Session Description Protocol (SDP) Offer/Answer Examples
RFC 4317
| Document | Type | RFC - Informational (December 2005; No errata) | |
|---|---|---|---|
| Authors | Alan Johnston , Robert Sparks | ||
| Last updated | 2013-03-02 | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 4317 (Informational) | |
| Action Holders |
(None)
|
||
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Jon Peterson | ||
| Send notices to | jo@acm.org, csp@csperkins.org | ||
Network Working Group A. Johnston
Request for Comments: 4317 Tello Corporation
Category: Informational R. Sparks
Estacado Systems
December 2005
Session Description Protocol (SDP)
Offer/Answer Examples
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This document gives examples of Session Description Protocol (SDP)
offer/answer exchanges. Examples include codec negotiation and
selection, hold and resume, and addition and deletion of media
streams. The examples show multiple media types, bidirectional,
unidirectional, inactive streams, and dynamic payload types. Common
Third Party Call Control (3pcc) examples are also given.
Johnston & Sparks Informational [Page 1]
RFC 4317 SDP Offer/Answer Examples December 2005
Table of Contents
1. Overview ........................................................3
2. Codec Negotiation and Selection .................................3
2.1. Audio and Video 1 ..........................................3
2.2. Audio and Video 2 ..........................................4
2.3. Audio and Video 3 ..........................................5
2.4. Two Audio Streams ..........................................6
2.5. Audio and Video 4 ..........................................7
2.6. Audio Only 1 ...............................................8
2.7. Audio and Video 5 ..........................................9
2.8. Audio and Video 6 .........................................10
3. Hold and Resume Scenarios ......................................12
3.1. Hold and Unhold 1 .........................................12
3.2. Hold with Two Streams .....................................13
4. Addition and Deletion of Media Streams .........................15
4.1. Second Audio Stream Added .................................15
4.2. Audio, then Video Added ...................................16
4.3. Audio and Video, Then Video Deleted .......................17
5. Third Party Call Control (3pcc) ................................19
5.1. No Media, Then Audio Added ................................19
5.2. Hold and Unhold 2 .........................................20
5.3. Hold and Unhold 3 .........................................21
6. Security Considerations ........................................22
7. Informative References .........................................22
Johnston & Sparks Informational [Page 2]
RFC 4317 SDP Offer/Answer Examples December 2005
1. Overview
This document describes offer/answer examples of Session Description
Protocol (SDP) based on RFC 3264 [1]. The SDP in these examples is
defined by RFC 2327 [2]. The offers and answers are assumed to be
transported using a protocol such as Session Initiation Protocol
(SIP) [3].
Examples include codec negotiation and selection, hold and resume,
and addition and deletion of media streams. The examples show
multiple media types, bidirectional, unidirectional, inactive
streams, and dynamic payload types. Common Third Party Call Control
(3pcc) [5] examples are also given.
The following sections contain examples in which two parties, Alice
and Bob, exchange SDP offers, answers, and, in some cases, additional
offers and answers. Note that the subject line (s=) contains a
single space character.
2. Codec Negotiation and Selection
2.1. Audio and Video 1
This common scenario shows a video and audio session in which
multiple codecs are offered but only one is accepted. As a result of
the exchange shown below, Alice and Bob may send only PCMU audio and
MPV video. Note: Dynamic payload type 97 is used for iLBC codec [6].
[Offer]
v=0
o=alice 2890844526 2890844526 IN IP4 host.atlanta.example.com
s=
c=IN IP4 host.atlanta.example.com
t=0 0
m=audio 49170 RTP/AVP 0 8 97
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:97 iLBC/8000
m=video 51372 RTP/AVP 31 32
a=rtpmap:31 H261/90000
a=rtpmap:32 MPV/90000
Johnston & Sparks Informational [Page 3]
RFC 4317 SDP Offer/Answer Examples December 2005
[Answer]
v=0
o=bob 2808844564 2808844564 IN IP4 host.biloxi.example.com
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