (ICE) | |||||||||||||||||
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Interactive Connectivity Establishment (ICE) defines a mechanism for NAT traversal for multimedia communication protocols based on the offer/answer model of session negotiation. ICE works by providing a set of candidate transport addresses for each media stream, which are then validated with peer-to-peer connectivity checks based on Session Traversal Utilities for NAT (STUN). ICE provides a general framework for describing candidates, but only defines UDP-based transport protocols. This specification extends ICE to TCP-based media, including the ability to offer a mix of TCP and UDP-based candidates for a single stream. | ||||||||||||||||
| A Session Description Protocol (SDP) Offer/Answer Mechanism to Enable File Transfer | |||||||||||||||||
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This document provides a mechanism to negotiate the transfer of one or more files between two endpoints by using the Session Description Protocol (SDP) offer/answer model specified in RFC 3264. SDP is extended to describe the attributes of the files to be transferred. The offerer can either describe the files it wants to send, or the files it would like to receive. The answerer can either accept or reject the offer separately for each individual file. The transfer of one or more files is initiated after a successful negotiation. The Message Session Relay Protocol (MSRP) is defined as the default mechanism to actually carry the files between the endpoints. The conventions on how to use MSRP for file transfer are also provided in this document. | ||||||||||||||||
| SDP media capabilities Negotiation | |||||||||||||||||
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Session Description Protocol (SDP) capability negotiation provides a general framework for indicating and negotiating capabilities in SDP. The base framework defines only capabilities for negotiating transport protocols and attributes. In this document, we extend the framework by defining media capabilities that can be used to negotiate media types and their associated parameters. This extension is designed to map easily to existing and future SDP media attributes. | ||||||||||||||||
| Quality of Service (QoS) Mechanism Selection in the Session Description Protocol (SDP) | |||||||||||||||||
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The offer/answer model for SDP assumes that endpoints establish, somehow, the QoS required for the media streams they establish. Endpoints in closed environments typically agree out of band (e.g., using configuration information) which QoS mechanism to use. However, on the Internet, there is more than one QoS service available. Consequently, there is a need for a mechanism to negotiate which QoS mechanism to use for a particular media stream. This document defines such a mechanism. | ||||||||||||||||
| Source-Specific Media Attributes in the Session Description Protocol (SDP) | |||||||||||||||||
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The Session Description Protocol provides mechanisms to describe attributes of multimedia sessions and of individual media streams (e.g., Real-time Transport Protocol (RTP) sessions) within a multimedia session, but does not provide any mechanism to describe individual media sources within a media stream. This document defines a mechanism to describe RTP media sources, identified by their Synchronization Source Identifiers (SSRCs), in SDP, associate attributes with these sources, and express relationships among sources. It also defines several source-level attributes which can be used to describe properties of media sources. | ||||||||||||||||
| Signaling media decoding dependency in Session Description Protocol (SDP) | |||||||||||||||||
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This memo defines semantics that allow for signaling the decoding dependency of different media descriptions with the same media type in the Session Description Protocol (SDP). This is required, for example, if media data is separated and transported in different network streamsas a result of the use of a layered or multiple descriptive media coding process. A new grouping type "DDP" -- decoding dependency -- is defined, to be used in conjunction with RFC 3388 entitled "Grouping of Media Lines in the Session Description Protocol". In addition, an attribute is specified describing the relationship of the media streams in a "DDP" group indicated by media identification attribute(s) and media format description(s). | ||||||||||||||||
| SDP: Session Description Protocol | |||||||||||||||||
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This memo defines the Session Description Protocol (SDP). SDP is intended for describing multimedia sessions for the purposes of session announcement, session invitation, and other forms of multimedia session initiation. | ||||||||||||||||
| Analysis of Middlebox Interactions for Signaling Protocol Communication along the Media Path | |||||||||||||||||
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Middleboxes are defined as any intermediary box performing functions apart from normal, standard functions of an IP router on the data path between a source host and destination host. Two such functions are network address translation and firewalling. When Application Layer Gateways, such as SIP entities, interact with NATs and firewalls, as described in the MIDCOM architecture, then problems may occur in the transport of media traffic when signaling protocol interaction takes place along the media path, as it is the case for recent key exchange proposals (such as DTLS-SRTP). This document highlights problems that may arise. Unfortunately, it is difficult for the end points to detect or predict problematic behavior and to determine whether the media path is reliably available for packet exchange. This document aims to summarize the various sources and effects of NAT and firewall control, the reasons that they exist, and possible means of improving their behavior to allow protocols that rely upon signaling along the media path to operate effectively. | ||||||||||||||||
| The SDP (Session Description Protocol) Grouping Framework | |||||||||||||||||
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This document defines two Session Description Protocol (SDP) attributes: "group" and "mid". They allow to group together several "m" lines for two different purposes: for lip synchronization and for receiving media from a single flow (several media streams) that are encoded in different formats during a particular session, on different ports and host interfaces. | ||||||||||||||||
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Multiparty Multimedia Session Control (mmusic)
Last Modified: 2008-06-24
Additional information is available at tools.ietf.org/wg/mmusic
Chair(s):
Real-time Applications and Infrastructure Area Director(s):
Real-time Applications and Infrastructure Area Advisor:
Mailing Lists:
General Discussion: mmusic@ietf.orgTo Subscribe: mmusic-request@ietf.org
In Body: subscribe your_email_address
Archive: http://www.ietf.org/mail-archive/web/mmusic/index.html
Description of Working Group:
The Multiparty MUltimedia SessIon Control (MMUSIC) Working Group waschartered to develop protocols to support Internet teleconferencing and
multimedia communications. These protocols are now reasonably mature,
and many have received widespread deployments. The group has revised
some of these protocols in the light of implementation experience and
additional demands that have arisen from other WGs (such as AVT, SIP,
and SIPPING). It is focused on using and negotiating mechanisms such
STUN and TURN in order to enable media sessions to traverse Network
Address Translators NATs, and on new means to exchange SDP capabilities.
Multimedia communications protocols use a common platform to express
media and session descriptions: the Session Description Protocol, SDP.
The many uses of SDP have led to (requests for) numerous extensions and
have led to recognition of several flaws in the protocol design, some of
which were addressed in the revision of SDP. In spite of these, it is
widely deployed.
The current aims of the working group include the following:
- To support the establishment of multi-party multimedia sessions across
NATs, MMUSIC will define an Internet Connectivity Establishment
protocol (ICE). This will define several SDP extensions to work with
NATs for media sessions carried over both UDP and TCP.
- Various extensions to SDP will be pursued to remedy the most urgent of
SDP's shortcomings. These will be limited and include adding support
for limited but generic capability negotiations in SDP, defining the
means to select QoS mechanisms to use for a particular media stream,
enabling file transfer via the SDP Offer/Answer model, and support
for
media loopback.
With the exception of these specific items, only extensions within the
existing SDP framework will be done (e.g. registering new codecs and
defining parameters for them, extending SDP to include new address
families).
- to maintain and revise the specification of the Real Time Streaming
Protocol (RTSP), including fixes and clarifications based on
implementation experience. The revised RTSP specification will be
re-issued as a Proposed Standard RFC. We will also document how RTSP
can be used in the presence of NAT boxes.
The MMUSIC work items will be pursued in close coordination with other
IETF WGs including AVT, SIP, SIPPING, SIMPLE, XCON, and BEHAVE, as well
as others where appropriate such as NSIS.
Goals and Milestones:
| Done | Conduct WG Last Call for SAP Internet-Draft | |
| Done | Submit a revised Internet Multimedia Conferencing Architecture I-D. | |
| Done | Submit a revised SIP I-D. | |
| Done | Submit SDP to the IESG for consideration as a Proposed Standard. | |
| Done | Submit SAP Internet-Draft to IESG for publication as an Experimental Protocol. | |
| Done | Conduct WG Last Call for RTSP Internet-Draft. | |
| Done | Submit Internet-Draft on Internet Multimedia Conferencing Architecture. | |
| Done | Submit RTSP to IESG for consideration as a Proposed Standard. | |
| Done | Conduct WG Last Call for SIP Internet-Draft. | |
| Done | Submit SIP Internet-Draft to IESG for consideration as a Proposed Standard. | |
| Done | Conduct WG Last Call for SAP Security Internet-Draft. | |
| Done | Conduct second WG Last Call for SAP. | |
| Done | Submit SAP Internet-Draft to IESG for consideration as a Proposed Standard. | |
| Done | Submit SAP Security Internet-Draft to IESG for consideration as a Proposed Standard. | |
| Done | Submit IPv6 Extensions to SDP for Proposed Standard | |
| Done | Submit SIP's offer/answer use of SDP for Proposed Standard | |
| Done | Submit SDP4NAT for Proposed Standard (Informational?) | |
| Done | Submit SDP source filter extensions for Proposed Standard | |
| Done | Submit draft on SDPng motivations, comparisons with current SDP capabilities. Request charter review on SDPng work from IAB and IESG. | |
| Done | Submit SDP security extension for Proposed Standard | |
| Done | Submit IMG requirements and framework for Informational | |
| Done | Submit revised SDP spec for Proposed (or Draft) Standard | |
| Done | Submit SDP Offer/Answer examples for Informational | |
| Done | Review work on IMGs and update charter accordingly | |
| Done | Submit SDP connection-oriented media draft for Proposed Standard | |
| Done | Submit SDPng transition scenarios for Informational | |
| Done | Submit ICE draft for Proposed Standard | |
| Done | Submit updated SDP Offer/Answer examples draft for Informational | |
| Feb 2008 | Submit SDP Offer/Answer exchange for enabling file transfer as a Proposed Standard | |
| Feb 2008 | Submit QoS Mechanism Selection in SDP as a Proposed Standard | |
| Feb 2008 | Submit SDP Capability Negotiations to Proposed Standard | |
| Mar 2008 | Submit Considerations for using SDP offer/answer with middleboxes for BCP | |
| Mar 2008 | Submit Source-Specific Media Attributes in SDP as Proposed Standard | |
| Mar 2008 | Submit SDP extensions for Media Loopback for Proposed Standard | |
| Apr 2008 | Submit Connectivity Preconditions for SDP Media Streams as Proposed Standard | |
| Sep 2008 | Submit ICE-TCP draft as a Proposed Standard | |
| Sep 2008 | Signaling media decoding dependency in SDP | |
| Nov 2008 | Submit revised RFC for Grouping of Media Lines in SDP | |
| Nov 2008 | SDP extensions for Media Capability Negotiations | |
| Dec 2008 | Submit revised RTSP spec for Proposed or Draft Standard (as appropriate) | |
| Dec 2008 | Submit RTSP NAT considerations draft | |
| Jan 2010 | Submit revised SDP specification to IETF for Proposed Standard |
Internet-Drafts:
Real Time Streaming Protocol 2.0 (RTSP) (535817 bytes)An Network Address Translator (NAT) Traversal mechanism for media controlled by Real-Time Streaming Protocol (RTSP) (58228 bytes)
Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer Protocols (286365 bytes)
An Extension to the Session Description Protocol (SDP) for Media Loopback (73152 bytes)
Connectivity Preconditions for Session Description Protocol Media Streams (40395 bytes)
TCP Candidates with Interactive Connectivity Establishment (ICE) (48204 bytes)
A Session Description Protocol (SDP) Offer/Answer Mechanism to Enable File Transfer (112991 bytes)
SDP media capabilities Negotiation (77189 bytes)
Quality of Service (QoS) Mechanism Selection in the Session Description Protocol (SDP) (19032 bytes)
Source-Specific Media Attributes in the Session Description Protocol (SDP) (44043 bytes)
Signaling media decoding dependency in Session Description Protocol (SDP) (35955 bytes)
SDP: Session Description Protocol (108209 bytes)
Analysis of Middlebox Interactions for Signaling Protocol Communication along the Media Path (45239 bytes)
The SDP (Session Description Protocol) Grouping Framework (41283 bytes)
Request For Comments:
Real Time Streaming Protocol (RTSP) (RFC 2326) (195011 bytes)SDP: Session Description Protocol (RFC 2327) (87096 bytes) obsoleted by RFC 4566/ updated by RFC 3266
SIP: Session Initiation Protocol (RFC 2543) (338861 bytes) obsoleted by RFC 3261,RFC 3262,RFC 3263,RFC 3264,RFC 3265
Session Announcement Protocol (RFC 2974) (40129 bytes)
Conventions for the use of the Session Description Protocol (SDP)for ATM Bearer Connections (RFC 3108) (248037 bytes)
A Message Bus for Local Coordiantion (RFC 3259) (84125 bytes)
Support for IPv6 in SDP (RFC 3266) (8693 bytes) obsoleted by RFC 4566/ updates RFC 2327
An Offer/Answer Model with SDP (RFC 3264) (60854 bytes) obsoletes RFC 2543
Grouping of media lines in Session Description Protocol SDP (RFC 3388) (39365 bytes)
Mapping of Media Streams to Resource Reservation Flows (RFC 3524) (11249 bytes)
RTCP attribute in SDP (RFC 3605) (17270 bytes)
A Transport Independent Bandwidth Modifier for the Session Description Protocol (SDP) (RFC 3890) (49894 bytes)
The Alternative Network Address Types (ANAT) Semantics for the Session Description Protocol (SDP) Grouping Framework (RFC 4091) (12931 bytes)
TCP-Based Media Transport in the Session Description Protocol (SDP) (RFC 4145) (30225 bytes) updated by RFC 4572
Session Description Protocol (SDP) Offer/Answer Examples (RFC 4317) (32262 bytes)
A Framework for the Usage of Internet Media Guides (IMGs) (RFC 4435) (51687 bytes)
Requirements for Internet Media Guides (IMGs) (RFC 4473) (53864 bytes)
SDP: Session Description Protocol (RFC 4566) (108820 bytes) obsoletes RFC 2327,RFC 3266
Connection-Oriented Media Transport over the Transport Layer Security (TLS) Protocol in the Session Description Protocol (SDP) (RFC 4572) (38658 bytes) updates RFC 4145
Session Description Protocol (SDP) Source Filters (RFC 4570) (28601 bytes)
Session Description Protocol Security Descriptions for Media Streams (RFC 4568) (107881 bytes)
Key Management Extensions for Session Description Protocol (SDP) and Real Time Streaming Protocol (RTSP) (RFC 4567) (67693 bytes)
The Session Description Protocol (SDP) Label Attribute (RFC 4574) (13484 bytes)
Session Description Protocol (SDP) Format for Binary Floor Control Protocol (BFCP) Streams (RFC 4583) (24150 bytes)
Forward Error Correction Grouping Semantics in Session Description Protocol (RFC 4756) (12743 bytes)
The Session Description Protocol (SDP) Content Attribute (RFC 4796) (22886 bytes)
Security Preconditions for Session Description Protocol (SDP) Media Streams (RFC 5027) (37229 bytes) updates RFC 3312
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