One document matched: draft-ietf-mmusic-sdp-mux-attributes-02.xml
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<?rfc toc="yes" ?>
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<rfc category="std" docName="draft-ietf-mmusic-sdp-mux-attributes-02"
ipr="trust200902">
<front>
<title abbrev="SDP Attribute Multiplexing">A Framework for SDP Attributes
when Multiplexing</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>
<date day="03" month="July" year="2014" />
<area>MMUSIC</area>
<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. In the RTCWeb WG, there is a need to use a
single 5-tuple for sending and receiving media associated with multiple
media descriptions ("m=" lines). Such a requirement has raised concerns
over the semantic implications of the SDP attributes associated with the
RTP Media Streams multiplexed over a single transport layer flow.
</t>
<t>
The scope of this specification is to provide a framework for analyzing
the multiplexing characteristics of SDP attributes. The specification also
categorizes existing attributes based on the framework described herein.
</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>
Real-Time Communication Web (RTCWeb) framework requires Real-time Transport
Protocol (RTP) as the media transport protocol and Session
Description Protocol (SDP) <xref target="RFC4566"/> for describing and negotiating
multi-media communication sessions.
</t>
<t>
SDP defines several attributes for capturing characteristics that apply
to the individual media descriptions (described by "m=" lines") and the overall
multimedia session.
Typically different media types (audio, video etc) described using
different media descriptions represent separate RTP Sessions that are carried
over individual transport layer flows.
However in the IETF RTCWEB WG, a need to use a single 5-tuple for sending and
receiving media associated with multiple SDP media descriptions ("m="
lines) has been identified. This would e.g. allow the usage of a
single set of Interactive Connectivity Establishment (ICE) [RFC5245]
candidates for multiple media descriptions.
This in turn has made necessary to understand the interpretation
and usage of the SDP attributes defined for the multiplexed media descriptions.
</t>
<t>
Given the number of SDP attributes registered with the IANA
<xref target="IANA"></xref> and possibility of new attributes being defined in
the future, there is need for generic future-proof framework to analyze these
attributes for their applicability in the transport multiplexing use-cases.
</t>
<t>
The document starts with providing the motivation for requiring such a
framework. This is followed by introduction
to the SDP attribute analysis framework/procedures, following which
several sections applies the framework to the SDP attributes registered
with the IANA <xref target="IANA"></xref>
</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="Motivation">
<t>
The time and complications of setting up ICE <xref target="RFC5245"></xref>
and DTLS-SRTP <xref target="RFC5763"></xref> transports for use by RTP, and
conservation of ports, forms an requirement to try and reduce the number of
transport level flows needed.
This has resulted in the definition of ways, such as,
<xref target="I-D.ietf-mmusic-sdp-bundle-negotiation"></xref> and
<xref target="I-D.ietf-avt-multiplexing-rtp"></xref> to multiplex RTP over
a single transport flow in order to preserve network resources such as
port numbers. This imposes further restrictions on applicability of these SDP
attributes as they are defined today.
</t>
<t>
The specific problem is that there are attribute combinations which
make sense when specified on independent m-lines -- as with
classical SDP -- that do not make sense when those m-lines are
then multiplexed over the same transport. To give an obvious
example, ICE permits each m=line to have an independently
specified ice-ufrag attribute. However, if the media from
multiple m-lines is multiplexed over the same ICE component,
then the meaning of media-level ice-ufrag attributes becomes
muddled.
</t>
<t>
As of today there are close to 250 SDP attributes registered
with the IANA <xref target="IANA"></xref> and more will be added in
the future. There is no clearly defined procedure to establish the
validity/applicability of these attribute when used with transport multiplexing.
</t>
</section>
<section title="SDP Attribute Analysis Framework">
<t>
Attributes in an SDP session description can be defined at the session-level and
media-level. These attributes could be semantically grouped as noted below.
</t>
<t>
<list style="symbols">
<t> Attributes related to media content such as media type,
encoding schemes, payload types.</t>
<t> Attributes specifying media transport characteristics like RTP/RTCP
port numbers, network addresses, QOS.</t>
<t> Metadata description attributes capturing session timing and origin
information.</t>
<t> Attributes establishing relationships between media streams such as
grouping framework</t>
</list>
</t>
<t>
With the above semantic grouping as the reference, the proposed framework classifies
each attribute into one of the following categories:
</t>
<section title="Category: NORMAL">
<t>Attributes that can be independently specified when multiplexing and retain
their original semantics.</t>
<t> </t>
<t>
In the example given below, the direction and label attributes are independently
specified for audio and video m=lines. These attributes are not impacted
by multiplexing these media streams over a single transport layer flow.
</t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=alice 2890844526 2890844527 IN IP4 host.atlanta.example.com
s=
c=IN IP4 host.atlanta.example.com
t=0 0
m=audio 49172 RTP/AVP 99
a=sendonly
a=label:1
a=rtpmap:99 iLBC/8000
m=video 49172 RTP/AVP 31
a=recvonly
a=label:2
a=rtpmap:31 H261/90000
]]></artwork>
</figure>
<t> </t>
</section>
<section title="Category: NOT RECOMMENDED">
<t>
Attributes that are recommended against multiplexing since their usage under
multiplexing might lead to incorrect behavior.
</t>
<t> </t>
<t>
Example: Multiplexing media descriptions having attribute zrtp-hash defined
with the media descriptions lacking it, would either complicate the handling of
multiplexed streams or might fail multiplexing altogether.
</t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=bob 2890844527 2890844527 IN IP4 client.biloxi.example.com
s=
c=IN IP4 client.biloxi.example.com
t=0 0
m=audio 3456 RTP/AVP 97 // with zrtp
a=rtpmap:97 iLBC/8000
<allOneLine>
a=zrtp-hash:1.10 fe30efd02423cb054e50efd0248742ac7a52c8f91bc2
df881ae642c371ba46df
</allOneLine>
m=video 34567 RTP/AVP 31 //without zrtp
a=rtpmap:31 H261/90000
]]></artwork>
</figure>
<t> </t>
</section>
<section title="Category: IDENTICAL">
<t>Attributes that MUST be identical across all the media descriptions
being multiplexed.</t>
<t> </t>
<t>
Attributes such as rtcp-mux fall into this category.
Since RTCP reporting is done per RTP Session, RTCP Multiplexing
MUST to enabled for both the audio and video m=lines in the
example below if they are transported over a single 5-tuple.
</t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=bob 2890844527 2890844527 IN IP4 client.biloxi.example.com
s=
c=IN IP4 client.biloxi.example.com
t=0 0
m=audio 34567 RTP/AVP 97
a=rtcp-mux
m=video 34567 RTP/AVP 31
a=rtpmap:31 H261/90000
a=rtcp-mux
]]></artwork>
</figure>
<t> </t>
</section>
<section title="Category: SUM">
<t>Attributes can be set as they are normally used but
software using them in a multiplex case, MUST apply the sum of all the
attributes being multiplexed instead of trying to use each one. This is
typically used for bandwidth or other rate limiting attributes to the
underlining transport. </t>
<t> </t>
<t>
The software parsing the SDP sample below, should use the aggregate
Application Specific (AS) bandwidth value from the individual media descriptions
to determine the AS value for the multiplexed session.
Thus the calculated AS value would be 256+64 bytes for the given example.
</t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=mhandley 2890844526 2890842807 IN IP4 126.16.64.4
c=IN IP4 client.biloxi.example.com
t=0 0
m=audio 49170 RTP/AVP 0
b=AS:64
m=video 51372 RTP/AVP 31
b=AS:256
]]></artwork>
</figure>
<t> </t>
</section>
<section title="Category: TRANSPORT">
<t> Attributes that can be set normally for
multiple items in a multiplexed group but the software MUST pick just
one of the attribute of the given type for use. The one chosen is the
attribute associated with the "m=" line that represents the information
being used for the transport of the RTP.</t>
<t> </t>
<t>
In the example below, "a=crypto" attribute is defined for both the audio and
the video m=lines. The video media line's a=crypto attribute is chosen since
its mid value (bar) appears first in the a=group:BUNDLE line. This is due to
BUNDLE grouping semantic <xref target="I-D.ietf-mmusic-sdp-bundle-negotiation"></xref>
which mandates the values from m=line corresponding to the mid appearing first
on the a=group:BUNDLE line to be considered for setting up the RTP Transport.
</t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=alice 2890844526 2890844527 IN IP4 host.atlanta.example.com
s=
c=IN IP4 host.atlanta.example.com
t=0 0
a=group:BUNDLE bar foo
m=audio 49172 RTP/AVP 99
a=mid:foo
a=crypto:1 AES_CM_128_HMAC_SHA1_80
inline:d0RmdmcmVCspeEc3QGZiNWpVLFJhQX1cfHAwJSoj|2^20|1:32
a=rtpmap:99 iLBC/8000
m=video 51374 RTP/AVP 31
a=mid:bar
a=crypto:1 AES_CM_128_HMAC_SHA1_80
inline:EcGZiNWpFJhQXdspcl1ekcmVCNWpVLcfHAwJSoj|2^20|1:32
a=rtpmap:96 H261/90000
]]></artwork>
</figure>
<t> </t>
</section>
<section title="Category: INHERIT">
<t> Attributes that encapsulate other SDP attributes and
their multiplexing characteristics are inherited from the attributes they encapsulate.
Such attributes as of today, are defined in [RFC3407], [RFC5939] and [RFC6871] as part
of a generic framework for indicating and negotiating transport, media and media format
related capabilities in the SDP. </t>
<t> </t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=alice 2890844526 2890844527 IN IP4 host.atlanta.example.com
s=
c=IN IP4 host.atlanta.example.com
t=0 0
m=video 3456 RTP/AVP 100
a=rtpmap:100 VP8/90000
a=fmtp:100 max-fr=30;max-fs=8040
a=sqn: 0
a=cdsc: 1 video RTP/AVP 100
a=cpar: a=rtcp-mux
m=video 3456 RTP/AVP 101
a=rtpmap:101 VP8/90000
a=fmtp:100 max-fr=15;max-fs=1200
a=cdsc: 2 video RTP/AVP 101
a=cpar: a=rtcp-mux
]]></artwork>
</figure>
<t>
In the above example , the category IDENTICAL is inherited for the cpar
encapsulated rtcp-mux attribute.
</t>
<t> </t>
</section>
<section title="Category: IDENTICAL-PER-PT">
<t> Attributes that define the RTP payload configuration
on per Payload Type basis and MUST have identical values across all the media descriptions
for a given RTP Payload Type when repeated.</t>
<t> </t>
<t>
In the SDP example below, Payload Types 96 and 97 are repeated across
all the video m= lines and all the payload specific parameters (ex: rtpmap,
fmtp) are identical.
</t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=alice 2890844526 2890844527 IN IP4 host.atlanta.example.com
s=
c=IN IP4 host.atlanta.example.com
t=0 0
a=group:BUNDLE cam1, cam2
m = video 96 97
a=mid:cam1
a=rtpmap:96 H264/90000
a=fmtp:96 profile-level-id=42400d; max-fs=3600; max-fps=3000;
max-mbps=108000; max-br=1000
a=rtpmap:97 H264/90000
a=fmtp:97 profile-level-id=42400a; max-fs=240; max-fps=3000;
max-mbps=7200; max-br=200
m = video 96 97
a=mid:cam2
a=rtpmap:96 H264/90000
a=fmtp:96 profile-level-id=42400d; max-fs=3600; max-fps=3000;
max-mbps=108000; max-br=1000
a=rtpmap:97 H264/90000
a=fmtp:97 profile-level-id=42400a; max-fs=240; max-fps=3000;
max-mbps=7200; max-br=200
]]>
</artwork>
</figure>
<t> </t>
</section>
<section title="Category: SPECIAL">
<t> Attributes where the text in the source draft must be
consulted for further handling when multiplexed. </t>
<t> As an example, for the attribute extmap, the specification
defining the extension MUST be referred to understand the multiplexing implications.
</t>
</section>
</section>
<section title="Analysis of Existing Attributes" anchor="SecCurrAnalysis" >
<t>
This section analyzes attributes listed in <xref target="IANA">IANA</xref>
grouped under the IETF document that defines them. The "Level" column indicates
whether the attribute is currently specified as:
</t>
<t>
<list style="symbols">
<t>S -- Session level</t>
<t>M -- Media level</t>
<t>B -- Both</t>
<t>SR -- Source-level (for a single SSRC)</t>
</list>
</t>
<section title="RFC4566 - SDP: Session Description Protocol">
<t>
<xref target="RFC4566">RFC4566</xref> defines the Session Description Protocol (SDP)
that is intended for describing multimedia sessions for the purposes of session
announcement, session invitation, and other forms of multimedia session
initiation
</t>
<texttable title="RFC4566 Attribute Analysis">
<ttcol align='left'>Attr Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>sendrecv </c><c>Not impacted </c><c>B </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>sendonly </c><c>Not impacted </c><c>B </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>recvonly </c><c>Not impacted </c><c>B </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>inactive </c><c>Not impacted </c><c>B </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>cat </c><c>Not impacted </c><c>S </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ptime </c><c> The attribute value must be same
for a given codec configuration </c>
<c>M </c><c>IDENTICAL-PER-PT</c>
<c> </c><c> </c><c> </c><c> </c>
<c>maxptime </c><c>The attribute value must be same
for a given codec configuration </c>
<c>M </c><c>IDENTICAL-PER-PT</c>
<c> </c><c> </c><c> </c><c> </c>
<c>orient </c><c>Not Impacted
</c><c>M </c><c>NORMAL</c>
<c> </c><c> </c><c> </c><c> </c>
<c>framerate </c><c>The attribute value must be same
for a given codec configuration </c><c>M </c>
<c>IDENTICAL-PER-PT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>quality </c><c>Not Impacted
</c><c>M </c><c>NORMAL</c>
<c> </c><c> </c><c> </c><c> </c>
<c>rtpmap </c><c>The attribute value must be same
for a given codec configuration </c><c>M </c>
<c>IDENTICAL-PER-PT</c>
<c> </c><c> </c><c> </c><c> </c>
<c>fmtp </c><c>The attribute value must be same
for a given codec configuration </c><c>M </c>
<c>IDENTICAL-PER-PT</c>
<c> </c><c> </c><c> </c><c> </c>
<c>keywds </c><c>Not impacted </c><c>S </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>type </c><c>Not Impacted
</c><c>S </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>tool </c><c>Not Impacted
</c><c>S </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>charset </c><c>Not Impacted
</c><c>S </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>sdplang </c><c>Not Impacted
</c><c>B </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>lang </c><c>Not Impacted
</c><c>B </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4585 - RTP/AVPF">
<t>
<xref target="RFC4585">RFC4585</xref> defines an extension to the
Audio-visual Profile (AVP) that enables receivers to provide, statistically,
more immediate feedback to the senders and thus allows for short-term
adaptation and efficient feedback-based repair mechanisms to be implemented.
</t>
<texttable title="RFC4585 Attribute Analysis">
<ttcol align='left'>Attr Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rtcp-fb </c><c>The combination of a particular Payload Type along
with the m=line identify the scope and applicability of a given RTCP feedback to a
particular RTP Stream.</c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note">
Since RTCP feedback attributes are Payload Type (PT) scoped, the usage of
identical Payload Type values across multiplexed m=lines is described in
<xref target="I-D.ietf-mmusic-sdp-bundle-negotiation"></xref>.
</t>
</section>
<section title="RFC5761 - Multiplexing RTP and RTCP">
<t>
<xref target="RFC5761">RFC5761</xref> discusses issues that arise
when multiplexing RTP data packets and RTP Control Protocol (RTCP)
packets on a single UDP port. It
describes when such multiplexing is and is not appropriate, and
it explains how the Session Description Protocol (SDP) can be used
to signal multiplexed sessions.
</t>
<texttable title="RFC5761 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rtcp-mux </c><c>RTP and RTCP Multiplexing affect the entire RTP Session </c>
<c>M </c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4574 - SDP Label Attribute ">
<t>
<xref target="RFC4574">RFC4574</xref> defines a new
Session Description Protocol (SDP)
media-level attribute: "label". The "label" attribute carries a
pointer to a media stream in the context of an arbitrary network
application that uses SDP. The sender of the SDP document can attach
the "label" attribute to a particular media stream or streams. The
application can then use the provided pointer to refer to each
particular media stream in its context.
</t>
<texttable title="RFC4574 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>label </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5432 - QoS Mechanism Selection in SDP">
<t>
<xref target="RFC5432">RFC5432</xref> defines procedures to negotiate
QOS mechanisms using the Session Description Protocol (SDP)
offer/answer model.
</t>
<texttable title="RFC5432 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>qos-mech-send </c>
<c> A single DSCP code point per flow being multiplexed
doesn't impact multiplexing since QOS mechanisms are
signaled/scoped per flow. </c>
<c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>qos-mech-recv </c>
<c>A single DSCP code point per flow being multiplexed
doesn't impact multiplexing since QOS mechanisms are
signaled/scoped per flow. </c>
<c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note">
Multiplexing consideration when multiple DSCP code points are defined per flow
can be found in <xref target="dscp-mux"/>
</t>
</section>
<section title="RFC4568 - SDP Security Descriptions">
<t>
<xref target="RFC4568">RFC4568</xref> defines a Session Description Protocol (SDP)
cryptographic attribute for unicast media streams. The attribute
describes a cryptographic key and other parameters that serve to
configure security for a unicast media stream in either a single
message or a roundtrip exchange.
</t>
<texttable title="RFC4568 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>crypto </c><c>Refer to section 6.2.5 of <xref target="I-D.ietf-mmusic-sdp-bundle-negotiation"></xref></c>
<c>M </c><c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note">
If the multiplexing scheme cannot ensure unique SSRCs across all
the media lines, multiplexing MUST NOT be performed.
</t>
</section>
<section title="RFC5762 - RTP over DCCP">
<t>
The Real-time Transport Protocol (RTP) is a widely used transport for
real-time multimedia on IP networks. The Datagram Congestion Control
Protocol (DCCP) is a transport protocol that provides desirable
services for real-time applications. <xref target="RFC5762">RFC5762</xref>
specifies a mapping of RTP onto DCCP, along with associated signaling,
such that real-time applications can make use of the services provided by DCCP
</t>
<texttable title="RFC5762 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Current</ttcol>
<ttcol align='left'>Category</ttcol>
<c>dccp-service-code </c><c> If RFC6773 is not being used in addition to RFC5762,
the port in the m= line is a DCCP port. DCCP being a connection oriented protocol,
does not allow multiple connections on the same 5-tuple. </c>
<c>M </c><c>NOT RECOMMENDED </c><c> </c>
<c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note">
If RFC6773 is being used in addition to RFC5762 and provided
that DCCP-in-UDP layer has additional demultiplexing, then it may be
possible to use different DCCP service codes for each DCCP flow, given
each uses a different DCCP port. Although doing so might conflict with the
media type of the m= line. None of this is standardized yet and it
wouldn't work as explained. Hence multiplexing MUST NOT be performed even in this
alternate scenario.
</t>
</section>
<section title="RFC6773 - DCCP-UDP Encapsulation">
<t>
<xref target="RFC6773">RFC6773</xref> document specifies an alternative
encapsulation of the Datagram Congestion Control Protocol (DCCP),
referred to as DCCP-UDP. This encapsulation allows DCCP to be carried
through the current generation of Network Address Translation (NAT) middle boxes
without modification of those middle boxes
</t>
<texttable title="RFC6773 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>dccp-port </c><c> Multiplexing MUST NOT be performed due to potential
conflict between the port used for DCCP en/decapsulation and the RTP. </c>
<c>M </c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note">
Since RFC6773 is about tunnelling DCCP in UDP, with the UDP port being the port
of the DCCP en-/de-capsulation service. This encapsulation allows arbitrary DCCP packets to be encapsulated and the DCCP port choosen MAY conflict with the
port chosen for the RTP traffic.
</t>
<t>
For multiplexing several DCCP-in-UDP encapsulations on the same UDP port, with no RTP traffic on the same port implies collapsing several DCCP port spaces together.
This MAY or MAY NOT work depending on the nature of DCCP encapsulations and ports choses thus rendering it to be very application dependant.
</t>
</section>
<section title="RFC5506 - Reduced-Size RTCP in RTP Profile">
<t>
<xref target="RFC5506">RFC5506</xref> discusses benefits and issues that
arise when allowing Real-time Transport Protocol (RTCP) packets to be
transmitted with reduced size.
</t>
<texttable title="RFC5506 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rtcp-rsize </c><c>Reduced size RTCP affects the entire RTP Session </c>
<c>M </c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6787 - Media Resource Control Protocol Version 2">
<t>
The Media Resource Control Protocol Version 2 (MRCPv2) allows client
hosts to control media service resources such as speech synthesizers,
recognizers, verifiers, and identifiers residing in servers on the
network. MRCPv2 is not a "stand-alone" protocol -- it relies on
other protocols, such as the Session Initiation Protocol (SIP), to
coordinate MRCPv2 clients and servers and manage sessions between
them, and the Session Description Protocol (SDP) to describe,
discover, and exchange capabilities. It also depends on SIP and SDP
to establish the media sessions and associated parameters between the
media source or sink and the media server. Once this is done, the
MRCPv2 exchange operates over the control session established above,
allowing the client to control the media processing resources on the
speech resource server. <xref target="RFC6787">RFC6787</xref> defines
attributes for this purpose.
</t>
<texttable title="RFC6787 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>resource </c><c>Not Impacted </c><c>M </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>channel </c><c>Not Impacted </c><c>M </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5245 - Interactive Connectivity Establishment (ICE)">
<t>
<xref target="RFC5245">RFC5245</xref> describes a protocol for
Network Address Translator(NAT) traversal for UDP-based multimedia
sessions established with the offer/answer model. This protocol
is called Interactive Connectivity Establishment (ICE).
ICE makes use of the Session Traversal Utilities for NAT (STUN) protocol
and its extension,Traversal Using Relay NAT (TURN). ICE can be used
by any protocol utilizing the offer/answer model, such as the
Session Initiation Protocol (SIP).
</t>
<texttable title="RFC5245 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>ice-lite </c><c>Not Impacted </c>
<c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ice-options </c><c>Not Impacted </c>
<c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ice-pwd </c><c>ice-pwd MUST be the one that
corresponds to the m=line chosen for setting up the
underlying transport flow </c>
<c>B</c><c>TRANSPORT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ice-ufrag </c><c>ice-ufrag MUST be the one that
corresponds to the m=line chosen for setting up the
underlying transport flow </c>
<c>B</c><c>TRANSPORT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>candidate </c><c>ice candidate MUST be the one that
corresponds to the m=line chosen for setting up the
underlying transport flow </c><c>M</c><c>TRANSPORT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>remote-candidates </c><c>ice remote candidate MUST be the
one that corresponds to the m=line chosen for setting up the
underlying transport flow </c><c>M</c><c>TRANSPORT </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5285 - RTP Header Extensions">
<t>
<xref target="RFC5285">RFC5285</xref> provides a general mechanism to use the header
extension feature of RTP (the Real-Time Transport Protocol). It
provides the option to use a small number of small extensions in each
RTP packet, where the universe of possible extensions is large and
registration is de-centralized. The actual extensions in use in a
session are signaled in the setup information for that session.
</t>
<texttable title="RFC5285 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>extmap </c><c>Specific RTP extension document MUST be referred </c>
<c>B</c><c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC3605 - RTCP attribute in SDP ">
<t>
Originally, SDP assumed that RTP and RTCP were carried on consecutive
ports. However, this is not always true when NATs are involved.
<xref target="RFC3605"/> specifies an early mechanism to
indicate the RTCP port.
</t>
<texttable title="RFC3605 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rtcp </c><c>Identical attribute value MUST be used since the RTCP port affects
the entire RTP session. </c><c>M</c>
<c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5576 - Source-Specific SDP Attributes">
<t>
<xref target="RFC5576">RFC5576</xref> 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.</t>
<texttable title="RFC5576 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>ssrc </c><c>Refer to Notes below </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ssrc-group </c>
<c>Refer to section <xref target="SecssrcgroupAnalysis"></xref>
for specific analysis of the grouping semantics </c><c>M</c>
<c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>cname </c>
<c>Not Impacted [Open Issues: what are the rules for CNAME duplication
across sessions?] </c><c>SR</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>previous-ssrc </c>
<c>Refer to notes below </c><c>SR</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>fmtp </c><c>The attribute value must be same
for a given codec configuration </c><c>SR</c><c>IDENTICAL-PER-PT </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note">
If SSRCs are repeated across m=lines being multiplexed, they MUST all represent the
same underlying RTP Source. For more details on implications of SSRC values
with in the context of multiplexing please refer to
<xref target="I-D.ietf-mmusic-sdp-bundle-negotiation"></xref>
</t>
</section>
<section title="RFC6236 - Image Attributes in SDP">
<t>
<xref target="RFC6236">RFC6236</xref> proposes a new generic session
setup attribute to make it possible to negotiate different image attributes
such as image size. A possible use case is to make it possible for a
low-end hand-held terminal to display video without the need to
rescale the image,something that may consume large amounts of memory
and processing power. The document also helps to maintain an optimal
bitrate for video as only the image size that is desired by the
receiver is transmitted.
</t>
<texttable title="RFC6236 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>imageattr </c><c>The attribute value must be same
for a given codec configuration </c><c>M </c>
<c>IDENTICAL-PER-PT </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6285 - Rapid Acquisition of Multicast RTP Sessions">
<t>
<xref target="RFC6285">RFC6285</xref> describes a method using the
existing RTP and RTP Control Protocol (RTCP) machinery that reduces
the acquisition delay. In this method, an auxiliary unicast RTP session
carrying the Reference Information to the receiver precedes or accompanies the
multicast stream. This unicast RTP flow can be transmitted at a
faster than natural bitrate to further accelerate the acquisition.
The motivating use case for this capability is multicast applications
that carry real-time compressed audio and video.
</t>
<texttable title="RFC6285 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rams-updates </c><c>Not recommended </c><c>M </c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6230 - Media Control Channel Framework">
<t>
<xref target="RFC6230">RFC6230</xref> describes a framework and
protocol for application deployment where the application programming
logic and media processing are distributed. This implies that application
programming logic can seamlessly gain access to appropriate resources
that are not co-located on the same physical network entity. The
framework uses the Session Initiation Protocol (SIP) to establish an
application-level control mechanism between application servers and
associated external servers such as media servers.
</t>
<texttable title="RFC6230 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>cfw-id </c><c>Not Applicable </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6364 - SDP Elements for FEC Framework">
<t>
<xref target="RFC6364">RFC6364</xref> specifies the use of the
Session Description Protocol (SDP) to describe the parameters required
to signal the Forward Error Correction (FEC) Framework Configuration
Information between the sender(s) and receiver(s). This document
also provides examples that show the semantics for grouping multiple
source and repair flows together for the applications that simultaneously
use multiple instances of the FEC Framework.
</t>
<texttable title="RFC6364 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>fec-source-flow </c><c> </c><c>M </c>
<c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>fec-repair-flow </c><c> </c><c>M </c>
<c>SPECIA: </c>
<c> </c><c> </c><c> </c><c> </c>
<c>repair-window </c><c> </c><c>M </c>
<c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4796 - Content Attribute">
<t>
<xref target="RFC4796">RFC4796</xref> defines a new Session Description
Protocol (SDP) media-level attribute, 'content'. The 'content'
attribute defines the content of the media stream to a more detailed
level than the media description line. The sender of an SDP session
description can attach the 'content' attribute to one or more
media streams. The receiving application can then treat each media
stream differently (e.g., show it on a big or small screen) based on
its content.
</t>
<texttable title="RFC4796 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>content </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC3407 - SDP Simple Capability Declaration">
<t>
<xref target="RFC3407">RFC3407</xref> defines a set of
Session Description Protocol (SDP) attributes that enables SDP to
provide a minimal and backwards compatible capability declaration mechanism.
</t>
<texttable title="RFC3407 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>sqn </c><c>Not Impacted </c>
<c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>cdsc </c><c>Not Impacted. </c><c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>cpar </c><c>Refer to <xref target="encap"/> </c>
<c>B</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>cparmin </c><c>Refer to notes below </c>
<c>B</c><c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>cparmax </c><c>Refer to notes below </c>
<c>B</c><c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note"> Since the attributes (a=cparmin and a=cparmax) defines
minimum and maximum numerical values associated with the attributed
described in a=cpar, it is recommended to consult the document
defining the attribute for dealing under media stream multiplexing.
</t>
</section>
<section title="RFC6284 - Port Mapping between Unicast and Multicast RTP Sessions">
<t>
<xref target="RFC6284">RFC6284</xref> presents a port mapping solution
that allows RTP receivers to choose their own ports for an auxiliary
unicast session in RTP applications using both unicast and
multicast services. The solution provides protection against
denial-of-service or packet amplification attacks that could be used to
cause one or more RTP packets to be sent to a victim client
</t>
<texttable title="RFC6284 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>portmapping-req </c><c>Not recommended, if port mapping is
required by the application </c><c>M </c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6714 - MSRP-CEMA">
<t>
<xref target="RFC6714">RFC6714</xref> defines a
Message Session Relay Protocol (MSRP) extension,
Connection Establishment for Media Anchoring (CEMA).
Support of this extension is OPTIONAL. The extension allows
middle boxes to anchor the MSRP connection, without the need for
middle boxes to modify the MSRP messages; thus, it also enables secure
end-to-end MSRP communication in networks where such middle boxes are
deployed. This document also defines a Session Description Protocol
(SDP) attribute, 'msrp-cema', that MSRP endpoints use to indicate
support of the CEMA extension.
</t>
<texttable title="RFC6714 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>msrp-cema </c><c>Not Impacted </c><c>M </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4583 - SDP Format for BFCP Streams">
<t>
<xref target="RFC4583">RFC4583</xref> document specifies how to describe
Binary Floor Control Protocol (BFCP) streams in Session Description Protocol (SDP)
descriptions. User agents using the offer/answer model to establish BFCP streams
use this format in their offers and answers
</t>
<texttable title="RFC4583 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>floorctrl </c>
<c>Must be repeated across all the multiplexed m=lines </c>
<c>M </c><c>IDENTICAL </c><c> </c><c> </c>
<c> </c><c> </c>
<c>confid </c><c>Not Impacted </c><c>M </c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>userid </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>floorid </c>
<c>The floorid MUST be globally unique </c>
<c>M </c><c>NORMAL </c><c> </c><c> </c>
<c> </c><c> </c>
</texttable>
</section>
<section title="RFC5547 - SDP Offer/Answer for File Transfer">
<t>
<xref target="RFC5547">RFC5547</xref> provides a mechanism to negotiate
the transfer of one or more files between two endpoints by using
the Session Description Protocol (SDP) offer/answer model specified
in <xref target="RFC3264"/>.
</t>
<texttable title="RFC5547 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>file-selector </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>file-transfer-id </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c> file-disposition </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c> file-date </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c> file-iconfile-range </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6489 - SDP and RTP Media Loopback Extension">
<t>
<xref target="MEDIA_LOOPBACK"></xref> adds new SDP media types and
attributes, which enable establishment of media sessions where the
media is looped back to the transmitter. Such media sessions will
serve as monitoring and troubleshooting tools by providing the
means for measurement of more advanced VoIP, Real-time Text and
Video over IP performance metrics.
</t>
<texttable title="An Extension to the Session Description Protocol (SDP)
and Real-time Transport Protocol (RTP) for Media Loopback">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>loopback rtp-pkt-loopback </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>loopback rtp-media-loopback </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>loopback-source </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>loopback-mirror </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5760 - RTCP with Unicast Feedback ">
<t>
<xref target="RFC5760">RFC5760</xref> specifies an extension to the Real-time Transport
Control Protocol (RTCP) to use unicast feedback to a multicast
sender. The proposed extension is useful for single-source multicast
sessions such as Source-Specific Multicast (SSM) communication where
the traditional model of many-to-many group communication is either
not available or not desired.
</t>
<texttable title="RFC5760 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rtcp-unicast </c><c>The attribute MUST be reported across all
m=lines multiplexed </c><c>M</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC3611 - RTCP XR">
<t>
<xref target="RFC3611">RFC3611</xref> defines the Extended Report (XR) packet type for the
RTP Control Protocol (RTCP), and defines how the use of XR packets
can be signaled by an application if it employs the Session
Description Protocol (SDP).
</t>
<texttable title="RFC3611 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rtcp-xr </c><c>Not Impacted </c><c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5939 - SDP Capability Negotiation">
<t>
<xref target="RFC5939">RFC5939</xref> defines a general SDP
Capability Negotiation framework. It also specifies how to provide
attributes and transport protocols as capabilities and negotiate them using the framework.
Extensions for other types of capabilities (e.g., media types and media formats)
may be provided in other documents.
</t>
<texttable title="RFC5939 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>pcfg </c><c>Refer to section <xref target="encap"/> </c>
<c>M</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>acfg </c><c>Refer to section <xref target="encap"/> </c><c>M</c>
<c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>csup </c><c>Not Impacted </c><c>B</c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>creq </c><c>Not Impacted </c><c>B</c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>acap </c><c>Refer to section <xref target="encap"/> </c><c>B</c>
<c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>tcap </c><c>Refer to section <xref target="encap"/> </c>
<c>B</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6871- SDP Media Capabilities Negotiation">
<t>
Session Description Protocol (SDP) capability negotiation provides a
general framework for indicating and negotiating capabilities in SDP.
The base framework defines only capabilities for negotiating
transport protocols and attributes. <xref target="RFC6871"></xref>
extends the framework by defining media capabilities that can be used to
negotiate media types and their associated parameters.
</t>
<texttable title="Session Description Protocol (SDP) Media Capabilities Negotiation">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rmcap </c><c>Refer to section <xref target="encap"/> </c>
<c>B</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>omcap </c><c>Refer to section <xref target="encap"/> </c>
<c>B</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>mfcap </c><c>Refer to section <xref target="encap"/> </c>
<c>B</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>mscap </c><c>Refer to section <xref target="encap"/> </c>
<c>B</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>lcfg </c><c>Not Impacted </c>
<c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>sescap </c><c>Refer to section <xref target="encap"/> </c>
<c>S</c><c>INHERIT </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4567 - Key Management Extensions for SDP and RTSP">
<t>
<xref target="RFC4567">RFC4567</xref> defines general extensions for Session Description
Protocol (SDP) and Real Time Streaming Protocol (RTSP) to carry
messages, as specified by a key management protocol, in order to
secure the media. These extensions are presented as a framework, to
be used by one or more key management protocols. As such, their use
is meaningful only when complemented by an appropriate key management
protocol.
</t>
<texttable title="RFC4567 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>key-mgmt </c><c>Key management protocol MUST be identical
across all the m=lines </c><c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4572 - Comedia over TLS in SDP">
<t>
<xref target="RFC4572">RFC4572</xref> specifies how to establish
secure connection-oriented media transport sessions over the
Transport Layer Security (TLS) protocol using the Session Description Protocol (SDP).
It defines a new SDP protocol identifier, 'TCP/TLS'. It also defines the syntax
and semantics for an SDP 'fingerprint' attribute that identifies the
certificate that will be presented for the TLS session. This
mechanism allows media transport over TLS connections to be
established securely, so long as the integrity of session
descriptions is assured.
</t>
<texttable title="RFC4572 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>fingerprint </c><c>Fingerprint value from the m=line defining the
underlying transport is chosen </c><c>B</c><c>TRANSPORT </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4570 - SDP Source Filters">
<t>
<xref target="RFC4570">RFC4570</xref> describes how to adapt the
Session Description Protocol (SDP) to express one or more source addresses
as a source filter for one or more destination "connection" addresses.
It defines the syntax and semantics for an SDP "source-filter" attribute that may
reference either IPv4 or IPv6 address(es) as either an inclusive or
exclusive source list for either multicast or unicast destinations.
In particular, an inclusive source-filter can be used to specify a
Source-Specific Multicast (SSM) session
</t>
<texttable title="RFC4570 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>source-filter </c><c>The attribute MUST be repeated across all
m=lines multiplexed </c><c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6128 - RTCP Port for Multicast Sessions">
<t>
The Session Description Protocol (SDP) has an attribute that allows
RTP applications to specify an address and a port associated with the
RTP Control Protocol (RTCP) traffic. In RTP-based source-specific
multicast (SSM) sessions, the same attribute is used to designate the
address and the RTCP port of the Feedback Target in the SDP
description. However, the RTCP port associated with the SSM session
itself cannot be specified by the same attribute to avoid ambiguity,
and thus, is required to be derived from the "m=" line of the media
description. Deriving the RTCP port from the "m=" line imposes an
unnecessary restriction. <xref target="RFC6128">RFC6128</xref>
removes this restriction by introducing a new SDP attribute.
</t>
<texttable title="RFC6128 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>multicast-rtcp </c><c>Multicast RTCP port MUST be
identical across all the m=lines </c><c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6189 - ZRTP">
<t>
<xref target="RFC6189">RFC6189</xref> defines ZRTP, a protocol for media path Diffie-Hellman
exchange to agree on a session key and parameters for establishing
unicast Secure Real-time Transport Protocol (SRTP) sessions for Voice
over IP (VoIP) applications.
</t>
<texttable title="RFC6189 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>zrtp-hash </c><c>Complicates if all the m=lines are not
authenticated as given in the example below </c><c>M</c>
<c>NOT RECOMMENDED </c><c> </c><c> </c><c> </c><c> </c>
</texttable>
<t>
Example: Multiplexing media descriptions having attribute zrtp-hash defined
with the media descriptions lacking it, would either complicate the handling of
multiplexed stream or fail multiplexing.
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=bob 2890844527 2890844527 IN IP4 client.biloxi.example.com
s=
c=IN IP4 client.biloxi.example.com
t=0 0
m=audio 3456 RTP/AVP 97
a=rtpmap:97 iLBC/8000
<allOneLine>
a=zrtp-hash:1.10 fe30efd02423cb054e50efd0248742ac7a52c8f91bc2
df881ae642c371ba46df
</allOneLine>
m=video 34567 RTP/AVP 31
a=rtpmap:31 H261/90000
]]></artwork>
</figure>
</t>
</section>
<section title="RFC4145 - Connection-Oriented Media ">
<t>
<xref target="RFC4145">RFC4145</xref> describes how to express media
transport over TCP using the Session Description Protocol (SDP).
It defines the SDP 'TCP' protocol identifier, the SDP 'setup' attribute,
which describes the connection setup procedure, and the SDP 'connection'
attribute, which handles connection reestablishment.
</t>
<texttable title="RFC4145 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>setup </c><c>MUST be identical across all m=lines </c>
<c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>connection </c><c>MUST be identical across all m=lines </c>
<c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5159 - OMA BCAST SDP Attributes">
<t>
<xref target="RFC5159">RFC5159</xref> provides descriptions of Session Description Protocol
(SDP) attributes used by the Open Mobile Alliance's Broadcast Service
and Content Protection specification.
</t>
<texttable title="RFC5159 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>bcastversion </c><c>Not Impacted </c>
<c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>stkmstream </c><c>Not Impacted </c>
<c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>SRTPAuthentication </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>SRTPROCTxRate </c><c>Not Impacted </c>
<c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6193 - Media Description for IKE in SDP">
<t>
<xref target="RFC6193">RFC6193</xref> specifies how to establish a media session that
represents a virtual private network using the Session Initiation
Protocol for the purpose of on-demand media/application sharing
between peers. It extends the protocol identifier of the Session
Description Protocol (SDP) so that it can negotiate use of the
Internet Key Exchange Protocol (IKE) for media sessions in the SDP
offer/answer model.
</t>
<texttable title="RFC6193 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>ike-setup </c><c>Attribute MUST be identical
across all the m=lines </c><c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>psk-fingerprint </c><c>Attribute MUST be identical
across all the m=lines </c><c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ike-esp </c><c>Attribute MUST be identical
across all the m=lines </c><c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ike-esp-udpencap </c><c>Attribute MUST be identical
across all the m=lines </c><c>B</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note"> With the above SDP constraints, a session multiplexed with
multiple m=lines will use only one IPSec association for all of the m= lines.
</t>
</section>
<section title="RFC6064 - SDP and RTSP Extensions for 3GPP">
<t>
The Packet-switched Streaming Service (PSS) and the Multimedia
Broadcast/Multicast Service (MBMS) defined by 3GPP use the Session
Description Protocol (SDP) and Real Time Streaming Protocol (RTSP)
with some extensions. <xref target="RFC6064">RFC6064</xref>
provides information about these extensions and registers the RTSP and
SDP extensions with IANA.
</t>
<texttable title="RFC6064 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>X-predecbufsize </c><c>Refer to notes below </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>X-initpredecbufperiod </c><c>Refer to notes below </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>X-initpostdecbufperiod </c><c>Refer to notes below </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>X-decbyterate</c><c>Refer to notes below </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3gpp-videopostdecbufsize </c><c>Refer to notes below </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>framesize</c><c>The attribute value must be same
for a given codec configuration </c><c>M</c>
<c>IDENTICAL-PER-PT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-Integrity-Key </c><c>Refer to notes below </c><c>S</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-SRTP-Config </c><c>Refer to notes below </c><c>M</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>alt,alt-default-id </c><c>Refer to notes below </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>alt-group </c><c>Refer to notes below </c><c>M</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-Adaptation-Support </c><c>Refer to notes below </c><c>M</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-Asset-Informatio </c><c>Refer to notes below </c><c>B</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>mbms-mode </c><c>Refer to notes below </c><c>B</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>mbms-flowid </c><c>MRefer to notes below </c><c>M</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>mbms-repair </c><c>Refer to notes below </c><c>B</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Corruption duration </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Rebuffering duration </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Initial buffering duration </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Successive loss of RTP packets </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Frame rate deviation </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Jitter duration </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Content Switch Time </c>
<c>Refer to notes below </c><c>B</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Average Codec Bitrat </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Codec Information </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>3GPP-QoE-Metrics:Buffer Status </c>
<c>Refer to notes below </c><c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Notes">
<xref target="RFC6064"/> defines SDP attributes that are applicable in
the declarative usage of SDP alone. For purposes of this document, only the Offer/Answer
usage of SDP is considered as mandated by <xref target="I-D.ietf-mmusic-sdp-bundle-negotiation"></xref>.
</t>
</section>
<section title="RFC3108 - ATM SDP">
<t>
<xref target="RFC3108">RFC3108</xref> describes conventions for using
the Session Description Protocol (SDP) described for controlling
ATM Bearer Connections, and any associated ATM Adaptation Layer (AAL)
</t>
<texttable title="RFC3108 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>aalType </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>eecid </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aalType </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>capability </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>qosClass </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>bcob </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>stc </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>upcc </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>atmQOSparms </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>atmTrfcDesc </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>abrParms </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>abrSetup </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>bearerType </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>lij </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>anycast </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>cache </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>bearerSigIE </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aalApp </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>cbrRate </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>sbc </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>clkrec </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>fec </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>prtfl </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>structure </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>cpsSDUsize </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aal2CPS </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aal2CPSSDUrate </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aal2sscs3661unassured </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aal2sscs3661assured </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aal2sscs3662 </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>aal5sscop </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>atmmap </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>silenceSupp </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>ecan </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>gc </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>profileDesc </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>vsel </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>dsel </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>fsel </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>onewaySel </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>codecconfig </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>isup_usi </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>isup_usi </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c>chain </c><c>Not Impacted</c><c>B </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note">RFC3108 describes conventions for using the
Session Description Protocol (SDP) for characterizing ATM bearer
connections using an AAL1, AAL2 or AAL5 adaptation layers. For AAL1,
AAL2 and AAL5, bearer connections can be used to transport single
media streams. In addition, for AAL1 and AAL2, multiple media streams
may be multiplexed into a bearer connection. For all adaptation types
(AAL1, AAL2 and AAL5), bearer connections may be bundled into a
single media group. In all cases addressed by RFC3108, a real-time
media stream (voice, video, voiceband data, pseudo-wire and others) or
a multiplex of media streams is mapped directly into an ATM connection.
RFC3108 does not address cases where ATM serves as a
low-level transport pipe for IP packets which in turn may carry one
or more real-time (e.g. VoIP) media sessions with a life-cycle
different from that of the underlying ATM transport.
</t>
</section>
<section title="3GPP TS 24.182">
<t>
<xref target="R3GPPTS24.182">3GPP TS 24.182</xref> specifies IP multimedia subsystem Custom Alerting tones
</t>
<texttable title="3GPP TS 24.182 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>g.3gpp.cat </c><c>Usage defined for the IP Multimedia Subsystem </c>
<c>M</c><c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="3GPP TS 24.183">
<t>
<xref target="R3GPPTS24.183">3GPP TS 24.183</xref>specifies IP multimedia
subsystem Custom Ringing Signal
</t>
<texttable title="3GPP TS 24.183 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>g.3gpp.crs </c><c>Usage defined for the IP Multimedia Subsystem </c>
<c>M</c><c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="3GPP TS 24.229">
<t>
<xref target="R3GPPTS24.229">3GPP TS 24.229</xref>IP multimedia call control
protocol based on Session Initial protocol and Session Description Protocol.
</t>
<texttable title="3GPP TS 24.229 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>secondary-realm </c><c>Per media-level attribute MUST be used per
underlying transport </c><c>M</c><c>TRANSPORT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>visited-realm </c><c>Per media-level attribute MUST be used per
underlying transport </c><c>M</c><c>TRANSPORT </c><c> </c>
<c> </c><c> </c><c> </c>
<c>omr-m-cksum </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>omr-s-cksum </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>omr-m-att </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>omr-s-bw </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>omr-s-bw </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>omr-m-att </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>omr-codecs </c><c>Not Impacted </c><c>M</c>
<c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="ITU T.38">
<t>
ITU T.38<xref target="T.38"></xref> defines procedures for real-time Group 3
facsimile communications over IP networks.
</t>
<texttable title="Historic Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>T38FaxVersion </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38MaxBitRate </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38FaxFillBitRemoval </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38FaxTranscodingMMR </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38FaxTranscodingJBIG </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38FaxRateManagement </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38FaxMaxBuffer </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38FaxMaxDatagram </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>T38FaxUdpEC </c><c>Not Impacted </c><c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t hangText="Note"> The ITU T.38 attributes are clearly unaffected by multiplexing and
are specific to the working of the fax protocol itself.</t>
</section>
<section title="ITU-T H.248.15">
<t>
ITU-T H.248.15 <xref target="H.248.15"></xref> defines Gateway Control Protocol
SDP H.248 package attribute
</t>
<texttable title="Historic Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>h248item </c><c>It is also only applicable for signaling the inclusion of
H.248 extension packages to a gateway via the local and remote descriptors. The
attribute itself is unaffected by multiplexing, but the packaged referenced in a
specific use of the attribute may be impacted. Further analysis of each package
is needed to determine if there is an issue. This is only a concern in
environments using a decomposed server/gateway with H.248 signaled between them.
The ITU-T will need to do further analysis of various packages when they specify
how to signal the use of multiplexing to a gateway. </c>
<c>B</c><c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4975 - The Message Session Relay Protocol">
<t>
<xref target="RFC4975">RFC4975</xref> the Message Session Relay Protocol, a protocol for transmitting a
series of related instant messages in the context of a session. Message sessions
are treated like any other media stream when set up via a rendezvous or session creation
protocol such as the Session Initiation Protocol.
</t>
<texttable title="RFC4975 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>accept-types </c><c>Not Impacted </c>
<c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>accept-wrapped-types </c><c>Not Impacted </c>
<c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>max-size </c><c>Not Impacted </c>
<c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>path </c><c>Not Impacted </c>
<c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="Historical">
<t>
This section specifies analysis for the attributes that are included for historic
usage alone by the <xref target="IANA"></xref>.
</t>
<texttable title="Unknowns Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rtpred1 </c><c>Historic attributes. </c>
<c>Not-Applcable</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>rtpred2 </c><c>Historic attributes. </c>
<c>Not-Applcable</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>PSCid </c><c>Not Applicable </c>
<c>Not-Applcable</c><c>TBD </c>
<c> </c><c> </c><c> </c><c> </c>
<c>bc_service </c><c>Not Applicable </c>
<c>Not-Applcable</c><c>TBD </c>
<c> </c><c> </c><c> </c><c> </c>
<c>bc_program </c><c>Not Applicable </c>
<c>Not-Applcable</c><c>TBD </c>
<c> </c><c> </c><c> </c><c> </c>
<c>bc_service_package </c><c>Not Applicable </c>
<c>Not-Applcable</c><c>TBD </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
</section>
<section title="bwtype Attribute Analysis" anchor="SecbwtypeAnalysis" >
<t>
This section specifies handling of specific bandwidth attributes when
used in multiplexing scenarios.
</t>
<section title="RFC4566 - SDP: Session Description Protocol">
<texttable title="RFC4566 bwtype Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>bwtype:CT </c><c>Aggregate bandwidth for the conference </c>
<c>S</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>bwtype:AS </c><c> As a session attribute, it specifies the session
aggregate unless media-level b=RR and/or b=RS attributes are used.
Under this interpretation the multiplexing scheme has no impact and thus NORMAL category applies. </c>
<c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>bwtype:AS </c><c> For the media level usage,the aggregate of individual bandwidth values is considered. </c><c>B</c>
<c>SUM </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC3556 - SDP Bandwidth Modifiers for RTCP Bandwidth">
<t>
<xref target="RFC3556">RFC3556</xref> defines an extension to the
Session Description Protocol (SDP) to specify two additional modifiers
for the bandwidth attribute. These modifiers may be used to specify
the bandwidth allowed for RTP Control Protocol (RTCP) packets in a Real-time
Transport Protocol (RTP) session
</t>
<texttable title="RFC3556 bwtype Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>bwtype:RS </c><c>Session level usage represents session aggregate and
media level usage indicates SUM of the individual values while multiplexing </c>
<c>B</c><c>NORMAL,SUM</c>
<c> </c><c> </c><c> </c><c> </c>
<c>bwtype:RR </c><c>Session level usage represents session aggregate and
media level usage indicates SUM of the individual values while multiplexing </c>
<c>B</c><c>NORMAL,SUM </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC3890 - Bandwidth Modifier for SDP">
<t>
<xref target="RFC3890">RFC3890</xref> defines a Session Description Protocol (SDP)
Transport Independent Application Specific Maximum (TIAS) bandwidth modifier
that does not include transport overhead; instead an additional
packet rate attribute is defined. The transport independent bit-rate
value together with the maximum packet rate can then be used to
calculate the real bit-rate over the transport actually used.
</t>
<texttable title="RFC3890 bwtype Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>bwtype:TIAS </c><c>The usage of TIAS is not clearly defined Offer/Answer
usage. </c><c>B</c><c>SPECIAL </c><c> </c><c> </c>
<c> </c><c> </c>
<c>maxprate </c><c>The usage of TIAS and maxprate is not well defined under
multiplexing </c><c>B</c><c>SPECIAL </c><c> </c><c> </c>
<c> </c><c> </c>
</texttable>
<t hangText="Note"> The intention of TIAS is that the media level bit-rate is
multiplied with the known per-packet overhead for the selected transport and
the maxprate value to determine the worst case bit-rate from the transport
to more accurately capture the required usage.
Summing TIAS values independently across m=lines and multiplying the
computed sum with maxprate and the per-packet overhead would inflate the
value significantly. Instead performing multiplication and adding the
individual values is a more appropriate usage. This still ignores the
fact that this is a send side declaration, and not intended for
receiver negotiation.
</t>
</section>
</section>
<section title="rtcp-fb Attribute Analysis" anchor="SecrtcpfbAnalysis">
<t>
This section analyzes rtcp-fb SDP attributes <xref target="RTCP-FB"></xref>.
</t>
<section title="RFC4585 - RTP/AVPF">
<t>
<xref target="RFC4585">RFC4585</xref> defines an extension to the
Audio-visual Profile (AVP) that enables receivers to provide, statistically,
more immediate feedback to the senders and thus allows for short-term
adaptation and efficient feedback-based repair mechanisms to be implemented.
</t>
<texttable title="RFC4585 Attribute Analysis">
<ttcol align='left'>Attr Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>ack rpsi </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ack app </c>
<c>Feedback parameters MUST be handled in the app specific
way when multiplexed</c>
<c>M</c><c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>nack </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>nack pli </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>nack sli </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>nack rpsi </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>nack app </c>
<c>Feedback parameters MUST be handled in the app specific
way when multiplexed</c>
<c>M</c><c>SPECIAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>trr-int </c>
<c>This attribute applies to RTP Session as a whole</c>
<c>M</c><c>IDENTICAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5104 - Codec Control Messages in AVPF">
<t>
<xref target="RFC5104">RFC5104</xref> specifies a few extensions to
the messages defined in the Audio-Visual Profile with Feedback (AVPF).
They are helpful primarily in conversational multimedia scenarios
where centralized multipoint functionalities are in use.
However, some are also usable in smaller multicast environments
and point-to-point calls.
</t>
<texttable title="RFC5104 Attribute Analysis">
<ttcol align='left'>Attr Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>ccm </c><c>Not Impacted</c><c>M</c><c>Normal </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6285 - Unicast-Based RAMS">
<texttable title="RFC6285 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>nack rai </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6679 - ECN for RTP over UDP/IP">
<t>
<xref target="RFC6679">RFC6679</xref> specifies how Explicit Congestion Notification (ECN) can be
used with the Real-time Transport Protocol (RTP) running over UDP,
using the RTP Control Protocol (RTCP) as a feedback mechanism. It
defines a new RTCP Extended Report (XR) block for periodic ECN
feedback, a new RTCP transport feedback message for timely reporting
of congestion events, and a Session Traversal Utilities for NAT
(STUN) extension used in the optional initialization method using
Interactive Connectivity Establishment (ICE)
</t>
<texttable title="RFC6679 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>ecn-capable-rtp </c><c>ECN markup are enabled at the RTP Session level </c>
<c>M </c><c>IDENTICAL </c><c> </c><c> </c><c> </c><c> </c>
<c>nack ecn </c><c>This attribute enables ECN at the RTP session level </c>
<c>M </c><c>IDENTICAL </c><c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC6642 - Third-Party Loss Report">
<t>
In a large RTP session using the RTP Control Protocol (RTCP) feedback
mechanism defined in RFC 4585 <xref target="RFC4585"></xref>,
a feedback target may experience transient overload if some event
causes a large number of receivers to send feedback at once.
This overload is usually avoided by ensuring that feedback reports
are forwarded to all receivers, allowing them to avoid sending duplicate
feedback reports. However, there are cases where it is not recommended to
forward feedback reports, and this may allow feedback implosion.
RFC6642 <xref target="RFC6642"></xref> memo discusses these cases and defines a
new RTCP Third-Party Loss Report that can be used to inform receivers that the
feedback target is aware of some loss event, allowing them to suppress feedback.
Associated Session Description Protocol (SDP) signaling is also defined.
</t>
<texttable title="RFC6642 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>nack tllei </c><c>Not Impacted </c><c>M </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>nack pslei </c><c>Not Impacted </c><c>M </c>
<c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5104 - Codec Control Messages in AVPF">
<texttable title="RFC5104 Attribute Analysis">
<ttcol align='left'>Attr Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>ccm fir </c><c>Not Impacted</c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ccm tmmbr </c><c>Not Impacted</c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ccm tstr </c><c>Not Impacted</c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>ccm vbcm </c><c>Not Impacted</c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
</section>
<section title="group Attribute Analysis"
anchor="SecgroupAnalysis">
<t>
This section analyzes SDP "group" semantics <xref target="GROUP-SEM"></xref>.
</t>
<section title="RFC5888 - SDP Grouping Framework">
<t>
<xref target="RFC5888">RFC5888</xref> defines a framework
to group "m" lines in the Session Description Protocol (SDP)
for different purposes.
</t>
<texttable title="RFC5888 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>group:LS </c><c>Not Impacted </c><c>S </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>group:FID </c><c>Not Impacted </c><c>S </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC3524 - Mapping Media Streams to Resource Reservation Flows">
<t>
<xref target="RFC3524">RFC3524</xref> defines an extension to the
Session Description Protocol (SDP) grouping framework. It allows requesting a
group of media streams to be mapped into a single resource reservation flow.
The SDP syntax needed is defined, as well as a new "semantics"
attribute called Single Reservation Flow (SRF).
</t>
<texttable title="RFC3524 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>group:SRF </c><c>Not Impacted </c><c>S </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC4091 - ANAT Semantics">
<t>
<xref target="RFC4091">RFC4091</xref> defines the
Alternative Network Address Types (ANAT) semantics for the
Session Description Protocol (SDP) grouping framework. The
ANAT semantics allow alternative types of network addresses to
establish a particular media stream.
</t>
<texttable title="RFC4091 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>group:ANAT </c><c>ANAT semantics is obseleted </c><c>S </c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5956 - FEC Grouping Semantics in SDP">
<t>
<xref target="RFC5956">RFC5956</xref> defines the semantics for
grouping the associated source and FEC-based (Forward Error Correction)
repair flows in the Session Description Protocol (SDP). The semantics
defined in the document are to be used with the SDP Grouping Framework (RFC 5888).
These semantics allow the description of grouping relationships
between the source and repair flows when one or more source and/or
repair flows are associated in the same group, and they provide
support for additive repair flows. SSRC-level (Synchronization
Source) grouping semantics are also defined in this document for
Real-time Transport Protocol (RTP) streams using SSRC multiplexing.
</t>
<texttable title="RFC5956 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>group:FEC-FR </c><c>Not Impacted </c><c>S </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
<section title="RFC5583 - Signaling Media Decoding Dependency in SDP">
<t>
<xref target="RFC5583">RFC5583</xref> 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>
<texttable title="RFC5583 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>depend lay </c><c>The attribute value must be same
for a given codec configuration </c><c>M</c>
<c>IDENTICAL-PER-PT </c>
<c> </c><c> </c><c> </c><c> </c>
<c>depend mdc </c><c>The attribute value must be same
for a given codec configuration </c><c>M</c>
<c>IDENTICAL-PER-PT </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t>
The usage of identical Payload Type values across multiplexed m=lines is described in
<xref target="I-D.ietf-mmusic-sdp-bundle-negotiation"></xref>.
</t>
</section>
</section>
<section title="ssrc-group Attribute Analysis"
anchor="SecssrcgroupAnalysis">
<t>
This section analyzes "ssrc-group" semantics <xref target="SSRC-GROUP"></xref>.
</t>
<section title="RFC5576 - Source-Specific SDP Attributes">
<texttable title="RFC5576 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>FID </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>FEC </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>FEC-FR </c><c>Not Impacted </c><c>M</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
</section>
<section title="QoS Mechanism Token Analysis"
anchor="SecqostokenAnalysis">
<t>
This section analyzes QoS tokes specified with SDP<xref target="QOS"></xref>.
</t>
<section title="RFC5432 - QoS Mechanism Selection in SDP">
<texttable title="RFC5432 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>rsvp </c><c>Not Impacted, since QOS mechanisms are applied per flow. </c>
<c>B</c><c>NORMAL </c><c> </c><c> </c><c> </c><c> </c>
<c>nsis </c><c>Not Impacted, since QOS mechanisms are applied per flow. </c>
<c>B</c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
</section>
<section title="k= Attribute Analysis" anchor="SeckAnalysis">
<section title="RFC4566 SDP: Session Description Protocol">
<texttable title="RFC4566 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>k= </c><c>It is NOT recommended to use this attribute </c><c>S</c>
<c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
</section>
<section title="content Atribute Analysis" anchor="SeccontentAnalysis">
<section title="RFC4796">
<texttable title="RFC4796 Attribute Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>content:slides </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>content:speaker </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>content:main </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>content:sl </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
<c>content:alt </c><c>Not Impacted </c><c>M </c><c>NORMAL </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
</section>
</section>
<section anchor="sec-pay" title="Payload Formats">
<section title="RFC5109 - RTP Payload Format for Generic FEC">
<t>
<xref target="RFC5109">RFC5109</xref> describes a payload format for
generic Forward Error Correction (FEC) for media data encapsulated in
RTP. It is based on the exclusive-or (parity) operation. The payload
format allows end systems to apply protection using various protection
lengths and levels, in addition to using various protection group
sizes to adapt to different media and channel characteristics. It
enables complete recovery of the protected packets or partial recovery
of the critical parts of the payload depending on the packet loss
situation.
</t>
<texttable title="RFC5109 Payload Format Analysis">
<ttcol align='left'>Name</ttcol>
<ttcol align='left'>Notes</ttcol>
<ttcol align='left'>Level</ttcol>
<ttcol align='left'>Category</ttcol>
<c>audio/ulpfec </c><c>Not recommended for multiplexing due to reuse of SSRCs </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>video/ulpfec </c><c>Not recommended for multiplexing due to reuse of SSRCs </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>text/ulpfec </c><c>Not recommended for multiplexing due to reuse of SSRCs </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
<c>application/ulpfec </c><c>Not recommended for multiplexing due to reuse of SSRCs </c>
<c>M</c><c>NOT RECOMMENDED </c>
<c> </c><c> </c><c> </c><c> </c>
</texttable>
<t> Draft draft-lennox-payload-ulp-ssrc-mux proposes a simple fix to
make it possible to use ULP with multiplexing and ULP is allowed when
used with that. </t>
</section>
</section>
<section anchor="dscp-mux" title="Multiplexing Media Streams and DSCP Markings">
<t>
Note: This section does not yet have WG consensus but is included
as a proposal to the WG. There are two options being proposed, A
and B. The authors suggest A.
</t>
<section title="Option A">
<t>
This section provides two rules for multiplexing multiple media streams
with DSCP markings over a single 5-tuple.
<list>
<t>
Rule 1: Media Streams with markings from different service classes
MUST NOT be multiplexed. For example, a media stream with DSCP Marking EF
MUST NOT be multiplexed with a media stream marked with AF class.
Likewise, a media stream with DSCP marking AF3x MUST NOT be multiplexed
with a media stream marked with AF4x.
</t>
<t>
Rule 2: Media Streams that belong to the same service class, even with
different drop precedence, MAY be multiplexed. Thus media streams that all
belong to the EF group or all that belong to the AF4X class can be multiplexed.
</t>
</list>
</t>
<t>
For WebRTC applications following the advice in <xref target="I-D.dhesikan-tsvwg-rtcweb-qos"/>,
the above rules end up allowing the audio and video to be
multiplexed in many, but not all, cases.
</t>
</section>
<section title="Option B">
<t>
Media Streams MAY be multiplexed regardless of what the setting of the DSCP Per Hop Behavior
group (PHB).
</t>
</section>
</section>
<section anchor="encap" title="Multiplexing Considerations for Encapsulating Attributes">
<t>
This sections deals with recommendations for defining the multiplexing characteristics
of the SDP attributes that encapsulate other SDP attributes/parameters. Such
attributes as of today, for example, are defined in [RFC3407], [RFC5939] and [RFC6871]
as part of a generic framework for indicating and negotiating transport, media and
media format related capabilities in the SDP.
</t>
<t>
The behavior of such attributes under multiplexing is in turn defined by the
multiplexing behavior of the attributes they encapsulate which are made known
once the Offer/Answer negotiation process is completed.
</t>
<section title="RFC3407 - cpar Attribute Analysis">
<t> RFC3407 capability parameter attribute (a=cpar) encapsulates b= (bandwidth) or an a= attribute. For bandwidth attribute encapsulation, the category SUM is inherited. For the case of a= attribute, the category corresponding to the SDP attribute being referenced is inherited.
</t>
<t>
<figure>
<artwork align="left" alt="" height="" name="" type="" width=""
xml:space="preserve"><![CDATA[
v=0
o=alice 2890844526 2890844527 IN IP4 host.atlanta.example.com
s=
c=IN IP4 host.atlanta.example.com
t=0 0
m=video 3456 RTP/AVP 100
a=rtpmap:100 VP8/90000
a=sqn: 0
a=cdsc: 1 video RTP/AVP 100
a=cpar: a=rtcp-mux
m=video 3456 RTP/AVP 101
a=rtpmap:101 VP8/90000
a=fmtp:100 max-fr=15;max-fs=1200
a=cdsc: 2 video RTP/AVP 101
a=cpar: a=rtcp-mux
]]></artwork>
</figure>
</t>
<t> In the above example ,the category IDENTICAL is inherited for the cpar
encapsulated rtcp-mux attribute.</t>
<t> </t>
</section>
<section title="RFC5939 Analysis">
<t>
<xref target="RFC5939"/> defines a general SDP capability negotiation framework. It also specifies how to provide transport protocols and SDP attributes as capabilities and negotiate them using the framework.
</t>
<t>
For this purpose, <xref target="RFC5939"/> defines the following
<list style="symbols">
<t>
A set of capabilities for the session and its associated media stream
components, supported by each side. The attribute ("a=acap") defines
how to list an attribute name and its associated value (if any) as a
capability. The attribute ("a=tcap") that defines how to list transport
protocols (e.g., "RTP/AVP") as capabilities.
</t>
<t>
A set of potential configurations indicating which combinations of
those capabilities can be used for the session and its associated
media stream components. Potential configurations are not ready
for use. Instead, they provide an alternative that may be used,
subject to further negotiation.
</t>
<t>
An actual configuration for the session and its associated media
stream components, that specifies which combinations of session
parameters and media stream components can be used currently and
with what parameters. Use of an actual configuration does not
require any further negotiation.
</t>
<t>
A negotiation process that takes the set of actual and potential
configurations (combinations of capabilities) as input and
provides the negotiated actual configurations as output.
</t>
</list>
</t>
<section title="Recommendations">
<t>
This section provides recommendations for entities generating and processing
SDP under the generic capability negotiation framework as defined in <xref target="RFC5939"/>
under the context of media stream multiplexing.
</t>
<t>
These recommendations are provided for the purposes of enabling the
Offerer to make sure that the generated potential configurations between the
multiplexed streams can (easily) be negotiated to be consistent between
those streams.
</t>
<section title="Recommendation-1: Transport Capability Analysis">
<t>
When a transport capability is proposed as a potential configuration under a
given media description, it is recommended that all the media descriptions
under multiplexing have the same potential configuration number for the
given transport capability.
</t>
<figure title="">
<artwork><![CDATA[
a=tcap:1 RTP/SAVPF
a=tcap:2 RTP/SAVP
a=group:BUNDLE audio video
m= audio
a=mid:audio
a=pcfg:1 t=1
a=pcfg:2
m= video
a=mid:video
a=pcfg:1 t=1
a=pcfg:2 t=2
]]></artwork>
</figure>
<t>
In the example above, the potential configurations that Offer
transport protocol capability of RTP/SAVPF has the same configuration
number "1" in both the audio and video media descriptions.
</t>
</section>
<section title="Recommendation-2: Attribute Capability Analysis">
<t>
For attribute capabilities which are offered as potential configurations
that encapsulate attributes whose value MUST be IDENTICAL under
multiplexing, it is recommended that all the media descriptions under
multiplexing have the same potential configuration number for the given
attribute capability.
</t>
<figure title="">
<artwork><![CDATA[
a=acap:1 a=rtcp-mux
a=acap:2 a=crypto:1 AES_CM_128_HMAC_SHA1_80
inline:EcGZiNWpFJhQXdspcl1ekcmVCNWpVLcfHAwJSoj|2^20|1:32
a=group:BUNDLE audio video
m= audio 49172 RTP/AVP 99
a=mid:audio
a=pcfg:1 a=1
a=pcfg:2
m= video 560024 RTP/AVP 100
a=mid:video
a=pcfg:1 a=1
a=pcfg:2 a=2
]]></artwork>
</figure>
<t>
In the example above, the potential configuration number 1
is repeated while referring to attribute capability a=rtcp-mux, since
the behavior is IDENTICAL for the attribute a=rtcp-mux under
multiplexing.
</t>
</section>
<section title="Recommendation-3: Sescap Attribute Analysis">
<t>
It is recommended that any bundled media descriptions/configurations are also acceptable combinations of media streams/configurations as specified by "sescap" attribute.
</t>
</section>
<section title="Recommendation-4: Capability Extension Attributes">
<t>
Since it is nearly impossible to define a generic mechanism for various
capability extensions , this document does't provide procedures for
dealing with the capability extension attributes. However, Section
<xref target="med-cap-analysis"/> provide analysis of media capability extension
attributes as defined in <xref target="RFC6871"/>.
</t>
</section>
</section>
</section>
<section title = "RFC6871 Analysis" anchor="med-cap-analysis">
<t>
<xref target="RFC6871"/> extends capability negotiation framework described in
<xref target="RFC5939"/> by defining media capabilities that can be used to indicate
and negotiate media types and their associated format parameters.
</t>
<t>
Building upon the analysis from the previous section, following recommendation is
provided for dealing with the attributes defined in <xref target="RFC6871"/> under
multiplexing
</t>
<section title="Recommendation-5: Attribute Capability Under Shared Payload Type">
<t>
For attribute capabilities which are offered as potential configurations
that encapsulate attributes whose value MUST be IDENTICAL-PER-PT under
multiplexing, it is recommended that all the media descriptions under
multiplexing have the same potential configuration number for the given
attribute capability
</t>
<t>
The attributes (a=rmcap, a=mfcap) follow the above recommendations under
mutliplexing
</t>
<figure title="">
<artwork><![CDATA[
v=0
o=- 25678 753849 IN IP4 192.0.2.1
s=
c=IN IP4 192.0.2.1
t=0 0
a=creq:med-v0
m=audio 54322 RTP/AVP 96
a=rtpmap:96 AMR-WB/16000/1
a=fmtp:96 mode-change-capability=1; max-red=220;
mode-set=0,2,4,7
a=rmcap:1,3 audio AMR-WB/16000/1
a=rmcap:2 audio AMR/8000/1
a=mfcap:1,2 mode-change-capability=1
a=mfcap:3 mode-change-capability=2
a=pcfg:1 m=1 pt=1:96
a=pcfg:2 m=2 pt=2:97
a=pcfg:3 m=3 pt=3:98
m=audio 54322 RTP/AVP 96
a=rtpmap:96 AMR-WB/16000/1
a=fmtp:96 mode-change-capability=1; max-red=220;
mode-set=0,2,4,7
a=rmcap:4 audio AMR/8000/1
a=rmcap:5 audio OPUS/48000/2
a=mfcap:5 minptime=40
a=mfcap:4 mode-change-capability=1
a=pcfg:1 m=4 pt=4:97
a=pcfg:4 m=5 pt=5:101
]]>
</artwork>
</figure>
<t>
In the example above, the potential configuration number 1
is repeated when referring to media and media format capability
used for the Payload Type 97. This implies that both the media
capability 2 and 4 along with their media format capabilities
MUST refer to the same Codec configuration , as per the definition
of IDENTICAL-PER-PT
</t>
</section>
</section>
<section title="Recommendation-6: Offer/Answer Negotiation Expectations">
<t>
For attributes encapsulated via "a=acap", "a=omcap", "a=mscap" capability attributes
and presented as part of potential/actual configurations during the Offer/Answer
negotiation prodecure, the negotiation MUST ensure that the multiplexing behavior of
these capabilities inherit from the behavior of the attribute being encapsulated.
</t>
<t>
Example 1: Below SDP example captures the following aspects.
<list style="symbols">
<t>
The Offerer offers audio and video streams with several different RTP profiles (AVP,
SAVP, SAVPF) as potential configurations.
</t>
<t>
Valid Answer that corresponds to the SDP answer where the Answerer accepts RTP/SAVPF as the default profile for both the media streams. In this scenario both the media streams can be successfully multiplexed.
</t>
<t>
Invalid Answer wherein the Answerer accepts the profile RTP/SAVPF for the audio stream and RTP/AVPF for the video stream. This scenario results in the failure of the multiplexing as defined in the section 7.2 of the BUNDLE specification [I-D.ietf-mmusic-sdp-bundle-negotiation].
</t>
</list>
</t>
<figure title="">
<artwork><![CDATA[
<Offer-SDP>
v=0
o=- 25678 753849 IN IP4 192.0.2.1
s=
t=0 0
c=IN IP4 192.0.2.1
m=audio 3456 RTP/AVP 98
a=tcap:1 RTP/SAVPF
a=rtpmap:98 OPUS/48000/2
a=pcfg:1 t=1
m=video 51372 RTP/AVP 101
a=rtpmap:101 H264/90000
a=tcap:2 RTP/SAVPF RTP/AVPF
a=pcfg:2 t=2|3
<Valid Answer>
v=0
o=- 24351 621814 IN IP4 192.0.2.2
s=
m=audio 3456 RTP/SAVPF 98
a=rtpmap:98 OPUS/48000/2
a=acfg:1 t=1
m=video 51372 RTP/SAVPF 101
a=rtpmap:101 H264/90000
a=acfg:2 t=2
<Invalid Answer>
v=0
o=- 24351 621814 IN IP4 192.0.2.2
s=
m=audio 3456 RTP/SAVPF 98
a=rtpmap:98 OPUS/48000/2
a=acfg:1 t=1
m=video 51372 RTP/AVPF 101
a=rtpmap:101 H264/90000
a=acfg:2 t=3]]>
</artwork>
</figure>
</section>
</section>
<section title="IANA Considerations">
<t>
IANA shall register categories from this specification by expanding the
Session Description Protocol (SDP) Parameters table with a column
listing categories against each SDP parameter.</t>
<figure>
<artwork align="center"><![CDATA[
+---------------------+
| Category |
+---------------------+
| NORMAL |
+---------------------+
| NOT RECOMMENDED |
+---------------------+
| IDENTICAL |
+---------------------+
| TRANSPORT |
+---------------------+
| INHERIT |
----------------------+
| IDENTICAL-PER-PT |
+---------------------+
| SPECIAL |
----------------------
]]></artwork>
</figure>
</section>
<section title="Security Considerations">
<t>
All the attributes which involve security key needs a careful review to
ensure two-time pad vulnerability is not created.
</t>
</section>
<section title="Acknowledgments">
<t>
I would like to thank Cullen Jennings for suggesting the categories,
contributing text and reviewing the draft. I would also link to
thank Magnus, Christer, Jonathan Lennox, Bo Burman,
and Dan on suggesting structural changes helping improve the document readability.
</t>
<t>
I would like also to thank following experts on their inputs and
reviews as listed - Flemming Andreasen(5.20,5.28,5.29,15), Rohan Mahy(5.45),
Eric Burger(5.22),Christian Huitema(5.13), Christer Holmberg(5.17,5.22,5.40,5.41),
Richard Ejzak (5.36,5.42,5.43,5.44), Colin Perkins(5.7,5.8),
Magnus westerlund(5.2,5.3,5.9,5.26, 5.27,6.1,6.2,6.3,8.3,7),
Roni Evens(5.12,5.27,8.4), Subha Dhesikan(5.5,12.1,14),
Dan Wing(5.6,5.11,5.30,5.34,5.37),
Ali C Begen(5.1,5.16,5.18,5.21,5.33,8.2,8.4,13.1),
Bo Burman (7.2,7.6), Charles Eckel(5.14,5.23,5.24,9.1,8.5),
Paul Kyzivat(5.24), Ian Johansson(5.15), Saravanan Shanmugham(5.10),
Paul E Jones(5.25), Rajesh Kumar(5.39), Jonathan Lennox(5.31,5,14,11.1),
Mo Zanaty(5.4,5.19,8.1,8.3,8.5,12.1), Christian Huitema (5.13),
Qin Wu (5.38 PM-Dir review).
</t>
</section>
<section title="Change Log">
<t>[RFC EDITOR NOTE: Please remove this section when publishing]</t>
<t>Changes from draft-ietf-mmusic-sdp-mux-attributes-01
<list style="symbols">
<t>
Updated section 15 to provide detailed recommendation on dealing
with encapsulating attributes. Also updated sections 5.20,
5.28, 5.29 to refer to Section 15.
</t>
<t>
Added new categories IDENTICAL-PER-PT and INHERIT
</t>
<t>
Updated Sections 16 to add the new categories.
</t>
<t>
Updated Sections 5.1, 5.14, 5.15, 5.38, 8.5 to reflect the
category IDENTICAL-PER-PT.
</t>
<t>
Reformatted section 4 to add individual categories to their
own sections.
</t>
</list>
</t>
<t>Changes from draft-ietf-mmusic-sdp-mux-attributes-00
<list style="symbols">
<t>
Added Section 15 to provide recommendations on multiplexing
SDP encapsulating attributes. Also updated sections 5.20,
5.28, 5.29 to refer to Section 15.
</t>
<t>
Updated Section 5.38 to incorporate PM-dir review inputs from
Qin Wu
</t>
<t>
Updated Sections 5.2,5.14,8.5 to refer to BUNDLE draft for more clarity.
</t>
<t>
Fixed few nits regarding sentence clarity and fill-in the NOTES
section where information was lacking.
</t>
</list>
</t>
<t>Changes from draft-nandakumar-mmusic-mux-attributes-05
<list style="symbols">
<t>
Renamed the document to be a WG document.
</t>
<t>
Added Section 14.
</t>
<t>
Updated Open Issues based on IETF88 discussions.
</t>
</list>
</t>
<t>Changes from draft-nandakumar-mmusic-mux-attributes-04
<list style="symbols">
<t>
Added few OPEN ISSUES that needs to be discussed.
</t>
<t>
Updated sections 5.10,5.23,5,24,5,25,7.2,9.1,5.12,5.27,8.4,
5.44,5.11,5.4,5.19,10.1,10.5,5.21,10.4,15.1
</t>
<t>
Updated Table Column name Current to Level and improved TRANSPORT
category explanation on suggestions form Dan Wing.
</t>
<t>
Grouped all the rtcp-fb attribute analysis under a single section
as suggested by Magnus/
</t>
</list>
</t>
<t>Changes from draft-nandakumar-mmusic-mux-attributes-03
<list style="symbols">
<t> Maintenance change to clean up grammatical nits and wordings.
</t>
</list>
</t>
<t>Changes from draft-nandakumar-mmusic-mux-attributes-02
<list style="symbols">
<t>Updated Sections 5.3,5.5,5.6,5.7,5.9,5.8,5.11,5.13,5.22,5.34,
5.37,5.40,5.41,5.42,5.43,5.44,5.45,6.1,6.2,6.3,8,3,12.1 based on the
inputs from the respective RFC Authors.
</t>
</list>
</t>
<t>Changes from draft-nandakumar-mmusic-mux-attributes-01
<list style="symbols">
<t>Replaced Category BAD with NOT RECOMMENDED.</t>
<t>Added Category TBD.</t>
<t>Updated IANA Consideration Section.</t>
</list>
</t>
<t>Changes from draft-nandakumar-mmusic-mux-attributes-00
<list style="symbols">
<t>Added new section for dealing with FEC payload types.</t>
</list>
</t>
</section>
</middle>
<back>
<references title="Normative References">
<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='RFC5109'>
<front>
<title>RTP Payload Format for Generic Forward Error Correction</title>
<author initials='A.' surname='Li' fullname='A. Li'>
<organization /></author>
<date year='2007' month='December' />
<abstract>
<t>This document specifies a payload format for generic Forward Error
Correction (FEC) for media data encapsulated in RTP. It is based on the
exclusive-or (parity) operation. The payload format described in this
document allows end systems to apply protection using various protection
lengths and levels, in addition to using various protection group sizes to
adapt to different media and channel characteristics. It enables complete
recovery of the protected packets or partial recovery of the critical parts
of the payload depending on the packet loss situation. This scheme is
completely compatible with non-FEC-capable hosts, so the receivers in a
multicast group that do not implement FEC can still work by simply ignoring
the protection data. This specification obsoletes RFC 2733 and RFC 3009.
The FEC specified in this document is not backward compatible with RFC
2733 and RFC 3009. [STANDARDS-TRACK]</t></abstract></front>
<seriesInfo name='RFC' value='5109' />
<format type='TXT' octets='100538' target='http://www.rfc-editor.org/rfc/rfc5109.txt' />
</reference>
<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='RFC4585'>
<front>
<title>Extended RTP Profile for Real-time Transport Control Protocol
(RTCP)-Based Feedback (RTP/AVPF)</title>
<author initials='J.' surname='Ott' fullname='J. Ott'>
<organization /></author>
<author initials='S.' surname='Wenger' fullname='S. Wenger'>
<organization /></author>
<author initials='N.' surname='Sato' fullname='N. Sato'>
<organization /></author>
<author initials='C.' surname='Burmeister' fullname='C. Burmeister'>
<organization /></author>
<author initials='J.' surname='Rey' fullname='J. Rey'>
<organization /></author>
<date year='2006' month='July' />
</front>
<seriesInfo name='RFC' value='4585' />
<format type='TXT' octets='117762' target='http://www.rfc-editor.org/rfc/rfc4585.txt' />
</reference>
<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. Rosenberg" 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="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="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>S 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>The Session Description Protocol (SDP) Grouping Framework</title>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<author initials='H.' surname='Schulzrinne' fullname='H. Schulzrinne'>
<organization /></author>
<date year='2010' month='June' />
</front>
<seriesInfo name='RFC' value='5888' />
<format type='TXT' octets='43924' target='http://www.rfc-editor.org/rfc/rfc5888.txt' />
</reference>
<reference anchor='RFC4574'>
<front>
<title>The Session Description Protocol (SDP) Label Attribute</title>
<author initials='O.' surname='Levin' fullname='O. Levin'>
<organization /></author>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<date year='2006' month='August' />
</front>
<seriesInfo name='RFC' value='4574' />
<format type='TXT' octets='13484' target='http://www.rfc-editor.org/rfc/rfc4574.txt' />
</reference>
<reference anchor='RFC5432'>
<front>
<title>Quality of Service (QoS) Mechanism Selection in the
Session Description Protocol (SDP)</title>
<author initials='J.' surname='Polk' fullname='J. Polk'>
<organization /></author>
<author initials='S.' surname='Dhesikan' fullname='S. Dhesikan'>
<organization /></author>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<date year='2009' month='March' />
</front>
<seriesInfo name='RFC' value='5432' />
<format type='TXT' octets='17614' target='http://www.rfc-editor.org/rfc/rfc5432.txt' />
</reference>
<reference anchor='RFC4568'>
<front>
<title>S Description Protocol (SDP) Security Descriptions for Media Streams</title>
<author initials='F.' surname='Andreasen' fullname='F. Andreasen'>
<organization /></author>
<author initials='M.' surname='Baugher' fullname='M. Baugher'>
<organization /></author>
<author initials='D.' surname='Wing' fullname='D. Wing'>
<organization /></author>
<date year='2006' month='July' />
</front>
<seriesInfo name='RFC' value='4568' />
<format type='TXT' octets='107881' target='http://www.rfc-editor.org/rfc/rfc4568.txt' />
</reference>
<reference anchor='RFC5762'>
<front>
<title>RTP and the Datagram Congestion Control Protocol (DCCP)</title>
<author initials='C.' surname='Perkins' fullname='C. Perkins'>
<organization /></author>
<date year='2010' month='April' />
</front>
<seriesInfo name='RFC' value='5762' />
<format type='TXT' octets='37537' target='http://www.rfc-editor.org/rfc/rfc5762.txt' />
</reference>
<reference anchor='RFC6773'>
<front>
<title>DCCP-UDP: A Datagram Congestion Control Protocol UDP
Encapsulation for NAT Traversal</title>
<author initials='T.' surname='Phelan' fullname='T. Phelan'>
<organization /></author>
<author initials='G.' surname='Fairhurst' fullname='G. Fairhurst'>
<organization /></author>
<author initials='C.' surname='Perkins' fullname='C. Perkins'>
<organization /></author>
<date year='2012' month='November' />
</front>
<seriesInfo name='RFC' value='6773' />
<format type='TXT' octets='45073' target='http://www.rfc-editor.org/rfc/rfc6773.txt' />
</reference>
<reference anchor='RFC6787'>
<front>
<title>Media Resource Control Protocol Version 2 (MRCPv2)</title>
<author initials='D.' surname='Burnett' fullname='D. Burnett'>
<organization /></author>
<author initials='S.' surname='Shanmugham' fullname='S. Shanmugham'>
<organization /></author>
<date year='2012' month='November' />
</front>
<seriesInfo name='RFC' value='6787' />
<format type='TXT' octets='496648' target='http://www.rfc-editor.org/rfc/rfc6787.txt' />
</reference>
<reference anchor='RFC3890'>
<front>
<title>A Transport Independent Bandwidth Modifier for the
Session Description Protocol (SDP)</title>
<author initials='M.' surname='Westerlund' fullname='M. Westerlund'>
<organization /></author>
<date year='2004' month='September' />
</front>
<seriesInfo name='RFC' value='3890' />
<format type='TXT' octets='49894' target='http://www.rfc-editor.org/rfc/rfc3890.txt' />
</reference>
<reference anchor='RFC3605'>
<front>
<title>Real Time Control Protocol (RTCP) attribute in
Session Description Protocol (SDP)</title>
<author initials='C.' surname='Huitema' fullname='C. Huitema'>
<organization /></author>
<date year='2003' month='October' />
</front>
<seriesInfo name='RFC' value='3605' />
<format type='TXT' octets='17270' target='http://www.rfc-editor.org/rfc/rfc3605.txt' />
</reference>
<reference anchor='RFC5285'>
<front>
<title>A General Mechanism for RTP Header Extensions</title>
<author initials='D.' surname='Singer' fullname='D. Singer'>
<organization /></author>
<author initials='H.' surname='Desineni' fullname='H. Desineni'>
<organization /></author>
<date year='2008' month='July' />
</front>
<seriesInfo name='RFC' value='5285' />
<format type='TXT' octets='36844' target='http://www.rfc-editor.org/rfc/rfc5285.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' />
</front>
<seriesInfo name='RFC' value='5576' />
<format type='TXT' octets='40454' target='http://www.rfc-editor.org/rfc/rfc5576.txt' />
</reference>
<reference anchor='RFC6236'>
<front>
<title>Negotiation of Generic Image Attributes in the
Session Description Protocol (SDP)</title>
<author initials='I.' surname='Johansson' fullname='I. Johansson'>
<organization /></author>
<author initials='K.' surname='Jung' fullname='K. Jung'>
<organization /></author>
<date year='2011' month='May' />
</front>
<seriesInfo name='RFC' value='6236' />
<format type='TXT' octets='49356' target='http://www.rfc-editor.org/rfc/rfc6236.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' />
</front>
<seriesInfo name='RFC' value='5583' />
<format type='TXT' octets='40214' target='http://www.rfc-editor.org/rfc/rfc5583.txt' />
</reference>
<reference anchor='RFC6285'>
<front>
<title>Unicast-Based Rapid Acquisition of Multicast RTP Sessions</title>
<author initials='B.' surname='Ver Steeg' fullname='B. Ver Steeg'>
<organization /></author>
<author initials='A.' surname='Begen' fullname='A. Begen'>
<organization /></author>
<author initials='T.' surname='Van Caenegem' fullname='T. Van Caenegem'>
<organization /></author>
<author initials='Z.' surname='Vax' fullname='Z. Vax'>
<organization /></author>
<date year='2011' month='June' />
</front>
<seriesInfo name='RFC' value='6285' />
<format type='TXT' octets='141497' target='http://www.rfc-editor.org/rfc/rfc6285.txt' />
</reference>
<reference anchor='RFC6230'>
<front>
<title>Media Control Channel Framework</title>
<author initials='C.' surname='Boulton' fullname='C. Boulton'>
<organization /></author>
<author initials='T.' surname='Melanchuk' fullname='T. Melanchuk'>
<organization /></author>
<author initials='S.' surname='McGlashan' fullname='S. McGlashan'>
<organization /></author>
<date year='2011' month='May' />
</front>
<seriesInfo name='RFC' value='6230' />
<format type='TXT' octets='112479' target='http://www.rfc-editor.org/rfc/rfc6230.txt' />
</reference>
<reference anchor='RFC6364'>
<front>
<title>S Description Protocol Elements for the Forward Error Correction
(FEC) Framework</title>
<author initials='A.' surname='Begen' fullname='A. Begen'>
<organization /></author>
<date year='2011' month='October' />
</front>
<seriesInfo name='RFC' value='6364' />
<format type='TXT' octets='36160' target='http://www.rfc-editor.org/rfc/rfc6364.txt' />
</reference>
<reference anchor='RFC3407'>
<front>
<title>S Description Protocol (SDP) Simple Capability Declaration</title>
<author initials='F.' surname='Andreasen' fullname='F. Andreasen'>
<organization /></author>
<date year='2002' month='October' />
</front>
<seriesInfo name='RFC' value='3407' />
<format type='TXT' octets='21133' target='http://www.rfc-editor.org/rfc/rfc3407.txt' />
</reference>
<reference anchor='RFC6284'>
<front>
<title>Port Mapping between Unicast and Multicast RTP Sessions</title>
<author initials='A.' surname='Begen' fullname='A. Begen'>
<organization /></author>
<author initials='D.' surname='Wing' fullname='D. Wing'>
<organization /></author>
<author initials='T.' surname='Van Caenegem' fullname='T. Van Caenegem'>
<organization /></author>
<date year='2011' month='June' />
</front>
<seriesInfo name='RFC' value='6284' />
<format type='TXT' octets='73289' target='http://www.rfc-editor.org/rfc/rfc6284.txt' />
</reference>
<reference anchor='RFC6714'>
<front>
<title>Connection Establishment for Media Anchoring (CEMA) for the
Message Session Relay Protocol (MSRP)</title>
<author initials='C.' surname='Holmberg' fullname='C. Holmberg'>
<organization /></author>
<author initials='S.' surname='Blau' fullname='S. Blau'>
<organization /></author>
<author initials='E.' surname='Burger' fullname='E. Burger'>
<organization /></author>
<date year='2012' month='August' />
</front>
<seriesInfo name='RFC' value='6714' />
<format type='TXT' octets='50543' target='http://www.rfc-editor.org/rfc/rfc6714.txt' />
</reference>
<reference anchor='RFC6679'>
<front>
<title>Explicit Congestion Notification (ECN) for RTP over UDP</title>
<author initials='M.' surname='Westerlund' fullname='M. Westerlund'>
<organization /></author>
<author initials='I.' surname='Johansson' fullname='I. Johansson'>
<organization /></author>
<author initials='C.' surname='Perkins' fullname='C. Perkins'>
<organization /></author>
<author initials='P.' surname='O'Hanlon' fullname='P. O'Hanlon'>
<organization /></author>
<author initials='K.' surname='Carlberg' fullname='K. Carlberg'>
<organization /></author>
<date year='2012' month='August' />
</front>
<seriesInfo name='RFC' value='6679' />
<format type='TXT' octets='148560' target='http://www.rfc-editor.org/rfc/rfc6679.txt' />
</reference>
<reference anchor='RFC4583'>
<front>
<title>S Description Protocol (SDP) Format for Binary Floor Control Protocol (BFCP) Streams</title>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<date year='2006' month='November' />
</front>
<seriesInfo name='RFC' value='4583' />
<format type='TXT' octets='24150' target='http://www.rfc-editor.org/rfc/rfc4583.txt' />
</reference>
<reference anchor='RFC5547'>
<front>
<title>A Session Description Protocol (SDP) Offer/Answer Mechanism to
Enable File Transfer</title>
<author initials='M.' surname='Garcia-Martin' fullname='M. Garcia-Martin'>
<organization /></author>
<author initials='M.' surname='Isomaki' fullname='M. Isomaki'>
<organization /></author>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<author initials='S.' surname='Loreto' fullname='S. Loreto'>
<organization /></author>
<author initials='P.' surname='Kyzivat' fullname='P. Kyzivat'>
<organization /></author>
<date year='2009' month='May' />
</front>
<seriesInfo name='RFC' value='5547' />
<format type='TXT' octets='112625' target='http://www.rfc-editor.org/rfc/rfc5547.txt' />
</reference>
<reference anchor='RFC5760'>
<front>
<title>RTP Control Protocol (RTCP) Extensions for Single-Source
Multicast Sessions with Unicast Feedback</title>
<author initials='J.' surname='Ott' fullname='J. Ott'>
<organization /></author>
<author initials='J.' surname='Chesterfield' fullname='J. Chesterfield'>
<organization /></author>
<author initials='E.' surname='Schooler' fullname='E. Schooler'>
<organization /></author>
<date year='2010' month='February' />
</front>
<seriesInfo name='RFC' value='5760' />
<format type='TXT' octets='160368' target='http://www.rfc-editor.org/rfc/rfc5760.txt' />
</reference>
<reference anchor='RFC3611'>
<front>
<title>RTP Control Protocol Extended Reports (RTCP XR)</title>
<author initials='T.' surname='Friedman' fullname='T. Friedman'>
<organization /></author>
<author initials='R.' surname='Caceres' fullname='R. Caceres'>
<organization /></author>
<author initials='A.' surname='Clark' fullname='A. Clark'>
<organization /></author>
<date year='2003' month='November' />
</front>
<seriesInfo name='RFC' value='3611' />
<format type='TXT' octets='126736' target='http://www.rfc-editor.org/rfc/rfc3611.txt' />
</reference>
<reference anchor='RFC5939'>
<front>
<title>S Description Protocol (SDP) Capability Negotiation</title>
<author initials='F.' surname='Andreasen' fullname='F. Andreasen'>
<organization /></author>
<date year='2010' month='September' />
</front>
<seriesInfo name='RFC' value='5939' />
<format type='TXT' octets='188116' target='http://www.rfc-editor.org/rfc/rfc5939.txt' />
</reference>
<reference anchor='RFC4567'>
<front>
<title>Key Management Extensions for Session Description Protocol (SDP)
and Real Time Streaming Protocol (RTSP)</title>
<author initials='J.' surname='Arkko' fullname='J. Arkko'>
<organization /></author>
<author initials='F.' surname='Lindholm' fullname='F. Lindholm'>
<organization /></author>
<author initials='M.' surname='Naslund' fullname='M. Naslund'>
<organization /></author>
<author initials='K.' surname='Norrman' fullname='K. Norrman'>
<organization /></author>
<author initials='E.' surname='Carrara' fullname='E. Carrara'>
<organization /></author>
<date year='2006' month='July' />
</front>
<seriesInfo name='RFC' value='4567' />
<format type='TXT' octets='67693' target='http://www.rfc-editor.org/rfc/rfc4567.txt' />
</reference>
<reference anchor='RFC4572'>
<front>
<title>Connection-Oriented Media Transport over the
Transport Layer Security (TLS) Protocol in the
Session Description Protocol (SDP)</title>
<author initials='J.' surname='Lennox' fullname='J. Lennox'>
<organization /></author>
<date year='2006' month='July' />
</front>
<seriesInfo name='RFC' value='4572' />
<format type='TXT' octets='38658' target='http://www.rfc-editor.org/rfc/rfc4572.txt' />
</reference>
<reference anchor='RFC4570'>
<front>
<title>S Description Protocol (SDP) Source Filters</title>
<author initials='B.' surname='Quinn' fullname='B. Quinn'>
<organization /></author>
<author initials='R.' surname='Finlayson' fullname='R. Finlayson'>
<organization /></author>
<date year='2006' month='July' />
</front>
<seriesInfo name='RFC' value='4570' />
<format type='TXT' octets='28601' target='http://www.rfc-editor.org/rfc/rfc4570.txt' />
</reference>
<reference anchor='RFC6128'>
<front>
<title>RTP Control Protocol (RTCP) Port for
Source-Specific Multicast (SSM) Sessions</title>
<author initials='A.' surname='Begen' fullname='A. Begen'>
<organization /></author>
<date year='2011' month='February' />
</front>
<seriesInfo name='RFC' value='6128' />
<format type='TXT' octets='11544' target='http://www.rfc-editor.org/rfc/rfc6128.txt' />
</reference>
<reference anchor='RFC6189'>
<front>
<title>ZRTP: Media Path Key Agreement for Unicast Secure RTP</title>
<author initials='P.' surname='Zimmermann' fullname='P. Zimmermann'>
<organization /></author>
<author initials='A.' surname='Johnston' fullname='A. Johnston'>
<organization /></author>
<author initials='J.' surname='Callas' fullname='J. Callas'>
<organization /></author>
<date year='2011' month='April' />
</front>
<seriesInfo name='RFC' value='6189' />
<format type='TXT' octets='293784' target='http://www.rfc-editor.org/rfc/rfc6189.txt' />
</reference>
<reference anchor='RFC4145'>
<front>
<title>TCP-Based Media Transport in the Session Description Protocol (SDP)</title>
<author initials='D.' surname='Yon' fullname='D. Yon'>
<organization /></author>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<date year='2005' month='September' />
</front>
<seriesInfo name='RFC' value='4145' />
<format type='TXT' octets='30225' target='http://www.rfc-editor.org/rfc/rfc4145.txt' />
</reference>
<reference anchor='RFC6193'>
<front>
<title>Media Description for the Internet Key Exchange Protocol (IKE)
in the Session Description Protocol (SDP)</title>
<author initials='M.' surname='Saito' fullname='M. Saito'>
<organization /></author>
<author initials='D.' surname='Wing' fullname='D. Wing'>
<organization /></author>
<author initials='M.' surname='Toyama' fullname='M. Toyama'>
<organization /></author>
<date year='2011' month='April' />
</front>
<seriesInfo name='RFC' value='6193' />
<format type='TXT' octets='50201' target='http://www.rfc-editor.org/rfc/rfc6193.txt' />
</reference>
<reference anchor='RFC6642'>
<front>
<title>RTP Control Protocol (RTCP) Extension for a Third-Party Loss Report</title>
<author initials='Q.' surname='Wu' fullname='Q. Wu'>
<organization /></author>
<author initials='F.' surname='Xia' fullname='F. Xia'>
<organization /></author>
<author initials='R.' surname='Even' fullname='R. Even'>
<organization /></author>
<date year='2012' month='June' />
</front>
<seriesInfo name='RFC' value='6642' />
<format type='TXT' octets='29758' target='http://www.rfc-editor.org/rfc/rfc6642.txt' />
</reference>
<reference anchor='RFC6064'>
<front>
<title>SDP and RTSP Extensions Defined for 3GPP Packet-Switched
Streaming Service and Multimedia Broadcast/Multicast Service</title>
<author initials='M.' surname='Westerlund' fullname='M. Westerlund'>
<organization /></author>
<author initials='P.' surname='Frojdh' fullname='P. Frojdh'>
<organization /></author>
<date year='2011' month='January' />
</front>
<seriesInfo name='RFC' value='6064' />
<format type='TXT' octets='44810' target='http://www.rfc-editor.org/rfc/rfc6064.txt' />
</reference>
<reference anchor='RFC4091'>
<front>
<title>The Alternative Network Address Types (ANAT) Semantics for the
Session Description Protocol (SDP) Grouping Framework</title>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<author initials='J.' surname='Rosenberg' fullname='J. Rosenberg'>
<organization /></author>
<date year='2005' month='June' />
</front>
<seriesInfo name='RFC' value='4091' />
<format type='TXT' octets='12931' target='http://www.rfc-editor.org/rfc/rfc4091.txt' />
</reference>
<reference anchor='RFC5956'>
<front>
<title>Forward Error Correction Grouping Semantics in the
Session Description Protocol</title>
<author initials='A.' surname='Begen' fullname='A. Begen'>
<organization /></author>
<date year='2010' month='September' />
</front>
<seriesInfo name='RFC' value='5956' />
<format type='TXT' octets='29530' target='http://www.rfc-editor.org/rfc/rfc5956.txt' />
</reference>
<reference anchor='RFC3108'>
<front>
<title>Conventions for the use of the Session Description Protocol
(SDP) for ATM Bearer Connections</title>
<author initials='R.' surname='Kumar' fullname='R. Kumar'>
<organization /></author>
<author initials='M.' surname='Mostafa' fullname='M. Mostafa'>
<organization /></author>
<date year='2001' month='May' />
</front>
<seriesInfo name='RFC' value='3108' />
<format type='TXT' octets='248037' target='http://www.rfc-editor.org/rfc/rfc3108.txt' />
</reference>
<reference anchor='RFC5159'>
<front>
<title>S Description Protocol (SDP) Attributes for Open Mobile Alliance (OMA) Broadcast (BCAST) Service and Content Protection</title>
<author initials='L.' surname='Dondeti' fullname='L. Dondeti'>
<organization /></author>
<author initials='A.' surname='Jerichow' fullname='A. Jerichow'>
<organization /></author>
<date year='2008' month='March' />
</front>
<seriesInfo name='RFC' value='5159' />
<format type='TXT' octets='13921' target='http://www.rfc-editor.org/rfc/rfc5159.txt' />
</reference>
<reference anchor='RFC3524'>
<front>
<title>Mapping of Media Streams to Resource Reservation Flows</title>
<author initials='G.' surname='Camarillo' fullname='G. Camarillo'>
<organization /></author>
<author initials='A.' surname='Monrad' fullname='A. Monrad'>
<organization /></author>
<date year='2003' month='April' />
</front>
<seriesInfo name='RFC' value='3524' />
<format type='TXT' octets='11249' target='http://www.rfc-editor.org/rfc/rfc3524.txt' />
</reference>
<reference anchor='RFC5763'>
<front>
<title>Framework for Establishing a Secure Real-time Transport Protocol
(SRTP) Security Context Using Datagram Transport Layer Security (DTLS)</title>
<author initials='J.' surname='Fischl' fullname='J. Fischl'>
<organization /></author>
<author initials='H.' surname='Tschofenig' fullname='H. Tschofenig'>
<organization /></author>
<author initials='E.' surname='Rescorla' fullname='E. Rescorla'>
<organization /></author>
<date year='2010' month='May' />
</front>
<seriesInfo name='RFC' value='5763' />
<format type='TXT' octets='81546' target='http://www.rfc-editor.org/rfc/rfc5763.txt' />
</reference>
<reference anchor='RFC4975'>
<front>
<title>The Message Session Relay Protocol (MSRP)</title>
<author initials='B.' surname='Campbell' fullname='B. Campbell'>
<organization /></author>
<author initials='R.' surname='Mahy' fullname='R. Mahy'>
<organization /></author>
<author initials='C.' surname='Jennings' fullname='C. Jennings'>
<organization /></author>
<date year='2007' month='September' />
</front>
<seriesInfo name='RFC' value='4975' />
<format type='TXT' octets='144254' target='http://www.rfc-editor.org/rfc/rfc4975.txt' />
</reference>
<reference anchor='MEDIA_LOOPBACK'>
<front>
<title>An Extension to the Session Description Protocol (SDP)
and Real-time Transport Protocol (RTP) for Media Loopback
</title>
<author initials='H.' surname='Kaplan' fullname='H. Kaplan'>
<organization /></author>
<author initials='K.' surname='Hedayat' fullname='K. Hedayat'>
<organization /></author>
<author initials='N.' surname='Venna' fullname='N. Venna'>
<organization /></author>
<author initials='P.' surname='Jones' fullname='P. Jones'>
<organization /></author>
<author initials='N.' surname='Stratton' fullname='N. Stratton'>
<organization /></author>
<date year='2013' month='January' />
</front>
<seriesInfo name='Internet-Draft' value='6489' />
<format type='TXT' target='http://tools.ietf.org/rfc/rfc6849.txt' />
</reference>
<reference anchor="I-D.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 Alvestrand" initials="H" surname="Alvestrand">
<organization></organization>
</author>
<author fullname="Cullen Jennings" initials="C" surname="Jennings">
<organization></organization>
</author>
<date day="18" month="February" year="2013" />
<abstract>
<t>This specification defines a new SDP Grouping Framework extension,
"BUNDLE", that can be used with the Session Description Protocol
(SDP) Offer/Answer mechanism to negotiate the usage of bundled media,
which refers to the usage of a single 5-tuple for media associated
with multiple SDP media descriptions ("m=" lines).</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft"
value="draft-ietf-mmusic-sdp-bundle-negotiation-03" />
<format target="http://tools.ietf.org/html/draft-holmberg-mmusic-sdp-bundle-negotiation-03.txt"
type="TXT" />
</reference>
<reference anchor="I-D.ietf-avt-multiplexing-rtp">
<front>
<title>Multiplexing Scheme for RTP Flows between Access Routers</title>
<author fullname="Khalil M. El-Khatib" initials="K" surname="El-Khatib">
<organization></organization>
</author>
<author fullname="Gang Luo" initials="G" surname="Luo">
<organization></organization>
</author>
<author fullname="Gregor v. Bochmann" initials="G" surname="Bochmann">
<organization></organization>
</author>
<author fullname="Pinjiang Feng" initials="Pinjiang" surname="Feng">
<organization></organization>
</author>
<date day="22" month="October" year="1999" />
<abstract>
<t>This draft proposes a light-weight data driven approach for
multiplexing low bit rate RTP streams at the edge router of the
Internet in order to reduce the RTP/UDP/IP header overhead associated
with each RTP stream. Audio packets from different sources in a local
access network destined to different users in the same remote access
network are multiplexed into one packet, with the original RTP/UDP/IP
header of each packet replaced with a mini-header (2 bytes), resulting
in a reduction of the overhead. Access routers can use the IP telephony
Border Gateway Protocol (TBGP) to exchange the reachability of IP
destinations in their domains.</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft"
value="http://tools.ietf.org/html/draft-ietf-avt-multiplexing-rtp-01" />
<format target="http://tools.ietf.org/html/draft-ietf-avt-multiplexing-rtp-01.txt"
type="TXT" />
</reference>
<reference anchor='RFC6871'>
<front>
<title>Session Description Protocol (SDP) Media Capabilities Negotiation</title>
<author initials='R.' surname='Gimlan' fullname='Robert RGilman'>
<organization /></author>
<author initials='R.' surname='Evan' fullname=' R. Even'>
<organization /></author>
<author initials='F.' surname='Andreasen' fullname='Flemming Andreasen'>
<organization /></author>
<date year='2013' month='Febrauary' />
</front>
<seriesInfo name='RFC' value='6871' />
<format type='TXT' target='https://tools.ietf.org/html/rfc6871.txt' />
</reference>
<reference anchor='IANA' target="http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xml">
<front>
<title>S Description Protocol (SDP) Parameters</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='T.38' target="http://www.itu.int/rec/T-REC-T.38/e">
<front>
<title>Procedures for real-time Group 3 facsimile communication over IP networks</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='H.248.15' target="http://www.itu.int/rec/T-REC-H.248.15">
<front>
<title> Gateway control protocol: SDP H.248 package attribute</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='R3GPPTS24.229' target="http://www.3gpp.org/ftp/Specs/html-info/24229.htm">
<front>
<title>IP multimedia call control protocol based on
Session Initiation Protocol (SIP)
and Session Description Protocol (SDP);</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='R3GPPTS24.182' target="http://www.3gpp.org/ftp/Specs/html-info/24182.htm">
<front>
<title>IP Multimedia Subsystem (IMS) Customized Alerting Tones (CAT);
Protocol specification</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='R3GPPTS24.183' target="http://www.3gpp.org/ftp/Specs/html-info/24183.htm">
<front>
<title>IP Multimedia Subsystem (IMS) Customized Ringing Signal (CRS);
Protocol specification</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='RTCP-FB'
target="http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xml#sdp-parameters-14">
<front>
<title>S Description Protocol (SDP) RTCP Feedback attributes</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='ACK-NACK'
target="http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xml#sdp-parameters-15">
<front>
<title>S Description Protocol (SDP) RTCP ACK/NACK Feedback attributes</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='CCM'
target="http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xml#sdp-parameters-19">
<front>
<title>S Description Protocol (SDP) RTCP-FB Codec Control Messages</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='GROUP-SEM'
target="http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xml#sdp-parameters-13">
<front>
<title>S Description Protocol (SDP) "group" semantics</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='SSRC-GROUP'
target="http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xml#sdp-parameters-17">
<front>
<title>S Description Protocol (SDP) "ssrc-group" semantics</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='QOS'
target="http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xml#sdp-parameters-20">
<front>
<title>S Description Protocol (SDP) QoS Mechanism Tokens</title>
<author/>
<date/>
</front>
</reference>
<reference anchor='I-D.dhesikan-tsvwg-rtcweb-qos'>
<front>
<title>DSCP and other packet markings for RTCWeb QoS</title>
<author initials='S' surname='Dhesikan' fullname='Subha Dhesikan'>
<organization />
</author>
<author initials='D' surname='Druta' fullname='Dan Druta'>
<organization />
</author>
<author initials='P' surname='Jones' fullname='Paul Jones'>
<organization />
</author>
<author initials='J' surname='Polk' fullname='James Polk'>
<organization />
</author>
<date month='July' day='15' year='2013' />
<abstract><t>Many networks, such as service provider and enterprise networks, can provide per packet treatments based on Differentiated Services Code Points (DSCP) on a per hop basis. This document provides the recommended DSCP values for browsers to use for various classes of traffic.</t></abstract>
</front>
<seriesInfo name='Internet-Draft' value='draft-dhesikan-tsvwg-rtcweb-qos-02' />
<format type='TXT'
target='http://www.ietf.org/internet-drafts/draft-dhesikan-tsvwg-rtcweb-qos-02.txt' />
</reference>
</references>
</back>
</rfc>
| PAFTECH AB 2003-2026 | 2026-04-23 09:32:06 |