One document matched: draft-nandakumar-rtcweb-sdp-01.xml
<?xml version="1.0" encoding="US-ASCII"?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd">
<?xml-stylesheet type="text/xsl" href="rfc2629.xslt" ?>
<?rfc toc="yes" ?>
<?rfc symrefs="yes" ?>
<?rfc iprnotified="yes" ?>
<?rfc strict="no" ?>
<?rfc compact="yes" ?>
<?rfc sortrefs="no" ?>
<?rfc colonspace="yes" ?>
<?rfc rfcedstyle="no" ?>
<?rfc tocdepth="4"?>
<rfc category="info" docName="draft-nandakumar-rtcweb-sdp-01"
ipr="trust200902">
<front>
<title abbrev="SDP4WebRTC">SDP for the WebRTC</title>
<author fullname="Suhas Nandakumar" initials="S." surname="Nandakumar">
<organization>Cisco</organization>
<address>
<postal>
<street>170 West Tasman Drive</street>
<city>San Jose</city>
<region>CA</region>
<code>95134</code>
<country>USA</country>
</postal>
<email>snandaku@cisco.com</email>
</address>
</author>
<author fullname="Cullen Jennings" initials="C." surname="Jennings">
<organization>Cisco</organization>
<address>
<postal>
<street>170 West Tasman Drive</street>
<city>San Jose</city>
<region>CA</region>
<code>95134</code>
<country>USA</country>
</postal>
<phone>+1 408 421-9990</phone>
<email>fluffy@cisco.com</email>
</address>
</author>
<date day="23" month="February" year="2013" />
<area>RAI</area>
<abstract>
<t>The Web Real-Time Communication (WebRTC) <xref target="WEBRTC"></xref> working group is charged to provide protocol support for
direct interactive rich communication using audio, video and data between two peers' web browsers.
With in the WebRTC framework, Session Description protocol (SDP) <xref target="RFC4566"></xref> is used for negotiating
session capabilities between the peers. Such a negotiataion happens based on the SDP Offer/Answer exchange
mechanism described in the RFC 3264 <xref target="RFC3264"></xref>.
</t>
<t>This document serves a introductory purpose in describing the role of SDP for the most common WebRTC use-cases.
</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>Javascript Session Exchange Protocol(JSEP) <xref target="JSEP"></xref> specifies a generic protocol needed to generate
<xref target="RFC3264"></xref> offers and answers negotiated between the WebRTC peers for setting up,
updating and tearing down a multimedia session. For this purpose, SDP is used to construct <xref target="RFC3264"></xref>
offers/answers for describing (media and non-media) streams as appropriate for recipients
of a session description to participate in the session.
</t>
<t>The remainder of this document is organized as follows: Section 3 and 4 provide an overview of
SDP and the Offer/Answer exchange mechanism. Section 5 and 6 provide sample SDP usages for the most common
WebRTC use-cases.</t>
</section>
<section title="Terminology">
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
"RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
interpreted as described in <xref target="RFC2119"></xref>.</t>
</section>
<section title="SDP and the WebRTC">
<t>
The purpose of this section is to provide a general overview of SDP and its components.
For a more in-depth understanding, the readers are advised to refer to the <xref target="RFC4566"></xref>.
</t>
<t>
The Session Description Protocol (SDP) <xref target="RFC4566"></xref> describes multimedia sessions,which
can be audio,video, whiteboards,fax,modem, and other streams. It provides a general purpose,standard representation
to describe various aspects of multimedia session such as media capabilities,transport addresses and related metadata
in a transport agnostic manner,for the purposes of session announcement,session invitation and parameter negotiation.
</t>
<t>
As of today SDP is widely used in the context of Session Initiation Protocol,Real-time Transport Protocol,
and Real-time Streaming Protocol.
</t>
<t>
Below figure introduces high-level breakup of SDP into components that semantically describe a multimedia session,
in our case,say,a WebRTC session <xref target="WEBRTC"></xref>. It by no means captures everything about SDP and hence, should
be used for informational purposes only.
</t>
<figure>
<artwork alt="Semantic Components of SDP"
src="sdp.png"></artwork>
</figure>
<t>
<xref target="WEBRTC"></xref> proposes JavaScript application to fully control the signaling plane
of a multimedia session as described in the JSEP specification <xref target="JSEP"></xref>. JSEP provides mechanisms to create
session characterisation and media definition information to conduct the session based on SDP exchanges.
</t>
<t>
In this context,SDP serves two purposes:
<list>
<t>Provide grammatical structure syntatically</t>
<t>Semantically convey partipant's intention and capabilities.</t>
</list>
</t>
</section>
<section title="Offer/Answer and the WebRTC">
<t>
This section introduces SDP Offer/Answer Exchange mechanism mandated by WebRTC for negotitating session capabilities
while setting up,updating and tearing down a WebRTC session. This section is intentionally brief in nature and
interested readers are recommended to <xref target="RFC3264"></xref> for specific details on the protocol
operation.
</t>
<t>
The Offer/Answer <xref target="RFC3264"></xref> model specifies rule for the bilateral exchange of Session Description Protocol (SDP)
messages for creation of multimedia streams.It defines protocol with involved participants exchanging desired session characteristics
from each others perspective modelled on SDP to negotiate the session between them.
</t>
<t>
In the most basic form,the protocol operation begins by one of the participants sending an initial SDP offer
describing its intent to start a multimedia communication session. The participant receiving the offer MAY generate
an SDP answer accepting the offer or it MAY reject the offer. If the session is accepted the offer answer model
guarantees a common view of the multimedia session between the participants.
</t>
<t>
At any time, either participant MAY generate a new SDP offer that updates the session in progress.
</t>
<t>
With in the context of WebRTC, the Offer/Answer model defines the state-machinery for WebRTC peers to negotiate session descriptions
between them during initial setup stages as well as for eventual session updates.
Javascript Session Establishment Protocol specification <xref target="JSEP"></xref> for WebRTC provides the mechanism for generating
<xref target="RFC3264"></xref> SDP offers and answers in order for both sides of the session to agree upon
details such as list of media formats to be sent/received, bandwidth information, crypto parameters, transport parameters, for example.
</t>
<t>
The following sections provide samples of SDP message details and exchanges for the most common WebRTC usecases.
</t>
</section>
<section title="WebRTC Session Description Examples">
<t>
A typical web based real-time multimedia communication session can be characterized as below:
</t>
<t>
<list>
<t>It has zero or more Audio only,Video only or Audio/Video Media streams</t>
<t>MAY contain zero or more non-media data streams</t>
<t>All the streams are secured with DTLS/SRTP</t>
<t>ICE processing for NAT Traversal</t>
<t>Sessions over IPv4-only, IPv6-only, dual-stack based clients.</t>
</list>
</t>
<t>
As mentioned earlier <xref target="WEBRTC"></xref> proposes using SDP based Offer/Answer model to negotiate
multimedia session between peers' browsers
Building on the concepts from the previous sections, the following subsections attempts to
describe the usage of SDP for the most common WebRTC use-cases.
</t>
<t>
In all the use-cases, Alice and Bob are assumed to be the WebRTC peers unless mentioned otherwise.
Pointers to appropriate RFCs and notes are provided, wherever necessary,agains the SDP lines.
</t>
<section anchor="successful-2way-savpf"
title="Secure Two-Way Audio,Video and Data with RTCP Feedback">
<t>This use-case allows two users to participate in a two-way communication session securely on their WebRTC enabled
Web browsers.
</t>
<figure>
<artwork alt="Successful-Session 2 Way SAVPF"
src="Two-WaySAVPF.png"><![CDATA[
title WebRTC Session - 2-Way Secure Audio,Video with RTCP Feedback
Alice->Bob: Offer(Audio:G.711,Opus,iLBC Video:H.264,VP8)
Bob->Alice: Answer(Audio:Opus,DTMF Video:H.264)
Alice->Bob: Two-way Opus Audio, H.264 Video
note right of Alice
Session also suports RTP/RTCP Mux, RTCP feedback (nack,pli)
end note
]]></artwork>
</figure>
<t>
More specifically, this use-case demonstrates following aspects of a WebRTC session
<list>
<t>SRTP with DTLS based encryption</t>
<t>RTP and RTCP Muxing</t>
<t>RTCP based feedback and reduced size support</t>
<t>ICE processing for NAT Traversal</t>
<t>Audio Codec Offered : PCMU, Opus, iLBC</t>
<t>Audio Codec Answered : Opus</t>
<t>Video Codecs Offered: H.264, VP8</t>
<t>Video Codecs Answered: H.264</t>
<t>Data Channel Support</t>
</list>
The tables (5.1 and 5.2) below capture in detail, the initial SDP Offer and Answer messages exchanged.
</t>
<t hangText="Authors' Note">
The exact SDP parameters specified for Data-Channel is still under the WG discussion and is
expected to be updated once a decission is made.
</t>
<texttable anchor="table_1_1" title="5.1 SDP Offer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20518 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref> - Session Origin Information</c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref> - Session Level ICE parameter</c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref> - Session Level ICE parameter</c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref> - Session DTLS Fingerprint for SRTP</c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref> - Alice intends to use reduced size RTCP for this session</c>
<c>m=audio 54609 RTP/SAVPF 0 109 98</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:0 PCMU/8000</c>
<c><xref target="RFC3551"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=rtpmap:98 iLBC/8000
a=fmtp:98 mode=20</c>
<c><xref target="RFC3952"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref> - Alice can send and recv audio</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref> - Alice can perform RTP/RTCP Muxing on port 54609</c>
<c>b=AS:256</c>
<c><xref target="RFC4566"></xref></c>
<c>b=RS:0</c>
<c><xref target="RFC3556"></xref></c>
<c>b=RR:0</c>
<c><xref target="RFC3556"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref> - Host ICE Candidate</c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref> - Server Reflexive ICE Candidate for the above host candidate</c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref> - Second Host Candidate </c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref> -Server Reflexive Candidate for the Second Host Candidate</c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref> - Indicates NACK RTCP feedback support</c>
<c>m=video 62537 RTP/SAVPF 99 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:99 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=fmtp:99 profile-level-id=4d0028;packetization-mode=1</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref> - Alice can send and recv video</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref> - Alice can perform RTP/RTCP Muxing on port 62537</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 62537 typ srflx raddr 192.168.1.4 rport 62537</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 54721 typ srflx raddr 192.168.1.4 rport 54721</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:99 nack pli</c>
<c><xref target="RFC5104"></xref> - Indicates support for Picture loss Indication and NACK</c>
<c>a=rtcp-fb:99 ccm fir</c>
<c><xref target="RFC5104"></xref> - Full Intra Frame Request-Codec Control Message support</c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref> - Indicates support for Picture loss Indication and NACK</c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref> - Full Intra Frame Request-Codec Control Message support</c>
<c>m=application 56966 DTLS/SCTP 5000</c>
<c><xref target="draft-ietf-rtcweb-data-channel"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=sctpmap:5000 webrtc-Datachannel 1</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref> - One data stream of type chat</c>
<c>a=webrtc-Datachannel:5000 stream=1;label="channel 1";subprotocol="chat";</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref> - Alice can send and recv non-media data</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref> - Alice can perform RTP/RTCP Muxing on port 56966</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 56966 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 56966 typ srflx raddr 192.168.1.7 rport 56966</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 51641 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 51641 typ srflx raddr 192.168.1.7 rport 51641</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:5000 nack </c>
<c><xref target="RFC5104"></xref> - Indicates NACK feedback support for the data-channel</c>
</texttable>
<texttable anchor="table_1_2" title="5.1 SDP Answer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref> - Session Origin Information</c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref> - Session Level ICE username frag</c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref> - Session Level ICE password</c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref> - Session DTLS Fingerprint for SRTP</c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref> - Alice intends to use reduced size RTCP for this session</c>
<c>m=audio 49203 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref> - Bob can send and recv audio</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref> - Bob can perform RTP/RTCP Muxing on port 49203</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref> - Host ICE Candidate for Opus Stream</c>
<c>a=ccandidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref> - Server Reflexive ICE Candidate for the above host candidate</c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref> - Second Host Candidate </c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref> -Server Reflexive Candidate for the Second Host Candidate</c>
<c>m=video 63130 RTP/SAVPF 99</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:99 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=fmtp:99 profile-level-id=4d0028;packetization-mode=1</c>
<c><xref target="RFC3984"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref> - Bob can send and recv video</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref> - Bob can perform RTP/RTCP Muxing on port 63130</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63130 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 63130 typ srflx raddr 192.168.1.7 rport 63130</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56607 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 56607 typ srflx raddr 192.168.1.7 rport 56607</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:99 nack pli</c>
<c><xref target="RFC5104"></xref> - Indicates support for Picture loss Indication and NACK</c>
<c>a=rtcp-fb:99 ccm fir</c>
<c><xref target="RFC5104"></xref> - Full Intra Frame Request-Codec Control Message support</c>
<c>m=application 55700 DTLS/SCTP 5000</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=sctpmap:5000 webrtc-Datachannel 1</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref></c>
<c>a=webrtc-Datachannel:5000 stream=1;label="channel 1";subprotocol="chat";</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref> - Bob can send and recv non-media data</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref> - Bob can perform RTP/RTCP Muxing on port 55700</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 55700 typ host</c>
<c><xref target="RFC5245"></xref> - Refer 4.1 SDP Offer</c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 55700 typ srflx raddr 192.168.1.7 rport 55700</c>
<c><xref target="RFC5245"></xref> Refer 4.1 SDP Offer</c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 58137 typ host</c>
<c><xref target="RFC5245"></xref> Refer 4.1 SDP Offer</c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 58137 typ srflx raddr 192.168.1.7 rport 581371</c>
<c><xref target="RFC5245"></xref> Refer 4.1 SDP Offer</c>
<c>a=rtcp-fb:5000 nack </c>
<c><xref target="RFC5104"></xref> - Indicates NACK feedback support for the data-channel</c>
</texttable>
</section>
<section anchor="sec.successful-session-remove-datachannel"
title="Secure Two-way Audio,Video,Data and remove data stream">
<t>This scenario builds upon from the usecase in the section 5.1
It extends by Alice removing data-stream once the session is in progress.
</t>
<figure>
<artwork alt="Successful-Session Remove Data"
src="SessionAVD-D.png"><![CDATA[
title WebRTC Session (Audio,Video,Datachannel) - Drop Datachannel
note right of Alice
Alice & Bob are in a two-way audio,video and datachannel session.
Alice decides to stop the datachannel stream
end note
Alice->Bob: Offer(Audio:Opus Video:VP8, Application: Drop)
Bob->Alice: Answer(Audio:Opus Video:VP8, Application:Drop)
Alice->Bob: Two-way Opus Audio and VP8 Video
]]></artwork>
</figure>
<t>
As a precondition, A Two-Way Audio,Video and Data Session is already setup.
</t>
<texttable anchor="table_2_1" title="5.2 SDP Updated Offer w/DataChannel Drop">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20519 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 54609 RTP/SAVPF 0 109 98</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:0 PCMU/8000</c>
<c><xref target="RFC3551"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=rtpmap:98 iLBC/8000
a=fmtp:98 mode=20</c>
<c><xref target="RFC3952"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 62537 RTP/SAVPF 99 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:99 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=fmtp:99 profile-level-id=4d0028;packetization-mode=1</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 62537 typ srflx raddr 192.168.1.4 rport 62537</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 54721 typ srflx raddr 192.168.1.4 rport 54721</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:99 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:99 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
<c>m=application 0 DTLS/SCTP 5000</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref> - Port 0 indicates dropping data stream </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=sctmap:5000 webrtc-Datachannel 1</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref></c>
<c>a=webrtc-Datachannel:5000 stream=1;label="channel 1";subprotocol="chat";</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 56966 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 56966 typ srflx raddr 192.168.1.7 rport 56966</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 51641 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 51641 typ srflx raddr 192.168.1.7 rport 51641</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:5000 nack </c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_2_2" title="5.2 SDP Updated Answer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 49203 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ccandidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 63130 RTP/SAVPF 99 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:99 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=fmtp:99 profile-level-id=4d0028;packetization-mode=1</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63130 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 63130 typ srflx raddr 192.168.1.7 rport 63130</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56607 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 56607 typ srflx raddr 192.168.1.7 rport 56607</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:99 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:99 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
<c>m=application 0 DTLS/SCTP 5000</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref> Bob accepts dropping the data stream </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=sctpmap:5000 webrtc-Datachannel 1</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref></c>
<c>a=webrtc-Datachannel:5000 stream=1;label="channel 1";subprotocol="chat";</c>
<c><xref target="draft-ietf-mmusic-sctp-sdp"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 55700 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 55700 typ srflx raddr 192.168.1.7 rport 55700</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 58137 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 58137 typ srflx raddr 192.168.1.7 rport 581371</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:5000 nack </c>
<c><xref target="RFC5104"></xref></c>
</texttable>
</section>
<section anchor="successful-2way-bundle"
title="Secure Two-Way Audio,Video w/BUNDLE Support Unknown">
<t>This use-case demonstrates a successfull audio and video multiplexing scenario
with SDP BUNDLE negotiation when the Alice is unsure of the Bob's BUNDLE support.
Table below also illustrates, additional SDP Offer/Answer exchange once the Alice
figures that a 2-way BUNDLE session can be setup.
</t>
<figure>
<artwork alt="Successful-Session 2 Way BUNDLE"
src="Two-WayBundle.png"><![CDATA[
title WebRTC Session - 2-Way Secure Audio,Video with BUNDLE
Alice->Bob: Offer(Audio:Opus Video:VP8) with BUNDLE support and different port numbers
Bob->Alice: Answer(Audio:Opus Video:VP8) indicating its support for BUNDLE
Alice->Bob: Updated Offer(Audio:Opus Video:VP8) with BUNDLE support and same port number
Bob->Alice: Answer(Audio:Opus Video:VP8) accepts the updated Offer
Alice->Bob: Two-way Opus Audio, H.264 Video over a single 5-tuple
]]></artwork>
</figure>
<texttable anchor="table_3_1" title="5.3 SDP Offer w/BUNDLE">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20518 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>a=group:BUNDLE foo bar</c>
<c><xref target="draft-ietf-mmusic-sdp-bundle-negotiation"></xref> Alice supports grouping of m=lines</c>
<c>m=audio 54609 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:foo</c>
<c><xref target="RFC5888"></xref> Audio m=line part of BUNDLE group with a unique port number</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 62537 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:bar</c>
<c><xref target="RFC5888"></xref> Video m=line part of the Bundle group with a unique port number</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:1000</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 62537 typ srflx raddr 192.168.1.4 rport 62537</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 54721 typ srflx raddr 192.168.1.4 rport 54721</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_3_2" title="5.3 SDP Answer w/BUNDLE">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>a=group:BUNDLE foo bar</c>
<c><xref target="draft-ietf-mmusic-sdp-bundle-negotiation"></xref> Bob supports grouping of m=lines and indicates his interest in the same as well</c>
<c>m=audio 49203 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:foo</c>
<c><xref target="RFC5888"></xref> Audio m=line part of the BUNDLE group</c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 49203 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>a=mid:bar</c>
<c><xref target="RFC5888"></xref> Video m=line part of the BUNDLE group with the port from audio line repeated </c>
<c>b=AS:1000</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
<texttable anchor="table_3_3" title="5.3 SDP Updated Offer w/Bundle">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20518 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>a=group:BUNDLE foo bar</c>
<c><xref target="draft-ietf-mmusic-sdp-bundle-negotiation"></xref> Alice supports grouping of m=lines</c>
<c>m=audio 54609 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:foo</c>
<c><xref target="RFC5888"></xref> Audio m=line part of BUNDLE group with a unique port number</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 54609 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:bar</c>
<c><xref target="RFC5888"></xref > Video m=line part of the BUNDLE group with port from audio line repeated </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:1000</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_3_4" title="5.3 SDP Answer w/BUNDLE">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>a=group:BUNDLE foo bar</c>
<c><xref target="draft-ietf-mmusic-sdp-bundle-negotiation"></xref> Bob supports grouping of m=lines and indicates his interest in the same as well</c>
<c>m=audio 49203 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:foo</c>
<c><xref target="RFC5888"></xref> Audio m=line part of the BUNDLE group</c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 49203 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>a=mid:bar</c>
<c><xref target="RFC5888"></xref> Video m=line part of the BUNDLE group with the port from audio line repeated </c>
<c>b=AS:1000</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
</section>
<section anchor="successful-2way-bundle-one-exchange"
title="Secure Two-Way Audio,Video w/BUNDLE Support Known">
<t>This use-case demonstrates a successfull audio and video multiplexing scenario
with SDP BUNDLE negotiation Alice (Offerer) knows about Bob's (Answerer) BUNDLE
support.
</t>
<figure>
<artwork alt="Successful-Session 2 Way BUNDLE Support Known"
src="Two-WayBundle_Preknown.png"><![CDATA[
title WebRTC Session - 2-Way Secure Audio,Video with BUNDLE Support Known
Alice->Bob: Offer(Audio:Opus Video:VP8) with identical port numbers
Bob->Alice: Answer(Audio:Opus Video:VP8) with identical port numbers
Alice->Bob: Two-way Opus Audio, H.264 Video over a single 5-tuple
]]></artwork>
</figure>
<texttable anchor="table_4_1" title="5.4 SDP Offer w/BUNDLE">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20518 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>a=group:BUNDLE foo bar</c>
<c><xref target="draft-ietf-mmusic-sdp-bundle-negotiation"></xref> Alice supports grouping of m=lines</c>
<c>m=audio 10000 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:foo</c>
<c><xref target="RFC5888"></xref> Audio m=line part of BUNDLE group with a unique port number</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 10000 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 10000 typ srflx raddr 192.168.1.4 rport 10000</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 10000 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:bar</c>
<c><xref target="RFC5888"></xref> Video m=line part of the BUNDLE group with audio port repeated</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:1000</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 10000 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 10000 typ srflx raddr 192.168.1.4 rport 10000</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_4_2" title="5.4 SDP Answer w/BUNDLE">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>a=group:BUNDLE foo bar</c>
<c><xref target="draft-ietf-mmusic-sdp-bundle-negotiation"></xref> Bob supports grouping of m=lines and indicates his interest in the same as well</c>
<c>m=audio 20000 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:foo</c>
<c><xref target="RFC5888"></xref> Audio m=line part of the BUNDLE group</c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 20000 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 20000 typ srflx raddr 192.168.1.7 rport 20000</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 20000 RTP/SAVPF 120</c>
<c>a=mid:bar</c>
<c><xref target="RFC5888"></xref>Video m=line part of the BUNDLE group with the port from audio line repeated </c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref> </c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 20000 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 20000 typ srflx raddr 192.168.1.7 rport 20000</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
</section>
<section anchor="successful-2way-bundle-unsupported"
title="Secure Two-Way Audio,Video w/BUNDLE Unsupported">
<t> This use-case illustrates SDP Offer/Answer exchange when the far-end (Bob)
either doesn't support media bundling or doesnot want to group m=lines over
a single 5-tuple.
</t>
<figure>
<artwork alt="Successful-Session 2 Way BUNDLE Unsupported"
src="Two-WayBundle_unsupported.png"><![CDATA[
title WebRTC Session - 2-Way Secure Audio,Video with BUNDLE Unsupported
Alice->Bob: Offer(Audio:Opus Video:VP8) with BUNDLE support, unique port numbers
Bob->Alice: Answer(Audio:Opus Video:VP8) with no BUNDLE support, unique port numbers
Alice->Bob: Two-way Opus Audio, H.264 Video over 2 different RTP sessions.
]]></artwork>
</figure>
<texttable anchor="table_5_1" title="5.5 SDP Offer w/BUNDLE">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20518 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>a=group:BUNDLE foo bar</c>
<c><xref target="draft-ietf-mmusic-sdp-bundle-negotiation"></xref> Alice supports grouping of m=lines</c>
<c>m=audio 55232 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:foo</c>
<c><xref target="RFC5888"></xref> Audio m=line part of BUNDLE group with a unique port number</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 55232 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 55232 typ srflx raddr 192.168.1.4 rport 55232</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 54332 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref></c>
<c>a=mid:bar</c>
<c><xref target="RFC5888"></xref> Video m=line part of the BUNDLE group with a unique port number</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:1000</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54332 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 54332 typ srflx raddr 192.168.1.4 rport 54332</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 54721 typ srflx raddr 192.168.1.4 rport 54721</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_5_2" title="5.5 SDP Answer w/BUNDLE">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 53214 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 53214 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 53214 typ srflx raddr 192.168.1.7 rport 53214</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 58679 RTP/SAVPF 120</c>
<c>b=AS:200</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref> </c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 58679 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 58679 typ srflx raddr 192.168.1.7 rport 58679</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56607 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 56607 typ srflx raddr 192.168.1.7 rport 56607</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
</section>
<section anchor="sec.successful-session-two-video-streams"
title="Successful One Way Session with 2 Video Streams">
<t> In this scenario Alice and Bob engage in one-way multimedia session with
Bob receiving two video streams, one corresponding to Alice's video and other corresponding to
her presentation slides.
</t>
<figure>
<artwork alt="Successful-Session 1 Way 2 Video"
src="Session1A2V.png"><![CDATA[
title 1 Way Audio & Video w/2 Video Streams
note right of Alice
Alice offers 2 sendonly video streams
one for her video feed and other for her presentation slides.
end note
Alice->Bob: Offer(Audio:Opus, Video1,2: VP8)
note right of Bob
Bob accepts Alice's offer
end note
Bob->Alice: Answer(Audio:Opus, Video1,2: VP8)
Alice->Bob: One-way Opus Audio, VP8 Video
note right of Alice
Bob can hear Alice and see her video feed as well
as her presentation slides.
end note
]]></artwork>
</figure>
<texttable anchor="table_6_1" title="5.6 SDP Offer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20519 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 54609 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only audio stream</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 62537 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=content:speaker</c>
<c><xref target="RFC4796"></xref> - Stream 1 for Alice's video</c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 62539 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=content:slides</c>
<c><xref target="RFC4796"></xref> - Stream 2 for Alice's slides</c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62539 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54723 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_6_2" title="5.6 SDP Answer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 49203 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Receive only audio stream</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 63130 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=content:speaker</c>
<c><xref target="RFC4796"></xref> - Stream 1 for Alice's Video</c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Receive Only Video Stream 1</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63130 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56607 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 63133 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=content:slides</c>
<c><xref target="RFC4796"></xref> - Stream 2 for Alice's Slides</c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Receive Only Video Stream 2</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63133 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
</section>
<section anchor="sec.successful-session-add-new-media"
title="Add New Media (video)">
<t>This scenario describes the message exchanges when Alice decides
to add video to an existing audio-only session</t>
<figure>
<artwork alt="Successful-Session 2 Way SAVPF"
src="AddVideo.png"><![CDATA[
title Add New Media(Video)
Alice->Bob: Offer(Audio:G.711,Opus,iLBC)
Bob->Alice: Answer(Audio:Opus)
Alice->Bob: Two-way Opus Audio
note right of Alice
Alice decides to add Video
end note
Alice->Bob: Offer(Audio:G.711,Opus,iLBC Video:VP8)
Bob->Alice: Answer(Audio:Opus, Video:VP8)
Alice->Bob: Two-way Opus Audio, VP8 Video
]]></artwork>
</figure>
<texttable anchor="table_7_1" title="5.7 SDP Initial Audio Only Offer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20519 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 54609 RTP/SAVPF 0 109 98</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:0 PCMU/8000</c>
<c><xref target="RFC3551"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=rtpmap:98 iLBC/8000
a=fmtp:98 mode=20</c>
<c><xref target="RFC3952"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>b=AS:256</c>
<c><xref target="RFC4566"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_7_2" title="5.7 SDP Answer- Audio Only">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 49203 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ccandidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
<t>
Alice decides to add Video to the current session
</t>
<texttable anchor="table_7_3" title="5.7 SDP Updated Offer w/Video">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20520 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref> - Increased Version Number</c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 54609 RTP/SAVPF 0 109 98</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:0 PCMU/8000</c>
<c><xref target="RFC3551"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=rtpmap:98 iLBC/8000
a=fmtp:98 mode=20</c>
<c><xref target="RFC3952"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 62537 RTP/SAVPF120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 62537 typ srflx raddr 192.168.1.4 rport 62537</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 54721 typ srflx raddr 192.168.1.4 rport 54721</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_7_4" title="5.7 SDP Updated Answer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 49203 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ccandidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 63130 RTP/SAVPF 99 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63130 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 63130 typ srflx raddr 192.168.1.7 rport 63130</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56607 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 56607 typ srflx raddr 192.168.1.7 rport 56607</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
</section>
<section anchor="sec.successful-session-simulcast"
title="Successful Simulcast with 2 Encodings, 2 Cameras">
<t> The SDP Offer/Answer exchange illustrates simulcasting use-case, where Alice
2 cameras with 2 encoding options per camera.
</t>
<figure>
<artwork alt="Successful-Session Simulcast"
src="SessionSimulcast.png"><![CDATA[
title 2 Way Successful Simulcast
note right of Alice
Alice offers 2 sendonly video streams with 2 simulcast encodings per stream
end note
Alice->Bob: Offer(Video1,2: H.264)
note left of Bob
Bob accepts Alice's offer and 1 encoding per stream
end note
Bob->Alice: Answer(Video1,2: H.264)
Alice->Bob: One-Way H.264 Video with Bob selected video stream encodings
]]></artwork>
</figure>
<texttable anchor="table_8_1" title="5.8 SDP Offer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20519 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 62537 RTP/SAVPF 96</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:96 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=ssrc:12345 cname:axzo1278npDlAzM73</c>
<c><xref target="RFC5576"></xref> <xref target="draft-rescorla-avtcore-6222bis"></xref>
Camera-1,Encoding-1 SSRC with Session CNAME</c>
<c>a=ssrc:12345 imageattr:* [x=720,y=576]</c>
<c><xref target="RFC5576"></xref> Camera-1,Encoding-1 Resolution</c>
<c>a=ssrc:12345 framerate:30</c>
<c><xref target="RFC5576"></xref> Camera-1,Encoding-1 Framerate</c>
<c>a=ssrc:67890 cname:1NyKLomPs897HnrtU</c>
<c><xref target="RFC5576"></xref> <xref target="draft-rescorla-avtcore-6222bis"></xref>
Camera-1,Encoding-2 SSRC with Session CNAME</c>
<c>a=ssrc:67890 imageattr:* [x=176,y=144]</c>
<c><xref target="RFC5576"></xref> Camera-1,Encoding-2 Resolution</c>
<c>a=ssrc:67890 framerate:15</c>
<c><xref target="RFC5576"></xref> Camera-1, Encoding-2 Framerate</c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 62539 RTP/SAVPF 97</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:97 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=ssrc:54321 cname:o1278npDLOPzlAzM7</c>
<c><xref target="RFC5576"></xref> <xref target="draft-rescorla-avtcore-6222bis"></xref>
Camera-2,Encoding-1 SSRC with Session CNAME</c>
<c>a=ssrc:54321 imageattr:* [x=352,y=288]</c>
<c><xref target="RFC5576"></xref> Camera-2,Encoding-1 Resolution</c>
<c>a=ssrc:54321 framerate:30</c>
<c><xref target="RFC5576"></xref> Camera-2,Encoding-1 Framerate</c>
<c>a=ssrc:98760 cname:Yt54Jut99JgFvB23Q</c>
<c><xref target="RFC5576"></xref> <xref target="draft-rescorla-avtcore-6222bis"></xref>
Camera-2,Encoding-2 SSRC with Session CNAME</c>
<c>a=ssrc:98760 imageattr:* [x=176,y=144]</c>
<c><xref target="RFC5576"></xref> Camera-2,Encoding-2 Resolution</c>
<c>a=ssrc:98760 framerate:15</c>
<c><xref target="RFC5576"></xref> Camera-2,Encoding-2 Framerate</c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62539 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54723 typ host</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
<texttable anchor="table_8_2" title="5.8 SDP Answer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 63130 RTP/SAVPF 96</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:96 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=remote-ssrc:12345 recv:on</c>
<c><xref target="draft-lennox-mmusic-sdp-source-selection"></xref> Stream-1,Encoding-1 Accepted</c>
<c>a=remote-ssrc:67890 recv:off</c>
<c><xref target="RFC5576"></xref> Stream-1,Encoding-2 Not Accepted</c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Receive Only Video Stream 1</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63130 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56607 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 63133 RTP/SAVPF 97</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:97 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=remote-ssrc:54321 recv:off</c>
<c><xref target="draft-lennox-mmusic-sdp-source-selection"></xref> Stream-2, Encoding-1 Not Accepted</c>
<c>a=remote-ssrc:67890 recv:on</c>
<c><xref target="draft-lennox-mmusic-sdp-source-selection"></xref> Stream-2,Encoding-2 Accepted</c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Receive Only Video Stream 2</c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63133 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
</section>
<section anchor="sec.successful-session-svc"
title="Successful SVC Video Stream">
<t> In the example Offer/Answer exchange mechanism below, Alice Offers 3 media descriptions
of type video along with the layered decoding depencies between them. On the other hand,
Bob accepts only 2 of 3 Operation points offered by Alice.
</t>
<figure>
<artwork alt="Successful-Session SVC"
src="SessionSVC.png"><![CDATA[
title 2 way SVC Video
note right of Alice
Alice offers 3 sendonly video stream with 3 layers of SVC
end note
Alice->Bob: Offer(Video: H.264)
note left of Bob
Bob accepts Alice's Offer with 2 Operation Points of the 3
offered
end note
Bob->Alice: Answer(Video: H.264)
Alice->Bob: One-Way H.264 Video with encodings per instructed by Bob
]]></artwork>
</figure>
<texttable anchor="table_9_1" title="5.9 SDP Offer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20519 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=group:DDP L1 L2 L3</c>
<c><xref target="RFC5583"></xref> Streams L1,L2,L3 are grouped with layer decoding dependecy</c>
<c>m=video 62537 RTP/SAVPF 96 97</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:90</c>
<c><xref target="RFC4566"></xref></c>
<c>b=framerate:15</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:96 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:97 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=mid:L1</c>
<c><xref target="RFC5888"></xref></c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 62539 RTP/SAVPF 98 99</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:64</c>
<c><xref target="RFC4566"></xref></c>
<c>b=framerate:15</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:98 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:99 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=mid:L2</c>
<c><xref target="RFC5888"></xref></c>
<c>a=depend:98 lay L1:96,97; 99 lay L1:97</c>
<c><xref target="RFC5583"> </xref></c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62539 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54723 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 62890 RTP/SAVPF 100 101</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:128</c>
<c><xref target="RFC4566"></xref></c>
<c>b=framerate:30</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:100 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:101 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=mid:L3</c>
<c><xref target="RFC5888"></xref></c>
<c>a=depend:100 lay L1:96,97; 101 lay L1:97 L2:99</c>
<c><xref target="RFC5583"> </xref></c>
<c>a=sendonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62890 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54723 typ host</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
<texttable anchor="table_9_2" title="5.9 SDP Answer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=group:DDP L1 L2 L3</c>
<c><xref target="RFC5583"></xref> Streams L1,L2,L3 are grouped with layer decoding dependecy</c>
<c>m=video 62537 RTP/SAVPF 96 97</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.7711</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:90</c>
<c><xref target="RFC4566"></xref></c>
<c>b=framerate:15</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:96 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:97 H264/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=mid:L1</c>
<c><xref target="RFC5888"></xref></c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 62539 RTP/SAVPF 98 99</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:64</c>
<c><xref target="RFC4566"></xref></c>
<c>b=framerate:15</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:98 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:99 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=mid:L2</c>
<c><xref target="RFC5888"></xref></c>
<c>a=depend:98 lay L1:96,97; 99 lay L1:97</c>
<c><xref target="RFC5583"> </xref></c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62539 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54723 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 0 RTP/SAVPF 100 101</c>
<c><xref target="RFC4566"></xref> Port is set to 0 </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>b=AS:128</c>
<c><xref target="RFC4566"></xref></c>
<c>b=framerate:30</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:100 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=rtpmap:101 H264-SVC/90000</c>
<c><xref target="RFC3984"></xref></c>
<c>a=mid:L3</c>
<c><xref target="RFC5888"></xref></c>
<c>a=depend:100 lay L1:96,97; 101 lay L1:97 L2:99</c>
<c><xref target="RFC5583"> </xref></c>
<c>a=recvonly</c>
<c><xref target="RFC3264"></xref> - Send only video stream</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62890 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 54723 typ host</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
</section>
</section>
<section title="WebRTC <-> Legacy Interop Examples">
<t>
In this section, we attempt to provide session descriptions showcasing inter-operability
between a WebRTC end-point and a Legacy VOIP end-point. The ideas included in here
are not fully baked into the standards and might be controversial in nature. The hope here is
to demonstrate a plausible SDP composition to enchance seamless inter-operability between the
aforementioned communication systems.
</t>
<section anchor="successful-2way-webrtc-voip"
title="Secure Two-Way Audio,Video w/Feedback - WebRTC <-> Legacy Interop">
<t>
In the scenario desribed below, Alice sends <xref target="RFC3264"></xref> Offer with two
sets of media descriptions per media type.
<list>
<t> One set that correponds to <xref target="WEBRTC"></xref> Compliant RTP/SAVPF based audio and video descriptions.
</t>
<t> Another set with RTP/AVP based audio and video descriptions for the legacy Interop purposes. </t>
<t>
Also to note, Alice includes session level DTLS information and media level RTCP feedback information
as applicable to both the sets of media descriptions</t>
</list>
</t>
<t>
On the other hand, Bob being a Legacy VOIP end-point, recognizes only the media descriptions with RTP/AVP as the
application protocol.
The security and fedback requirements for the session are either handled by a intermediate gateway or with some
combination of Bob's capabilities and the intermediate gateway.
</t>
<figure>
<artwork alt="Successful-Session 2 Way SAVP VOIP"
src="Two-WaySAVP-VOIP.png"><![CDATA[
title Successful 2-Way WebRTC <-> VOIP Interop
note right of Alice
Alice is on a WebRTC end-point & Bob is behind a legacy VOIP system
end note
Alice->Bob: Offer(Audio:Opus Video:VP8)
note right of Alice
Alice includes 2 copies of media descriptions
1. WebRTC compliant media description (RTP/SAVPF)
2. Legacy compliant media description (RTP/AVP)
end note
Bob->Alice: Answer(Audio:Opus Video:VP8)
note right of Bob
Bob recognizes"legacy compliant" media description from Alice.
and accepts the same.
end note
Alice->Bob: Two-way Opus Audio, VP8 Video
note right of Alice
Session also suports RTP/RTCP Mux, RTCP feedback (nack,pli)
end note
]]></artwork>
</figure>
<texttable anchor="table_10_1" title="6.1 SDP Offer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=alice 20518 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:074c6550</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:a28a397a4c3f31747d1ee3474af08a068</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-rsize</c>
<c><xref target="RFC5506"></xref></c>
<c>m=audio 54609 RTP/SAVPF 109</c>
<c><xref target="RFC4566"></xref></c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54609 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54609 typ srflx raddr 192.168.1.4 rport 54609</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref></c>
<c>m=video 62537 RTP/SAVPF 120</c>
<c><xref target="RFC4566"></xref> </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62537 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 62537 typ srflx raddr 192.168.1.4 rport 62537</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 54721 typ srflx raddr 192.168.1.4 rport 54721</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref></c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
<c>---------------</c>
<c>These set of media descriptions are for Legacy Inter-op purposes</c>
<c>m=audio 54732 RTP/AVP 109</c>
<c><xref target="RFC4566"></xref>Alice includes RTP/AVP audio stream description</c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:7f:7d:f9:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref>Alice still includes RTP/RTCP Mux support</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 54732 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 694302207 24.23.204.141 54732 typ srflx raddr 192.168.1.4 rport 54732</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.4 64678 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 64678 typ srflx raddr 192.168.1.4 rport 64678</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:109 nack</c>
<c><xref target="RFC5104"></xref>She adds her intent for NACK RTCP feedback support</c>
<c>m=video 62445 RTP/AVP 120</c>
<c><xref target="RFC4566"></xref>Alice includes RTP/AVP video stream description </c>
<c>c= IN IP4 24.23.204.141</c>
<c><xref target="RFC4566"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:7d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=rtcp-mux</c>
<c><xref target="RFC5761"></xref>Alice intends to perform RTP/RTCP Mux</c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.4 62445 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 24.23.204.141 62537 typ srflx raddr 192.168.1.4 rport 62445</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 2113667326 192.168.1.4 54721 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 24.23.204.141 54721 typ srflx raddr 192.168.1.4 rport 54721</c>
<c><xref target="RFC5245"></xref></c>
<c>a=rtcp-fb:120 nack pli</c>
<c><xref target="RFC5104"></xref> Alice indicates support for Picture loss Indication and NACK RTCP feedback</c>
<c>a=rtcp-fb:120 ccm fir</c>
<c><xref target="RFC5104"></xref></c>
</texttable>
<texttable anchor="table_10_2" title="6.1 SDP Answer">
<ttcol align='left'>SDP Contents </ttcol>
<ttcol align='left'>RFC#/Notes</ttcol>
<c>v=0</c>
<c><xref target="RFC4566"></xref></c>
<c>o=bob 16833 0 IN IP4 0.0.0.0</c>
<c><xref target="RFC4566"></xref></c>
<c>s=</c>
<c><xref target="RFC4566"></xref></c>
<c>t=0 0</c>
<c><xref target="RFC4566"></xref></c>
<c>a=ice-ufrag:c300d85b</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ice-pwd:de4e99bd291c325921d5d47efbabd9a2</c>
<c><xref target="RFC5245"></xref></c>
<c>a=fingerprint:sha-1 99:41:49:83:4a:97:0e:1f:ef:6d:f7:c9:c7:70:9d:1f:66:79:a8:07</c>
<c><xref target="RFC5245"></xref></c>
<c>m=audio 49203 RTP/AVP 109</c>
<c><xref target="RFC4566"></xref> Bob accepts RTP/AVP based audio stream</c>
<c>c= IN IP4 98.248.92.77</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:109 opus/48000</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=ptime:20</c>
<c><xref target="draft-spittka-payload-rtp-opus"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 49203 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=ccandidate:1 1 UDP 1694302207 98.248.92.77 49203 typ srflx raddr 192.168.1.7 rport 49203</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 60065 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 60065 typ srflx raddr 192.168.1.7 rport 60065</c>
<c><xref target="RFC5245"></xref></c>
<c>m=video 63130 RTP/SAVP 120</c>
<c><xref target="RFC4566"></xref> Bob accepts RTP/AVP based video stram </c>
<c>c= IN IP4 98.248.92.771</c>
<c><xref target="RFC4566"></xref></c>
<c>a=rtpmap:120 VP8/90000</c>
<c><xref target="draft-ietf-payload-vp8"></xref></c>
<c>a=sendrecv</c>
<c><xref target="RFC3264"></xref></c>
<c>a=candidate:0 1 UDP 2113667327 192.168.1.7 63130 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 1 UDP 1694302207 98.248.92.77 63130 typ srflx raddr 192.168.1.7 rport 63130</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:0 2 UDP 2113667326 192.168.1.7 56607 typ host</c>
<c><xref target="RFC5245"></xref></c>
<c>a=candidate:1 2 UDP 1694302206 98.248.92.77 56607 typ srflx raddr 192.168.1.7 rport 56607</c>
<c><xref target="RFC5245"></xref></c>
</texttable>
</section>
</section>
<section title="IANA Considerations">
<t>This document requires no actions from IANA.</t>
</section>
<section title="Change Log">
<t>[RFC EDITOR NOTE: Please remove this section when publishing]</t>
<t>Changes from draft-nandakumar-rtcweb-sdp-00
<list style="symbols">
<t>Fixed editorial comments on the mailing list.</t>
<t>Updated Data-channel SDP information based on draft-ietf-mmusic-sctp-sdp.</t>
<t>Updated BUNDLE examples based on draft-ietf-mmusic-sdp-bundle-negotiation.</t>
<t>Added examples for few more BUNDLE variants</t>
<t>Added new examples for Simulcast and SVC</t>
</list>
</t>
</section>
</middle>
<back>
<references title="Normative References">
<reference anchor="RFC3264">
<front>
<title>An Offer/Answer Model with Session Description Protocol
(SDP)</title>
<author fullname="J. Rosenberg" initials="J." surname="Rosenberg">
<organization></organization>
</author>
<author fullname="H. Schulzrinne" initials="H."
surname="Schulzrinne">
<organization></organization>
</author>
<date month="June" year="2002" />
</front>
<seriesInfo name="RFC" value="3264" />
<format octets="60854"
target="http://www.rfc-editor.org/rfc/rfc3264.txt" type="TXT" />
</reference>
<reference anchor="RFC4566">
<front>
<title>SDP: Session Description Protocol</title>
<author fullname="M. Handley" initials="M." surname="Handley">
<organization></organization>
</author>
<author fullname="V. Jacobson" initials="V."
surname="Jacobson">
<organization></organization>
</author>
<author fullname="C. Perkins" initials="C."
surname="Perkins">
<organization></organization>
</author>
<date month="July" year="2006" />
</front>
<seriesInfo name="RFC" value="4566" />
<format octets="60854"
target="http://http://tools.ietf.org/html/rfc4566.txt" type="TXT" />
</reference>
<reference anchor="RFC2119">
<front>
<title abbrev="RFC Key Words">Key words for use in RFCs to Indicate
Requirement Levels</title>
<author fullname="Scott Bradner" initials="S." surname="Bradner">
<organization>Harvard University</organization>
<address>
<postal>
<street>1350 Mass. Ave.</street>
<street>Cambridge</street>
<street>MA 02138</street>
</postal>
<phone>- +1 617 495 3864</phone>
<email>sob@harvard.edu</email>
</address>
</author>
<date month="March" year="1997" />
<area>General</area>
<keyword>keyword</keyword>
</front>
<seriesInfo name="BCP" value="14" />
<seriesInfo name="RFC" value="2119" />
<format octets="4723"
target="http://www.rfc-editor.org/rfc/rfc2119.txt" type="TXT" />
<format octets="17491"
target="http://xml.resource.org/public/rfc/html/rfc2119.html"
type="HTML" />
<format octets="5777"
target="http://xml.resource.org/public/rfc/xml/rfc2119.xml"
type="XML" />
</reference>
</references>
<references title="Informative References">
<reference anchor="RFC5245">
<front>
<title>Interactive Connectivity Establishment (ICE):
A Protocol for Network Address Translator (NAT) Traversal for
Offer/Answer Protocols</title>
<author fullname="J. Rosenberj" initials="J." surname="Rosenberg">
<organization></organization>
</author>
<date month="July" year="2006" />
</front>
<seriesInfo name="RFC" value="5245" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc5245.txt" type="TXT" />
</reference>
<reference anchor="WEBRTC">
<front>
<title>
WebRTC 1.0: Real-time Communication Between Browsers
</title>
<author fullname="" initials="" surname="">
<organization>
W3C
</organization>
</author>
<date year="" month=""/>
</front>
<seriesInfo name="<http://dev.w3.org/2011/webrtc/editor/webrtc.html>" value=""/>
</reference>
<reference anchor="JSEP">
<front>
<title>
Javascript Session Establishment Protocol
</title>
<author fullname="J. Uberti" initials="J." surname="Uberti">
<organization>
Google
</organization>
</author>
<author fullname="JC. Jennings" initials="C." surname="Jennigs">
<organization>
Cisco Systems
</organization>
</author>
<date year="2012" month="December"/>
</front>
<seriesInfo name="Internet-Draft"
value="draft-ietf-rtcweb-jsep-01" />
<format target="http://tools.ietf.org/html/draft-ietf-rtcweb-jsep-01.txt"
type="TXT" />
</reference>
<reference anchor="RFC5506">
<front>
<title>Support for Reduced-Size Real-Time Transport Control Protocol (RTCP):
Opportunities and Consequences</title>
<author fullname="I. Johansson" initials="I." surname="Johansson">
<organization></organization>
</author>
<date month="April" year="2009" />
</front>
<seriesInfo name="RFC" value="5506" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc5506.txt" type="TXT" />
</reference>
<reference anchor="RFC3551">
<front>
<title>RTP Profile for Audio and Video Conferences
with Minimal Control</title>
<author fullname=" H. Schulzrinne" initials="H." surname="Schulzrinne">
<organization></organization>
</author>
<author fullname=" S. Casner" initials="S." surname="Casner">
<organization></organization>
</author>
<date month="July" year="2003" />
</front>
<seriesInfo name="RFC" value="3551" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc3551.txt" type="TXT" />
</reference>
<reference anchor="RFC3952">
<front>
<title>Real-time Transport Protocol (RTP) Payload Format
for internet Low Bit Rate Codec (iLBC) Speech</title>
<author fullname="A. Duric" initials="A." surname="Duric">
<organization></organization>
</author>
<author fullname="S. Andersen" initials="S." surname="Andersen">
<organization></organization>
</author>
<date month="December" year="2004" />
</front>
<seriesInfo name="RFC" value="3952" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc3952.txt" type="TXT" />
</reference>
<reference anchor="RFC4796">
<front>
<title>The Session Description Protocol (SDP) Content Attribute</title>
<author fullname="J. Hautakorpi" initials="J." surname="Hautakorpi">
<organization></organization>
</author>
<author fullname="G. Camarillo" initials="G." surname="Camarillo">
<organization></organization>
</author>
<date month="February" year="2007" />
</front>
<seriesInfo name="RFC" value="4796" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc4796.txt" type="TXT" />
</reference>
<reference anchor="RFC5761">
<front>
<title>Multiplexing RTP Data and Control Packets on a Single Port</title>
<author fullname="C. Perkins" initials="C." surname="Perkins">
<organization></organization>
</author>
<author fullname="M. Westerlund" initials="M." surname="Westerlund">
<organization></organization>
</author>
<date month="April" year="2010" />
</front>
<seriesInfo name="RFC" value="5761" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc5761.txt" type="TXT" />
</reference>
<reference anchor="RFC3556">
<front>
<title>Session Description Protocol (SDP) Bandwidth Modifiers
for RTP Control Protocol (RTCP) Bandwidth</title>
<author fullname="S. Casner" initials="S." surname="Casner">
<organization></organization>
</author>
<date month="July" year="2003" />
</front>
<seriesInfo name="RFC" value="3556" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc3556.txt" type="TXT" />
</reference>
<reference anchor="RFC5104">
<front>
<title>Codec Control Messages in the
RTP Audio-Visual Profile with Feedback (AVPF)</title>
<author fullname="S. Wenger" initials="S." surname="Wenger">
<organization></organization>
</author>
<author fullname="U. Chandra" initials="U." surname="Chandra">
<organization></organization>
</author>
<author fullname="M. Westerlund" initials="M." surname="Westerlund">
<organization></organization>
</author>
<author fullname="B. Burman" initials="B." surname="Burman">
<organization></organization>
</author>
<date month="February" year="2008" />
</front>
<seriesInfo name="RFC" value="5104" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc5104.txt" type="TXT" />
</reference>
<reference anchor="RFC5888">
<front>
<title>RTP Payload Format for H.264 Video</title>
<author fullname="G. Camarillo" initials="G." surname="Camarillo">
<organization></organization>
</author>
<author fullname="H. Schulzrinne" initials="H." surname="Schulzrinne">
<organization></organization>
</author>
<date month="June" year="2010" />
</front>
<seriesInfo name="RFC" value="3984" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc3984.txt" type="TXT" />
</reference>
<reference anchor="draft-spittka-payload-rtp-opus">
<front>
<title>RTP Payload Format for Opus Speech and Audio Codec</title>
<author fullname=" J. Spittka" initials="J." surname=" Spittka">
<organization></organization>
</author>
<author fullname="K. Vos" initials="K." surname="Vos">
<organization></organization>
</author>
<author fullname="JM. Valin" initials="JM." surname="Valin">
<organization></organization>
</author>
<date month="July" year="2012" />
</front>
<seriesInfo name="Internet-Draft"
value="draft-spittka-payload-rtp-opus-01" />
<format target="http://tools.ietf.org/id/draft-spittka-payload-rtp-opus-01.txt"
type="TXT" />
</reference>
<reference anchor="draft-ietf-payload-vp8">
<front>
<title>RTP Payload Format for VP8 Video</title>
<author fullname=" P. Westin" initials="P." surname="Westin">
<organization></organization>
</author>
<author fullname="H. Lundin" initials="H." surname="Lundin">
<organization></organization>
</author>
<author fullname="M. Glover" initials="M." surname="Glover">
<organization></organization>
</author>
<author fullname="J. Uberti" initials="J." surname="Uberti">
<organization></organization>
</author>
<author fullname="F. Galligan" initials="F." surname="Galligan">
<organization></organization>
</author>
<date month="August" year="2012" />
</front>
<seriesInfo name="Internet-Draft"
value="draft-ietf-payload-vp8-05" />
<format target="http://tools.ietf.org/html/draft-ietf-payload-vp8-05"
type="TXT" />
</reference>
<reference anchor="RFC3984">
<front>
<title>RTP Payload Format for H.264 Video</title>
<author fullname="S. Wenger" initials="S." surname="Wenger">
<organization></organization>
</author>
<author fullname="M.M. Hannuksela" initials="M.M" surname="Hannuksela">
<organization></organization>
</author>
<author fullname="T. Stockhammer" initials="T." surname="Stockhammer">
<organization></organization>
</author>
<author fullname="M. Westerlund" initials="M." surname="Westerlund">
<organization></organization>
</author>
<author fullname="D. Singer" initials="D." surname="Singer">
<organization></organization>
</author>
<date month="February" year="2005" />
</front>
<seriesInfo name="RFC" value="3984" />
<format octets="60854"
target="http://tools.ietf.org/html/rfc3984.txt" type="TXT" />
</reference>
<reference anchor='RFC5583'>
<front>
<title>Signaling Media Decoding Dependency in the Session Description Protocol (SDP)</title>
<author initials='T.' surname='Schierl' fullname='T. Schierl'>
<organization /></author>
<author initials='S.' surname='Wenger' fullname='S. Wenger'>
<organization /></author>
<date year='2009' month='July' />
<abstract>
<t>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 streams as a result of the use of a layered or multiple descriptive media coding process.</t><t> 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). [STANDARDS-TRACK]</t></abstract></front>
<seriesInfo name='RFC' value='5583' />
<format type='TXT' octets='40214' target='http://www.rfc-editor.org/rfc/rfc5583.txt' />
</reference>
<reference anchor='RFC5576'>
<front>
<title>Source-Specific Media Attributes in the Session Description Protocol (SDP)</title>
<author initials='J.' surname='Lennox' fullname='J. Lennox'>
<organization /></author>
<author initials='J.' surname='Ott' fullname='J. Ott'>
<organization /></author>
<author initials='T.' surname='Schierl' fullname='T. Schierl'>
<organization /></author>
<date year='2009' month='June' />
<abstract>
<t>The Session Description Protocol (SDP) 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, which are identified by their synchronization source (SSRC) identifiers, in SDP, to associate attributes with these sources, and to express relationships among sources. It also defines several source-level attributes that can be used to describe properties of media sources. [STANDARDS-TRACK]</t></abstract></front>
<seriesInfo name='RFC' value='5576' />
<format type='TXT' octets='40454' target='http://www.rfc-editor.org/rfc/rfc5576.txt' />
</reference>
<reference anchor="draft-ietf-rtcweb-data-channel">
<front>
<title>RTCWeb Datagram Connection</title>
<author fullname=" R. Jesup" initials="R." surname="Jesup">
<organization></organization>
</author>
<author fullname="S. Loreto" initials="S." surname="Loreto">
<organization></organization>
</author>
<author fullname="M. Tuexen" initials="M." surname="Tuexen">
<organization></organization>
</author>
<date month="September" year="2012" />
</front>
<seriesInfo name="Internet-Draft"
value="draft-ietf-rtcweb-data-channel-01" />
<format target="http://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-01"
type="TXT" />
</reference>
<reference anchor="draft-ietf-mmusic-sctp-sdp">
<front>
<title>Stream Control Transmission Protocol (SCTP)-Based Media Transport in the
Session Description Protocol (SDP)</title>
<author fullname="Salvatore Loreto" initials="S." surname="Loreto">
<organization></organization>
</author>
<author fullname="Gonzalo Camarillo" initials="G." surname="Camarillo">
<organization></organization>
</author>
<date month="September" year="2012" />
</front>
<seriesInfo name="Internet-Draft"
value="draft-ietf-mmusic-sctp-sdp-03" />
<format target="http://tools.ietf.org/html/draft-ietf-mmusic-sctp-sdp-03"
type="TXT" />
</reference>
<reference anchor="draft-ietf-mmusic-sdp-bundle-negotiation">
<front>
<title> Multiplexing Negotiation Using Session Description Protocol (SDP) Port
Numbers</title>
<author fullname="Christer Holmberg" initials="C." surname="Holmberg">
<organization></organization>
</author>
<author fullname="Harald Tveit Alvestrand" initials="H." surname="Alvestrand">
<organization></organization>
</author>
<author fullname="Cullen Jennings" initials="C." surname="Jennings">
<organization></organization>
</author>
<date month="February" year="2013" />
</front>
<seriesInfo name="Internet-Draft"
value="draft-ietf-mmusic-sdp-bundle-negotiation-03" />
<format target="http://tools.ietf.org/html/draft-ietf-mmusic-sdp-bundle-negotiation-03"
type="TXT" />
</reference>
<reference anchor="draft-lennox-mmusic-sdp-source-selection">
<front>
<title> Multiplexing Negotiation Using Session Description Protocol (SDP) Port
Numbers</title>
<author fullname="Jonathan Lennox" initials="J." surname="Lennox">
<organization></organization>
</author>
<author fullname="Henning Schulzrinne" initials="H." surname="Schulzrinne">
<organization></organization>
</author>
<date month="October" year="2012" />
</front>
<seriesInfo name="Internet-Draft"
value="draft-lennox-mmusic-sdp-source-selection-05" />
<format target="http://tools.ietf.org/html/draft-lennox-mmusic-sdp-source-selection-05"
type="TXT" />
</reference>
<reference anchor="draft-rescorla-avtcore-6222bis">
<front>
<title> Guidelines for Choosing RTP Control Protocol (RTCP)
Canonical Names (CNAMEs)</title>
<author fullname="Eric Rescorla" initials="E." surname="Rescorla">
<organization></organization>
</author>
<author fullname="Ali Begen" initials="A." surname="Begen">
<organization></organization>
</author>
<date month="October" year="2012" />
</front>
<seriesInfo name="Internet-Draft"
value="draft-rescorla-avtcore-6222bis-00" />
<format target="http://tools.ietf.org/html/draft-rescorla-avtcore-6222bis-00"
type="TXT" />
</reference>
</references>
</back>
</rfc>
| PAFTECH AB 2003-2026 | 2026-04-24 02:37:29 |