One document matched: draft-westerlund-mmusic-3gpp-sdp-rtsp-07.xml
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<rfc category="info" docName="draft-westerlund-mmusic-3gpp-sdp-rtsp-07"
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<front>
<title abbrev="SDP & RTSP extensions for 3GPP">SDP and RTSP extensions
defined for 3GPP Packet-switched Streaming Service and Multimedia
Broadcast/Multicast Service</title>
<author fullname="Magnus Westerlund" initials="M." surname="Westerlund">
<organization>Ericsson</organization>
<address>
<postal>
<street>Farogatan 6</street>
<city>Stockholm</city>
<code>SE-164 80</code>
<region></region>
<country>SWEDEN</country>
</postal>
<phone>+46 8 7190000</phone>
<facsimile>+46 8 757 55 50</facsimile>
<email>magnus.westerlund@ericsson.com</email>
</address>
</author>
<author fullname="Per Frojdh" initials="P." surname="Frojdh">
<organization>Ericsson</organization>
<address>
<postal>
<street>Farogatan 6</street>
<city>Stockholm</city>
<code>SE-164 80</code>
<region></region>
<country>SWEDEN</country>
</postal>
<phone>+46 8 7190000</phone>
<facsimile>+46 8 757 55 50</facsimile>
<email>per.frojdh@ericsson.com</email>
</address>
</author>
<date day="08" month="May" year="2009" />
<abstract>
<t>The Packet-switched Streaming Service (PSS) and the Multimedia
Broadcast/Multicast Service (MBMS) defined by 3GPP use SDP and RTSP with
some extensions. This document provides information about these
extensions and registers the RTSP and SDP extensions with IANA.</t>
</abstract>
<note title="Requirements Language">
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in <xref
target="RFC2119">RFC 2119</xref>.</t>
</note>
</front>
<middle>
<section title="Definitions">
<t></t>
<section title="Glossary">
<t><list style="hanging">
<t hangText="3GP:">3GPP file format, a multi-media file format
based on the ISO base media file format, existing in different
profiles intended for multimedia messages, direct playback on
clients, progressive download, usage on servers to deliver
on-demand multi-media sessions in PSS, or servers sending MBMS
sessions.</t>
<t hangText="3GPP:">Third Generation Partnership Project, see
www.3gpp.org for more information about this organization.</t>
<t hangText="FEC:">Forward Error Correction</t>
<t hangText="MBMS:">Multimedia Broadcast/Multicast Service, a
service defined by 3GPP that utilizes broadcast or multicast
technologhy in combination with unicast for delivery of a wide
range of content to mobile terminals.</t>
<t hangText="PSS:">Packet-switched Streaming Service, a
unicast-based streaming service for delivery of on-demand or live
streaming multi-media content to mobile terminals.</t>
<t hangText="RTSP:">Time Streaming Protocol, see <xref
target="RFC2326"></xref>.</t>
<t hangText="SDP:">Session Description Protocol, see <xref
target="RFC4566"></xref>.</t>
<t hangText="SRTP:">Secure Real-time Transport Protocol, see <xref
target="RFC3711"></xref>.</t>
<t hangText="QoE:">Quality of Experience, the quality level of the
the user experience of a service. In PSS this is estimated by a
combination of application-level metrics.</t>
<t hangText="QoS:">Quality of Service, the quality (properties)
that the network provides toward the upper layer service.</t>
</list></t>
<t></t>
</section>
</section>
<section title="Introduction">
<t>3GPP has specified the Packet-switched Streaming Service (PSS) that
uses both <xref target="RFC2326">RTSP</xref> and <xref
target="RFC4566">SDP</xref>. The service is specified in technical
specifications <xref target="PSS-233">TS 26.233</xref> and <xref
target="PSS-234">TS 26.234</xref> in Release 4 and later releases. The
basic service defined in Release 4 is enhanced in Release 5 with
capability exchange and in Release 6 with a number of features, such as
adaptation, digital rights management, progressive download as well as a
streaming server file-format defined in <xref target="PSS-3GP"></xref>.
Fast start-up and content switching are addressed in Release 7.</t>
<t>3GPP has also specified the Multimedia Broadcast/Multicast Service
(MBMS) that uses SDP. The IP layer protocols used by this service are
specified in technical specification TS 26.346 Release 6 <xref
target="MBMS"></xref>. Release 7 extends the MBMS User Service to also
work with unicast bearers for interactive and streaming traffic
classes.</t>
<t>In the process of defining these services, there has occasionally
been the need to extend both SDP and RTSP functionality. These
extensions have mostly been in the form of SDP attributes and RTSP
headers and option tags. 3GPP uses the name option tags (like RTSP 2.0
for what RTSP 1.0 calls option tags, option tag is the name that will be
used in this document. The purpose of this informational document is to
register these SDP and RTSP extensions, in order to avoid future
conflicts, and also to raise the awareness of their existence within
IETF.</t>
<t>This document defines in <xref target="sec-sdp-proto"></xref> three
SDP protocol identifiers used in MBMS to enable the usage of block-based
FEC. The other SDP and RTSP extensions registered by this document are
not normatively defined in this document. Instead the normative
definitions are referenced by the registrations.</t>
<t>The document begins with two chapters presenting the different
extensions of SDP for PSS and MBMS, respectively, followed by a section
noting that offer/answer considerations are not applicable here. The
subsequent section presents the extensions of RTSP for PSS. The IANA
registration of SDP attributes and protocol identifiers is given in
<xref target="sec-iana-sdp"></xref>, and the RTSP headers and option
tags in <xref target="sec-iana-rtsp"></xref>. For normative descriptions
of all SDP and RTSP extensions we refer to <xref target="PSS-234">TS
26.234</xref> and <xref target="MBMS">TS 26.346</xref>.</t>
</section>
<section title="Applicability Statement">
<t>This document describes 3GPP-defined extensions to <xref
target="RFC4566">SDP</xref> and <xref target="RFC2326">RTSP</xref> and
registers attributes that are normatively defined in 3GPP technical
specifications 26.234, 26.244 and 26.346 up to the referenced versions
of the respective documents.</t>
<t>The SDP and RTSP extensions have only been defined for usage with the
3GPP service in mind. The applicability for usage outside of these
services has not been considered or addressed. Usage of these attributes
in other contexts may require further definitions or clarifications. For
example, all SDP attributes lack offer/answer usage rules <xref
target="RFC3264"></xref> which currently makes it impossible to use them
with offer/answer. Please note that change control of these SDP and RTSP
extensions belongs to 3GPP.</t>
</section>
<section title="PSS SDP Extensions">
<t>The PSS specification <xref target="PSS-234"></xref> defines a number
of different SDP attributes for different purposes. They are
informatively listed below grouped by purpose. The text is intentionally
not specific enough to allow implementation from this document. The
normative definition is in the 3GPP technical specification cited.</t>
<section title="Video Buffering Attributes">
<t>The following attributes are used to provide parameters for the
video buffer model provided in Annex G and Section 5.3.3.2 of <xref
target="PSS-234"></xref>. The attributes were defined in Release 5 as
"X-" attributes and were at the time not considered for registration.
In hindsight, however, they should not have been "X-" attributes, and
they should have been registered, as the registration rules of SDP
<xref target="RFC4566"></xref> point out. Changing their names today
is impossible due to the deployed base of millions of mobile handsets
supporting PSS, and therefore they are registered in their current
form.</t>
<t>All attributes are defined at media level.</t>
<t><list style="symbols">
<t>The "a=X-predecbufsize" attribute provides the size of the
pre-decoder buffer in bytes.</t>
<t>The "a=X-initpredecbufperiod" attribute provides the time
during which a receiver should initially buffer, in 90kHz ticks,
before starting to consume the data in the buffer in order to
ensure that underflow does not occur, assuming correct data
delivery.</t>
<t>The "a=X-initpostdecbufperiod" attribute provides the initial
buffering period, in 90kHz ticks, for the post-decoder buffer
present in H.263 and MPEG-4 Visual.</t>
<t>The "a=X-decbyterate" attribute indicates the maximum peak
byte-decoding rate used in the verification of the Annex G buffer
model expressed in bytes per second.</t>
<t>The "a=3gpp-videopostdecbufsize" attribute is used to indicate
the value used in determining the H.264 video post-decoder buffer
size.</t>
</list>Note that complete descriptions of these attributes can be
found in section 5.3.3.2 of <xref target="PSS-234"></xref>.</t>
</section>
<section title="Video Frame Size Attribute">
<t>This media-level attribute provides the receiver with the largest
picture size a specific H.263 payload type will carry within the
session. The attribute has the following form (see 5.3.3.2 of <xref
target="PSS-234"></xref>):</t>
<t>"a=framesize:<payload type number>
<width>-<height>"</t>
</section>
<section title="Integrity Protection Configuration Attributes">
<t>These attributes are all used to configure the integrity-protection
mechanism defined in Annex K (section K.2.2.1, K.2.2.2 and K.2.2.3) of
<xref target="PSS-234"></xref>.</t>
<t><list style="symbols">
<t>The session-level attribute "a=3GPP-Integrity-Key" carries the
integrity key used to derive SRTP master keys for integrity
protection. They key is protected in different ways depending on a
method identifier. When using OMA DRM keymanagement, the key is
encrypted using AES [AES] before it is base64 encoded <xref
target="RFC4648"></xref>.</t>
<t>The media-level attribute "a=3GPP-SRTP-Config" is used to
configure SRTP for integrity protection and contains an integrity
nonce, a key salt used in deriving the SRTP master key from the
integrity key, and any SRTP configuration parameters, such as the
integrity tag length.</t>
<t>The session-level attribute "a=3GPP-SDP-Auth" is used to carry
an authentication tag calculated over certain parts of the SDP to
prevent manipulation of the security attributes.</t>
</list></t>
</section>
<section title="The Alternative Attributes">
<t>Two media and one session-level attributes are used in a mechanism
for providing alternative SDP lines. One or more SDP lines at media
level can be replaced, if desired, by alternatives. The mechanism is
backwards compatible in the way that a receiver that does not support
the attributes will get the default configuration. The different
alternatives can be grouped using different attributes that can be
specified hierarchically with a top and a lower level. 3GPP Release 6
supports grouping based on bit-rate, according to the SDP bandwidth
modifiers AS and TIAS, and language.</t>
<t>The SDP attributes (see 5.3.3.3 and 5.3.3.4 of <xref
target="PSS-234"></xref>) are: <list style="symbols">
<t>The media-level attribute "a=alt:<id>:<SDP-Line>"
carries any SDP line and an alternative identifier.</t>
<t>The media-level attribute "a=alt-default-id:<id>"
identifies the default configuration to be used in groupings.</t>
<t>The session-level attribute "a=alt-group" is used to group
different recommended media alternatives. Providing aggregated
properties for the whole group according to the grouping type.
Language and bit-rate are two defined grouping types.</t>
</list></t>
</section>
<section title="Adaptation Attribute">
<t>The media-level SDP attribute "a=3GPP-Adaptation-Support" (see
5.3.3.5 of <xref target="PSS-234"></xref>) is defined as part of the
negotiation procedure of the PSS adaptation mechanism. The attribute
carries a single value indicating how often the RTCP "Next Application
Data Unit" (NADU) APP packet shall be included in sent RTCP compound
packets. The adaptation mechanism allows the client to provide the
server with information on the available transmission bit-rate and
receiver buffer status.</t>
</section>
<section title="Quality of Experience Attribute">
<t>The session and media-level attribute "a=3GPP-QoE-Metrics" (see
5.3.3.6 of <xref target="PSS-234"></xref>]) is used to negotiate the
usage of the quality of experience metrics. The included parameters
indicate which metrics, over which duration there should be
measurements, and how often reports should be sent.</t>
</section>
<section title="Asset Information Attribute">
<t>The session and media-level attribute "a=3GPP-Asset-Information"
(see 5.3.3.7 of <xref target="PSS-234"></xref>) can exist in multiple
instances in a description and describes different types of asset
information. The different asset classes defined in Release 6 are:
Title, Description, Copyright, Performer, Author, Genre, Rating,
Classification, Keywords, Location, Album, and Recording Year. The
different assets are described with a BASE64-encoded asset box from
the 3GP file format <xref target="PSS-3GP"></xref>.</t>
</section>
</section>
<section title="MBMS SDP Extensions">
<t>The MBMS specification [MBMS] defines a number of different SDP
attributes for different purposes. They are informatively listed
below.</t>
<section title="MBMS Bearer Mode Declaration Attribute">
<t>The session and media-level attribute "a=mbms-mode" (see 7.3.2.7 of
<xref target="MBMS"></xref>) is used to describe MBMS broadcast mode
media. The attribute may be used at session level to set the default
for all media and at media level to specify differences between media.
However, the attribute is never used at session level when the session
includes MBMS multicast mode media, nor at media level to describe
MBMS multicast mode media.</t>
</section>
<section title="FEC Flow ID Attribute">
<t>The media-level attribute "a=mbms-flowid" (see 8.3.1.9 of <xref
target="MBMS"></xref>) maps one or more FEC source block flow IDs to
their corresponding destination IP addresses and UDP port numbers. It
is present in each SDP media block for repair packet streams.</t>
</section>
<section title="MBMS Repair Attribute">
<t>The session and media-level attribute "a=mbms-repair" (see 8.3.1.8
of <xref target="MBMS"></xref>) is used to provide FEC repair packets
with non-FEC specific parameters. For Release 6 one such parameter is
defined, specifying the required minimum receiver buffer time.</t>
</section>
<section anchor="sec-sdp-proto" title="SDP Protocol Identifiers for FEC">
<t>MBMS defines a mechanism to provide block-based FEC for UDP-based
traffic. This solution uses the SDP protocol "proto" identifier to
identify the media streams that use the FEC shim layer. The media
streams may be either source streams and repair streams. As required
by <xref target="RFC4566">SDP</xref> these protocol identifiers are
normatively defined in this document in accordance with their usage
specified by 3GPP.</t>
<section title="RTP Protocol Identifiers">
<t>For FEC-protected RTP streams the following two "proto"
identifiers are defined: <list style="symbols">
<t>UDP/MBMS-FEC/RTP/AVP</t>
<t>UDP/MBMS-FEC/RTP/SAVP</t>
</list>They indicate the usage of <xref
target="RFC0768">UDP</xref> with MBMS FEC Source packet formats, as
defined in Section 8.2.2.4 of <xref target="MBMS"></xref>, that
transport RTP packets in accordance with the <xref
target="RFC3551">AVP</xref> or SAVP (Secure RTP) <xref
target="RFC3711"></xref> profiles, respectively. These protocol
identifiers SHALL use the FMT space rules that are used for RTP/AVP
and RTP/SAVP, respectively.</t>
</section>
<section title="FEC Repair Data Identifier">
<t>A media stream carrying MBMS FEC repair information over UDP
requires its own "proto" identifier. Protocol identifier
"UDP/MBMS-REPAIR" identifies the FEC repair packet containing the
protocol combination of <xref target="RFC0768">UDP</xref> and FEC
repair payload ID and repair symbols as specified in Section 8.2.2.5
of <xref target="MBMS"></xref>. The FMT string is not used and SHALL
be set to "*".</t>
</section>
</section>
<section title="Video Buffering Attribute">
<t>The PSS media-level buffer attribute "a=X-initpredecbufperiod"(See
Section 4.1) that specifies an initial buffering time is also used for
MBMS in Release 7. It is mainly intended for video streams, but may be
used for other media types as well (See Section 8.3.1.1 of <xref
target="MBMS"></xref>).</t>
</section>
</section>
<section title="SDP Offer/Answer Consideration">
<t>The usage of the SDP attributes in an Offer/Answer <xref
target="RFC3264"></xref> context is not defined. These SDP attributes
are defined for being used in a declarative context, and for PSS
specifically in RTSP <xref target="RFC2326"></xref> context.</t>
</section>
<section title="PSS RTSP Extensions">
<t>The RTSP extensions for PSS consist of a number of new RTSP headers
and option tags and a narrowing of URI usage in regards to 3GP files.
The headers and option tags are informatively described here; see
[PSS-234] for the normative declaration.</t>
<section title="3GPP-Link-Char Header">
<t>The "3GPP-Link-Char" header (see 5.3.2.1 of <xref
target="PSS-234"></xref>) is used by clients to provide the server
with QoS information about the wireless link it is currently using.
The header can be used to provide the server with three different QoS
parameters:<list style="symbols">
<t>Guaranteed Bandwidth</t>
<t>Maximum Bandwidth</t>
<t>Maximum Transfer Delay</t>
</list>The header may be included in RTSP requests using either of
the methods SETUP, PLAY, OPTIONS and SET_PARAMETER.</t>
</section>
<section title="3GPP-Adaptation Header">
<t>The "3GPP-Adaptation" header (see 5.3.2.2 of <xref
target="PSS-234"></xref>) is used by the client to provide the server
with adaptation-related parameters and to indicate support of the
adaptation function. The header carries the resource identification as
a URI, the client's buffer size, and the desired target time.</t>
<t>The header may be included in requests using the methods SETUP,
PLAY, OPTIONS and SET_PARAMETER. The response to a request using this
method shall include this header.</t>
</section>
<section title="3GPP-QoE-Metrics Header">
<t>The "3GPP-QoE-Metrics" header (see 5.3.2.3.1 of <xref
target="PSS-234"></xref>) is used to negotiate the usage of the
quality of experience (QoE) metrics (see Section 11 of <xref
target="PSS-234"></xref>).</t>
<t>The header may be included in requests and responses using the
SETUP, SET_PARAMTER, OPTIONS or PLAY method.</t>
</section>
<section title="3GPP-QoE-Feedback Header">
<t>The "3GPP-QoE-Feedback" header (see 5.3.2.3.2 of <xref
target="PSS-234"></xref>) is used to carry QoE metrics from the client
to the server when it reports, which happen either during or at the
end of the media delivery.</t>
<t>The header may be included in requests using the SET_PARAMETER,
PAUSE, or TEARDOWN method.</t>
</section>
<section title="Video Buffer Headers">
<t>PSS uses several headers to provide the client with the different
buffer parameters. They provide the buffer status at the point of a
stream that a PLAY request plays from. These headers may only be used
in PLAY responses. See Section 5.3.2.4 and Annex G of <xref
target="PSS-234"></xref> for normative definitions.</t>
<t>The three "x-" headers were defined in 3GPP Release 5. When it was
realized that they should not have been given "x-" names it was too
late rename them due to deployment.</t>
<t>The RTSP headers are: <list style="symbols">
<t>x-predecbufsize</t>
<t>x-initpredecbufperiod</t>
<t>x-initpostdecbufperiod</t>
<t>3gpp-videopostdecbufsize</t>
</list></t>
</section>
<section title="Integrity Protection">
<t>The integrity-protection mechanism defined in PSS Annex K uses the
"3GPP-Freshness-Token" (See Section K.2.2.4 of <xref
target="PSS-234"></xref>) RTSP header to carry a freshness token in
DESCRIBE requests.</t>
</section>
<section title="RTSP URI Extension">
<t>The PSS specification also defines syntax for referencing tracks
within the "3GP" file format <xref target="PSS-3GP"></xref>. The 3GP
format is based on the ISO base media file format and defined in
several different profiles, including a streaming-server profile, in
Release 6.</t>
<t>This syntax is fully contained within the generic URI syntax
defined for RTSP URIs. It is only a syntax restriction server
manufacturers follow to allow clients or proxies to understand what
encodes the track number in the URI. This is provided for information
only.</t>
<t>To identify a track within a 3GP file the last URI segment has to
contain a structure that is <alpha string>=<track nr> (See
5.3.3.1 of <xref target="PSS-234"></xref>).</t>
</section>
<section title="Fast Start-up and Content Switching">
<t>Release 7 of PSS defines a number of extensions in terms of headers
and option tags (See Section 5.5 of <xref target="PSS-234"></xref>)
for support of fast start-up and switching of content for on-demand
and live applications built on top of PSS. Clients are enabled to
reuse the existing RTSP control session and RTP resources while
switching to new content.</t>
<t>The RTSP headers are: <list style="symbols">
<t>Switch-Stream</t>
<t>SDP-Requested</t>
<t>Pipelined-Requests</t>
</list>The RTSP option tags are:<list style="symbols">
<t>3gpp-pipelined</t>
<t>3gpp-switch</t>
<t>3gpp-switch-req-sdp</t>
<t>3gpp-switch-stream</t>
</list></t>
</section>
</section>
<section anchor="IANA" title="IANA Considerations">
<t></t>
<section anchor="sec-iana-sdp" title="SDP Registrations">
<t>IANA is requested to register the SDP attributes listed below in
the registry at http://www.iana.org/assignments/sdp-parameters. The
contact person for this registration is Magnus Westerlund
(magnus.westerlund@ericsson.com) Phone number +46 8 719 0000.</t>
<t><figure>
<artwork><![CDATA[SDP Protocol Identifiers ("proto"):
Name: UDP/MBMS-FEC/RTP/AVP
Long form: 3GPP MBMS FEC protected RTP/AVP over UDP
Type of name: proto
Purpose: 3GPP MBMS defines a mechanism to provide block-
based FEC for UDP-based traffic. This solution
uses the SDP protocol "proto" identifier to
identify the media streams that use the FEC
shim layer. This protocol identifier indicates
that the FEC protected data is RTP using the
AVP profile.
Reference: RFCXXXX, 3GPP TS 26.346
Name: UDP/MBMS-FEC/RTP/SAVP
Long form: 3GPP MBMS FEC protected RTP/SAVP over UDP
Type of name: proto
Purpose: 3GPP MBMS defines a mechanism to provide block-
based FEC for UDP-based traffic. This solution
uses the SDP protocol "proto" identifier to
identify the media streams that use the FEC
shim layer. This protocol identifier indicates
that the FEC protected data is RTP using the
Secure AVP profile (SAVP).
Reference: RFCXXXX, 3GPP TS 26.346
Name: UDP/MBMS-REPAIR
Long form: 3GPP MBMS FEC repair symbols over UDP
Type of name: proto
Purpose: 3GPP MBMS defines a mechanism to provide block-
based FEC for UDP-based traffic. This solution
uses the SDP protocol "proto" identifier to
identify the media streams that use the FEC
shim layer. This protocol identifier indicates
that the FEC repair data is sent over UDP.
Reference: RFCXXXX, 3GPP TS 26.346
]]></artwork>
</figure></t>
<t><figure>
<artwork><![CDATA[ SDP Attribute ("att-field"):
Attribute name: X-predecbufsize
Long form: Pre-decoder buffer size
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.1
Reference: 3GPP TS 26.234, Section 5.3.3.2
Values: See Reference
Attribute name: X-initpredecbufperiod
Long form: Pre-decoder initial buffering period
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.1
Reference: 3GPP TS 26.234, Section 5.3.3.2
Values: See Reference
Attribute name: X-initpostdecbufperiod
Long form: Post-decoder initial buffering period
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.1
Reference: 3GPP TS 26.234, Section 5.3.3.2
Values: See Reference
Attribute name: X-decbyterate
Long form: Peak decoding rate in bytes per second
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.1
Reference: 3GPP TS 26.234, Section 5.3.3.2
Values: See Reference
Attribute name: 3gpp-videopostdecbufsize
Long form: Post decoder buffer size
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.1
Reference: 3GPP TS 26.234, Section 5.3.3.2
Values: See Reference
Attribute name: framesize
Long form: Maximum Video Frame Size
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.2
Reference: 3GPP TS 26.234, Section 5.3.3.2
Values: See Reference
Attribute name: 3GPP-Integrity-Key
Long form: 3GPP DRM Integrity Key
Type of name: att-field
Type of attribute: Session level only
Subject to charset: No
Purpose: See Section 4.3
Reference: 3GPP TS 26.234, Sections 5.3.3.2 and K.2.2.1
Values: See Reference
Attribute name: 3GPP-SRTP-Config
Long form: 3GPP DRM SRTP Configuration
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.3
Reference: 3GPP TS 26.234, Sections 5.3.3.2 and K.2.2.2
Values: See Reference
Attribute name: 3GPP-SDP-Auth
Long form: 3GPP DRM Integrity SDP Authentication
Type of name: att-field
Type of attribute: Session level only
Subject to charset: No
Purpose: See Section 4.3
Reference: 3GPP TS 26.234, Sections 5.3.3.2 and K.2.2.3
Values: See Reference
Attribute name: alt
Long form: Alternative SDP line
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.4
Reference: 3GPP TS 26.234, Section 5.3.3.3
Values: See Reference
Attribute name: alt-default-id
Long form: Default alternative ID
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.4
Reference: 3GPP TS 26.234, Section 5.3.3.3
Values: See Reference
Attribute name: alt-group
Long form: Grouping of SDP Line alternatives
Type of name: att-field
Type of attribute: Session level only
Subject to charset: No
Purpose: See Section 4.4
Reference: 3GPP TS 26.234, Section 5.3.3.4
Values: See Reference
Attribute name: 3GPP-Adaptation-Support
Long form: 3GPP Adaptation Support
Type of name: att-field
Type of attribute: Media level only
Subject to charset: No
Purpose: See Section 4.5
Reference: 3GPP TS 26.234, Section 5.3.3.5
Values: See Reference
Attribute name: 3GPP-QoE-Metrics
Long form: 3GPP Quality of Experience Metrics
Type of name: att-field
Type of attribute: Session and Media level
Subject to charset: No
Purpose: See Section 4.6
Reference: 3GPP TS 26.234, Section 5.3.3.6
Values: See Reference
Attribute name: 3GPP-Asset-Information
Long form: 3GPP Asset Information
Type of name: att-field
Type of attribute: Session and Media level
Subject to charset: No
Purpose: See Section 4.7
Reference: 3GPP TS 26.234, Section 5.3.3.7
Values: See Reference
Attribute name: mbms-mode
Long form: MBMS Bearer Mode Declaration
Type of name: att-field
Type of attribute: Session and Media level
Subject to charset: No
Purpose: See Section 5.1
Reference: 3GPP TS 26.346, Section 7.3.2.7
Values: See Reference
Attribute name: mbms-flowid
Long form: FEC Flow ID
Type of name: att-field
Type of attribute: Media level
Subject to charset: No
Purpose: See Section 5.2
Reference: 3GPP TS 26.346, Section 8.3.1.9
Values: See Reference
Attribute name: mbms-repair
Long form: MBMS Repair
Type of name: att-field
Type of attribute: Session and Media level
Subject to charset: No
Purpose: See Section 5.3
Reference: 3GPP TS 26.346, Section 8.3.1.8
Values: See Reference
]]></artwork>
</figure></t>
</section>
<section anchor="sec-iana-rtsp" title="RTSP Registrations">
<t>IANA is requested to register the RTSP headers listed below in the
RTSP 1.0 registry table "RTSP/1.0 Headers" at:</t>
<t>http://www.iana.org/assignments/rtsp-parameters.</t>
<t>Note: This registry requires Standards document, preferably an IETF
RFC. The document that defines the registered headers below is a
technical standards document from 3GPP, although the request for
registration is submitted using this document to achieve further
information spreading within IETF.</t>
<t>The contact person for this registration is Magnus Westerlund
(magnus.westerlund@ericsson.com) Phone number +46 8 719 0000.</t>
<t><figure>
<artwork><![CDATA[ Header Name: 3GPP-Freshness-Token
Purpose: See Section K.2 of 3GPP TS 26.234
Methods: DESCRIBE Requests
Reference: Section K.2.2.4 of 3GPP TS 26.234
Values: See Reference
Header Name: 3GPP-Link-Char
Purpose: See Section 5.3.2.1 of 3GPP TS 26.234
Methods: SETUP, PLAY, OPTIONS or SET_PARAMETER Requests
Reference: Section 5.3.2.1 of 3GPP TS 26.234
Values: See Reference
Header Name: 3GPP-Adaptation
Purpose: See Section 5.3.2.2 of 3GPP TS 26.234
Methods: SETUP, PLAY, OPTIONS, or SET_PARAMETER Requests
and Responses
Reference: Section 5.3.2.2 of 3GPP TS 26.234
Values: See Reference
Header Name: 3GPP-QoE-Metrics
Purpose: See Section 5.3.2.3.1 of 3GPP TS 26.234
Methods: SETUP, PLAY, OPTIONS, or SET_PARAMETER Requests
and Responses
Reference: Section 5.3.2.3.1 of 3GPP TS 26.234
Values: See Reference
Header Name: 3GPP-QoE-Feedback
Purpose: See Section 5.3.2.3.2 of 3GPP TS 26.234
Methods: SET_PARAMETER, PAUSE, or TEARDOWN Requests
Reference: Section 5.3.2.3.2 of 3GPP TS 26.234
Values: See Reference
Header Name: Switch-Stream
Purpose: See Section 5.5.4.2 of 3GPP TS 26.234
Methods: PLAY Requests and Responses
Reference: Section 5.5.4.2 of 3GPP TS 26.234
Values: See Reference
Header Name: SDP-Requested
Purpose: See Section 5.5.4.4 of 3GPP TS 26.234
Methods: PLAY Requests
Reference: Section 5.5.4.4 of 3GPP TS 26.234
Values: See Reference
Header Name: Pipelined-Requests
Purpose: See Section 5.5.3 of 3GPP TS 26.234
Methods: SETUP and PLAY Requests
Reference: Section 5.5.3 of 3GPP TS 26.234
Values: See Reference
Header Name: x-predecbufsize
Purpose: See Section 5.3.2.4 of 3GPP TS 26.234
Methods: PLAY Response
Reference: Section 5.3.2.4 of 3GPP TS 26.234
Values: See Reference
Header Name: x-initpredecbufperiod
Purpose: See Section 5.3.2.4 of 3GPP TS 26.234
Methods: PLAY Response
Reference: Section 5.3.2.4 of 3GPP TS 26.234
Values: See Reference
Header Name: x-initpostdecbufperiod
Purpose: See Section 5.3.2.4 of 3GPP TS 26.234
Methods: PLAY Response
Reference: Section 5.3.2.4 of 3GPP TS 26.234
Values: See Reference
Header Name: 3gpp-videopostdecbufsize
Purpose: See Section 5.3.2.4 of 3GPP TS 26.234
Methods: PLAY Response
Reference: Section 5.3.2.4 of 3GPP TS 26.234
Values: See Reference
Header Name: Supported
Purpose: See Section 5.5.2.2.2 of 3GPP TS 26.234
Methods: Any Request and Response
Reference: Section 5.5.2.2.2 of 3GPP TS 26.234
Values: See Reference
]]></artwork>
</figure>IANA is requested to register the RTSP Option tags (option
tags) listed below in the RTSP 1.0 registry table for RTSP/1.0 Option
Tags</t>
<t>http://www.iana.org/assignments/rtsp-parameters.</t>
<t><figure>
<artwork><![CDATA[ Option tag: 3gpp-pipelined
Purpose: See Section 5.5.3 of 3GPP TS 26.234
Applies to: Client and Server
Reference: Section 5.5.3 of 3GPP TS 26.234
Values: See Reference
Option tag: 3gpp-switch
Purpose: See Section 5.5.4.2 of 3GPP TS 26.234
Applies to: Client and Server
Reference: Section 5.5.4.2 of 3GPP TS 26.234
Values: See Reference
Option tag: 3gpp-switch-req-sdp
Purpose: See Section 5.5.4.4 of 3GPP TS 26.234
Applies to: Client and Server
Reference: Section 5.5.4.4 of 3GPP TS 26.234
Values: See Reference
Option tag: 3gpp-switch-stream
Purpose: See Section 5.5.4.5 of 3GPP TS 26.234
Applies to: Client and Server
Reference: Section 5.5.4.5 of 3GPP TS 26.234
Values: See Reference
]]></artwork>
</figure></t>
</section>
</section>
<section anchor="Security" title="Security Considerations">
<t>SDP attributes are subject to modification by an attacker unless they
are integrity protected and authenticated. The security consideration of
the SDP specification <xref target="RFC4566"></xref> should be reviewed
in this regard. The registered SDP attributes are vulnerable to
modification attacks or removal, which may result in problems of serious
nature, including failure to use service and reduced quality.</t>
<t>The registered RTSP headers are also vunerable to insertion, deletion
or modification attacks similar to SDP attributes. Also in this case it
can result in failure of the service or reduced quality of streaming
content.</t>
<t>The three SDP protocol identifiers do not by themselves introduce any
additional security threats that don't exist for other protocol
identifiers in SDP. The media stream and the protocols identified by the
protocol identifier may however contain security issues by
themselves.</t>
</section>
<section anchor="Acknowledgements" title="Acknowledgements">
<t></t>
</section>
</middle>
<back>
<references title="Normative References">
<reference anchor="PSS-234">
<front>
<title>Transparent end-to-end Packet-switched Streaming Service
(PSS); Protocols and codecs,</title>
<author fullname="3GPP TS 26.234 version 7.7.0 (2009-03)"
surname="3GPP TS 26.234 version 7.7.0 (2009-03)">
<organization>3rd Generation Partnership Project
(3GPP)</organization>
</author>
<date />
</front>
</reference>
<reference anchor="PSS-3GP">
<front>
<title>Transparent end-to-end packet switched streaming service
(PSS); 3GPP file format (3GP)</title>
<author fullname="3GPP TS 26.244 version 7.3.0 (2007-12)"
surname="3GPP TS 26.244 version 7.3.0 (2007-12)">
<organization>3rd Generation Partnership Project
(3GPP)</organization>
</author>
<date />
</front>
</reference>
<reference anchor="MBMS">
<front>
<title>Multimedia Broadcast/Multicast Service (MBMS); Protocols and
codecs</title>
<author fullname="3GPP TS 26.346 version 7.10.0 (2009-03)"
surname="3GPP TS 26.346 version 7.10.0 (2009-03)">
<organization abbrev="3GPP">3rd Generation Partnership Project
(3GPP)</organization>
</author>
<date />
</front>
</reference>
<?rfc include='reference.RFC.0768'?>
<?rfc include="reference.RFC.2119"?>
<?rfc include='reference.RFC.3551'?>
<?rfc include='reference.RFC.3711'?>
</references>
<references title="Informative References">
<reference anchor="PSS-233">
<front>
<title>Transparent end-to-end packet switched streaming service
(PSS) General Description</title>
<author fullname="3GPP TS 26.233 version 7.0.0 (2007-06)"
surname="3GPP TS 26.233 version 7.0.0 (2007-06)">
<organization>rd Generation Partnership Project
(3GPP)</organization>
</author>
<date />
</front>
</reference>
<reference anchor="AES">
<front>
<title>"Advanced Encryption Standard (AES)", FIPS PUB 197,
http://www.nist.gov/aes/.</title>
<author fullname="NIST">
<organization></organization>
</author>
<date />
</front>
</reference>
<?rfc include='reference.RFC.2326'?>
<?rfc include='reference.RFC.3264'?>
<?rfc include='reference.RFC.4566'?>
<?rfc include='reference.RFC.4648'?>
</references>
<references title=""></references>
</back>
</rfc>| PAFTECH AB 2003-2026 | 2026-04-24 05:41:49 |