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Grouping of Media Lines in the Session Description Protocol (SDP) (RFC3388)

IP.com Disclosure Number: IPCOM000010588D
Original Publication Date: 2002-Dec-01
Included in the Prior Art Database: 2002-Dec-20
Document File: 22 page(s) / 40K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

G. Camarillo: AUTHOR [+4]

Abstract

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.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 7% of the total text.

Network Working Group                                       G. Camarillo

Request for Comments: 3388                                   G. Eriksson

Category: Standards Track                                      J. Holler

                                                                Ericsson

                                                          H. Schulzrinne

                                                     Columbia University

                                                           December 2002

   Grouping of Media Lines in the Session Description Protocol (SDP)

Status of this Memo

   This document specifies an Internet standards track protocol for the

   Internet community, and requests discussion and suggestions for

   improvements.  Please refer to the current edition of the "Internet

   Official Protocol Standards" (STD 1) for the standardization state

   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   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.

Table of Contents

   1. Introduction..................................................  2

   2. Terminology...................................................  2

   3. Media Stream Identification Attribute.........................  3

   4. Group Attribute...............................................  3

   5. Use of "group" and "mid"......................................  3

   6. Lip Synchronization (LS)......................................  4

      6.1 Example of LS.............................................  5

   7. Flow Identification (FID).....................................  5

      7.1 SIP and Cellular Access...................................  6

      7.2 DTMF Tones................................................  6

      7.3 Media Flow Definition.....................................  6

      7.4 FID Semantics.............................................  7

          7.4.1 Examples of FID.....................................  8

      7.5 Scenarios that FID does not Cover........................  11

Camarillo et. al.           Standards Track                     [Page 1]

RFC 3388             Grouping of Media Lin...