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diff --git a/doc/rfc/rfc6064.txt b/doc/rfc/rfc6064.txt new file mode 100644 index 0000000..5e76324 --- /dev/null +++ b/doc/rfc/rfc6064.txt @@ -0,0 +1,1235 @@ + + + + + + +Internet Engineering Task Force (IETF) M. Westerlund +Request for Comments: 6064 P. Frojdh +Category: Informational Ericsson +ISSN: 2070-1721 January 2011 + + + SDP and RTSP Extensions Defined for 3GPP Packet-Switched Streaming + Service and Multimedia Broadcast/Multicast Service + +Abstract + + 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. This document provides information about these + extensions and registers the RTSP and SDP extensions with IANA. + +Status of This Memo + + This document is not an Internet Standards Track specification; it is + published for informational purposes. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Not all documents + approved by the IESG are a candidate for any level of Internet + Standard; see Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc6064. + +Copyright Notice + + Copyright (c) 2011 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + + + + +Westerlund & Frojdh Informational [Page 1] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 + 2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 3. Applicability Statement . . . . . . . . . . . . . . . . . . . 5 + 4. PSS SDP Extensions . . . . . . . . . . . . . . . . . . . . . . 5 + 4.1. Video Buffering Attributes . . . . . . . . . . . . . . . . 5 + 4.2. Video Frame Size Attribute . . . . . . . . . . . . . . . . 6 + 4.3. Integrity-Protection Configuration Attributes . . . . . . 6 + 4.4. The Alternative Attributes . . . . . . . . . . . . . . . . 7 + 4.5. Adaptation Attribute . . . . . . . . . . . . . . . . . . . 7 + 4.6. Quality of Experience Attribute . . . . . . . . . . . . . 7 + 4.7. Asset Information Attribute . . . . . . . . . . . . . . . 8 + 5. MBMS SDP Extensions . . . . . . . . . . . . . . . . . . . . . 8 + 5.1. MBMS Bearer Mode Declaration Attribute . . . . . . . . . . 8 + 5.2. FEC Flow ID Attribute . . . . . . . . . . . . . . . . . . 8 + 5.3. MBMS Repair Attribute . . . . . . . . . . . . . . . . . . 8 + 5.4. SDP Protocol Identifiers for FEC . . . . . . . . . . . . . 8 + 5.4.1. RTP Protocol Identifiers . . . . . . . . . . . . . . . 9 + 5.4.2. FEC Repair Data Identifier . . . . . . . . . . . . . . 9 + 5.5. Video Buffering Attribute . . . . . . . . . . . . . . . . 9 + 6. SDP Offer/Answer Consideration . . . . . . . . . . . . . . . . 9 + 7. PSS RTSP Extensions . . . . . . . . . . . . . . . . . . . . . 10 + 7.1. 3GPP-Link-Char Header . . . . . . . . . . . . . . . . . . 10 + 7.2. 3GPP-Adaptation Header . . . . . . . . . . . . . . . . . . 10 + 7.3. 3GPP-QoE-Metrics Header . . . . . . . . . . . . . . . . . 10 + 7.4. 3GPP-QoE-Feedback Header . . . . . . . . . . . . . . . . . 11 + 7.5. Video Buffer Headers . . . . . . . . . . . . . . . . . . . 11 + 7.6. Integrity Protection . . . . . . . . . . . . . . . . . . . 11 + 7.7. RTSP URI Extension . . . . . . . . . . . . . . . . . . . . 11 + 7.8. Fast Start-Up and Content Switching . . . . . . . . . . . 12 + 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 + 8.1. SDP Registrations . . . . . . . . . . . . . . . . . . . . 12 + 8.2. RTSP Registrations . . . . . . . . . . . . . . . . . . . . 17 + 9. Security Considerations . . . . . . . . . . . . . . . . . . . 20 + 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20 + 10.1. Normative References . . . . . . . . . . . . . . . . . . . 20 + 10.2. Informative References . . . . . . . . . . . . . . . . . . 21 + + + + + + + + + + + + +Westerlund & Frojdh Informational [Page 2] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +1. Introduction + + 3GPP has specified the Packet-switched Streaming Service (PSS) that + uses both RTSP [RFC2326] and SDP [RFC4566]. The service is specified + in technical specifications TS 26.233 [PSS-233] and TS 26.234 + [PSS-234] in Release 4 and subsequent 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 (DRM), progressive download, as + well as a streaming server file format defined in [PSS-3GP]. Fast + start-up and content switching are addressed in Release 7. + + 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 [MBMS]. + Release 7 extends the MBMS User Service to also work with unicast + bearers for interactive and streaming traffic classes. + + In the process of defining these services, there has occasionally + been a need to extend both SDP and RTSP functionalities. These + extensions have mostly been in the form of SDP attributes and RTSP + headers and option tags. 3GPP uses the name "feature 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. + + In Section 5.4, this document defines three SDP protocol identifiers + used in MBMS to enable the usage of block-based FEC. The SDP + protocol identifiers require an RFC to be defined and registered. As + this is an RFC from the IETF stream, any semantic change will require + a new IETF-approved RFC. 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. 3GPP can update the normative definition in future + versions of their specifications. However, to ensure that such a + change is visible in the IETF, at minimum, IANA should be notified + and the reference to the 3GPP specification updated, and preferably + an updated version of this RFC published. + + The document begins with two sections presenting the SDP extensions + for PSS and MBMS, respectively. They are 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 + + + + + +Westerlund & Frojdh Informational [Page 3] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + Section 8.1, and the RTSP headers and option tags in Section 8.2. + For normative descriptions of all SDP and RTSP extensions, we refer + to TS 26.234 [PSS-234] and TS 26.346 [MBMS]. + +1.1. Requirements Language + + 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 RFC 2119 [RFC2119]. + +2. Glossary + + 3GP: 3GPP file format, a multimedia 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 multimedia sessions in PSS, or servers sending + MBMS sessions. + + 3GPP: Third Generation Partnership Project; see + http://www.3gpp.org for more information about this + organization. + + FEC: Forward Error Correction + + MBMS: Multimedia Broadcast/Multicast Service, a service defined by + 3GPP that utilizes broadcast or multicast technology in + combination with unicast for delivery of a wide range of + content to mobile terminals. + + PSS: Packet-switched Streaming Service, a unicast-based streaming + service for delivery of on-demand or live streaming + multimedia content to mobile terminals. + + RTSP: Real Time Streaming Protocol; see [RFC2326]. + + SDP: Session Description Protocol; see [RFC4566]. + + SRTP: Secure Real-time Transport Protocol; see [RFC3711]. + + QoE: Quality of Experience, the quality level of the user + experience of a service. In PSS, this is estimated by a + combination of application-level metrics. + + QoS: Quality of Service, the quality (properties) that the + network provides toward the upper-layer service. + + + + + +Westerlund & Frojdh Informational [Page 4] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +3. Applicability Statement + + This document describes 3GPP-defined extensions to SDP [RFC4566] and + RTSP [RFC2326] 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. + + 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 nor addressed. Usage of these + attributes in other contexts may require further definitions or + clarifications. For example, all SDP attributes lack offer/answer + usage rules [RFC3264], 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. + +4. PSS SDP Extensions + + The PSS specification [PSS-234] defines a number of different SDP + attributes for different purposes. They are listed below, grouped by + their purpose. The text is intentionally not specific enough to + allow implementation from this document. The normative definition is + in the 3GPP technical specification cited. + +4.1. Video Buffering Attributes + + The following attributes are used to provide parameters for the video + buffer model provided in Annex G and Section 5.3.3.2 of [PSS-234]. + The attributes were defined in Release 5 as "X-" attributes and, at + the time, were 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 [RFC4566] + 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. + + All attributes are defined at media level. + + o The "a=X-predecbufsize" attribute provides the size of the pre- + decoder buffer in bytes. + + o The "a=X-initpredecbufperiod" attribute provides the time during + which a receiver should initially buffer, in 90 kHz ticks, before + starting to consume the data in the buffer in order to ensure that + underflow does not occur, assuming correct data delivery. + + + + + + +Westerlund & Frojdh Informational [Page 5] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + o The "a=X-initpostdecbufperiod" attribute provides the initial + buffering period, in 90 kHz ticks, for the post-decoder buffer + present in H.263 and MPEG-4 Visual. + + o 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. + + o The "a=3gpp-videopostdecbufsize" attribute is used to indicate the + value used in determining the H.264 video post-decoder buffer + size. + + Note that complete descriptions of these attributes can be found in + Section 5.3.3.2 of [PSS-234]. + +4.2. Video Frame Size Attribute + + This media-level attribute provides the receiver with the largest + picture size that a specific H.263 payload type will carry within the + session. The attribute has the following form (see Section 5.3.3.2 + of [PSS-234]): + + "a=framesize:<payload type number> <width>-<height>" + +4.3. Integrity-Protection Configuration Attributes + + These attributes are all used to configure the integrity-protection + mechanism defined in Annex K (Sections K.2.2.1, K.2.2.2, and K.2.2.3) + of [PSS-234]. + + o The session-level attribute "a=3GPP-Integrity-Key" carries the + integrity key used to derive SRTP master keys for integrity + protection. The key is protected in different ways depending on a + method identifier. When using Open Mobile Alliance (OMA) DRM key + management, the key is encrypted using AES [AES] before it is + base64 encoded [RFC4648]. + + o 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. + + o 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. + + + + + +Westerlund & Frojdh Informational [Page 6] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +4.4. The Alternative Attributes + + Two media-level 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 [RFC4566] and TIAS [RFC3890], and + language. + + The SDP attributes (see Sections 5.3.3.3 and 5.3.3.4 of [PSS-234]) + are: + + o The media-level attribute "a=alt:<id>:<SDP-Line>" carries any SDP + line and an alternative identifier. + + o The media-level attribute "a=alt-default-id:<id>" identifies the + default configuration to be used in groupings. + + o The session-level attribute "a=alt-group" is used to group + different recommended media alternatives. This allows providing + aggregated properties for the whole group according to the + grouping type. Language and bit-rate are two defined grouping + types. + +4.5. Adaptation Attribute + + The media-level SDP attribute "a=3GPP-Adaptation-Support" (see + Section 5.3.3.5 in [PSS-234]) 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. + +4.6. Quality of Experience Attribute + + The session- and media-level attribute "a=3GPP-QoE-Metrics" (see + Section 5.3.3.6 of [PSS-234]) is used to negotiate the usage of the + QoE metrics. The included parameters indicate which metrics should + be used, over which duration there should be measurements, and how + often reports should be sent. + + + + + +Westerlund & Frojdh Informational [Page 7] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +4.7. Asset Information Attribute + + The session- and media-level attribute "a=3GPP-Asset-Information" + (see Section 5.3.3.7 of [PSS-234]) 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 [PSS-3GP]. + +5. MBMS SDP Extensions + + The MBMS specification [MBMS] defines a number of different SDP + attributes for different purposes. They are informatively listed + below. + +5.1. MBMS Bearer Mode Declaration Attribute + + The session- and media-level attribute "a=mbms-mode" (see Section + 7.3.2.7 of [MBMS]) is used to describe MBMS broadcast mode media. + The attribute may be used at the session level to set the default for + all media and at the media level to specify differences between + media. However, the attribute is never used at the session level + when the session includes MBMS multicast mode media, nor at the media + level to describe MBMS multicast mode media. + +5.2. FEC Flow ID Attribute + + The media-level attribute "a=mbms-flowid" (see Section 8.3.1.9 of + [MBMS]) 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. + +5.3. MBMS Repair Attribute + + The session- and media-level attribute "a=mbms-repair" (see Section + 8.3.1.8 of [MBMS]) is used to provide FEC repair packets with non-FEC + specific parameters. For Release 6, one such parameter is defined to + specify the required minimum receiver buffer time. + +5.4. SDP Protocol Identifiers for FEC + + 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 + + + + + +Westerlund & Frojdh Informational [Page 8] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + streams may be either source streams or repair streams. As required + by SDP [RFC4566], these protocol identifiers are normatively defined + in this document in accordance with their usage specified by 3GPP. + +5.4.1. RTP Protocol Identifiers + + For FEC-protected RTP streams, the following two "proto" identifiers + are defined: + + o UDP/MBMS-FEC/RTP/AVP + + o UDP/MBMS-FEC/RTP/SAVP + + They indicate the usage of UDP [RFC0768] with MBMS FEC source packet + formats, as defined in Section 8.2.2.4 of [MBMS], that transport RTP + packets in accordance with the AVP [RFC3551] or SAVP (Secure RTP) + [RFC3711] profiles, respectively. These protocol identifiers SHALL + use the media formats ("fmt") namespace rules that are used for RTP/ + AVP and RTP/SAVP, respectively. + +5.4.2. FEC Repair Data Identifier + + 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 UDP [RFC0768], FEC repair payload ID, and repair symbols as + specified in Section 8.2.2.5 of [MBMS]. The "fmt" namespace is not + used and SHALL be set to "*". + +5.5. Video Buffering Attribute + + 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 + [MBMS]). + +6. SDP Offer/Answer Consideration + + The usage of the SDP attributes in an offer/answer [RFC3264] context + is not defined. These SDP attributes are defined for use in a + declarative context, and for PSS specifically in the RTSP [RFC2326] + context. + + + + + + + + +Westerlund & Frojdh Informational [Page 9] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +7. PSS RTSP Extensions + + 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. + +7.1. 3GPP-Link-Char Header + + The "3GPP-Link-Char" header (see Section 5.3.2.1 of [PSS-234]) 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: + + o Guaranteed Bandwidth + + o Maximum Bandwidth + + o Maximum Transfer Delay + + The header may be included in RTSP requests using either of the + methods SETUP, PLAY, OPTIONS, or SET_PARAMETER. + +7.2. 3GPP-Adaptation Header + + The "3GPP-Adaptation" header (see Section 5.3.2.2 of [PSS-234]) 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. + + 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. + +7.3. 3GPP-QoE-Metrics Header + + The "3GPP-QoE-Metrics" header (see Section 5.3.2.3.1 of [PSS-234]) is + used to negotiate the usage of the QoE metrics (see Section 11 of + [PSS-234]). + + The header may be included in requests and responses using the SETUP, + SET_PARAMETER, OPTIONS, or PLAY method. + + + + + + + + +Westerlund & Frojdh Informational [Page 10] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +7.4. 3GPP-QoE-Feedback Header + + The "3GPP-QoE-Feedback" header (see Section 5.3.2.3.2 of [PSS-234]) + is used to carry QoE metrics from the client to the server when it + reports, which happens either during or at the end of the media + delivery. + + The header may be included in requests using the SET_PARAMETER, + PAUSE, or TEARDOWN method. + +7.5. Video Buffer Headers + + PSS uses several headers to provide the client with the different + buffer parameters. They provide the buffer status at the point of a + stream from which a PLAY request plays. These headers may only be + used in PLAY responses. See Section 5.3.2.4 and Annex G of [PSS-234] + for normative definitions. + + 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 to rename them due to deployment. + + The RTSP headers are: + + o x-predecbufsize + + o x-initpredecbufperiod + + o x-initpostdecbufperiod + + o 3gpp-videopostdecbufsize + +7.6. Integrity Protection + + The integrity-protection mechanism defined in PSS Annex K uses the + "3GPP-Freshness-Token" RTSP header (see Section K.2.2.4 of [PSS-234]) + to carry a freshness token in DESCRIBE requests. + +7.7. RTSP URI Extension + + The PSS specification also defines syntax for referencing tracks + within the 3GP file format [PSS-3GP]. The 3GP format is based on the + ISO base media file format and is defined in several different + profiles, including a streaming-server profile, in Release 6. + + + + + + + +Westerlund & Frojdh Informational [Page 11] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + This syntax is fully contained within the generic URI syntax defined + for RTSP URIs. It is only a syntax restriction that server + manufacturers follow to allow clients or proxies to understand what + encodes the track number in the URI. This is provided for + information only. + + To identify a track within a 3GP file, the last URI segment has to + contain a structure that is <alpha string>=<track nr>. (See Section + 5.3.3.1 of [PSS-234].) + +7.8. Fast Start-Up and Content Switching + + Release 7 of PSS defines a number of extensions in terms of headers + and option tags (see Section 5.5 of [PSS-234]) 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. + + The RTSP headers are: + + o Switch-Stream + + o SDP-Requested + + o Pipelined-Requests + + The RTSP option tags are: + + o 3gpp-pipelined + + o 3gpp-switch + + o 3gpp-switch-req-sdp + + o 3gpp-switch-stream + +8. IANA Considerations + +8.1. SDP Registrations + + IANA has registered the SDP attributes listed below in the "Session + Description Protocol (SDP) Parameters" registry available from + http://www.iana.org/. + + The contact person for this registration is Magnus Westerlund (email: + magnus.westerlund@ericsson.com; phone: +46 8 719 0000). + + + + + +Westerlund & Frojdh Informational [Page 12] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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: RFC 6064, 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: RFC 6064, 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: RFC 6064, 3GPP TS 26.346 + + 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 + + + + +Westerlund & Frojdh Informational [Page 13] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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 + + + + + + + +Westerlund & Frojdh Informational [Page 14] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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 + + + + + + + +Westerlund & Frojdh Informational [Page 15] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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 + + + + + + + +Westerlund & Frojdh Informational [Page 16] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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 + +8.2. RTSP Registrations + + IANA has registered the RTSP headers listed below in the RTSP/1.0 + Headers table of the "Real Time Streaming Protocol (RTSP)/1.0 + Parameters" registry available from http://www.iana.org/. + + Note: This registry requires a 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. + + The contact person for this registration is Magnus Westerlund (email: + magnus.westerlund@ericsson.com; phone: +46 8 719 0000). + + 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 + + + + + + + +Westerlund & Frojdh Informational [Page 17] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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 + + + + + + + + +Westerlund & Frojdh Informational [Page 18] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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 + + IANA has registered the RTSP Option tags (option tags) listed below + in the RTSP/1.0 Option Tags table of the "Real Time Streaming + Protocol (RTSP)/1.0 Parameters" registry available from + http://www.iana.org/. + + 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 + + + + + +Westerlund & Frojdh Informational [Page 19] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + 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 + +9. Security Considerations + + SDP attributes are subject to modification by an attacker unless they + are integrity protected and authenticated. The security + considerations of the SDP specification [RFC4566] should be reviewed + in this regard. The registered SDP attributes are vulnerable to + modification attacks or removal, which may result in problems of a + serious nature, including failure to use service and reduced quality. + + The registered RTSP headers are also vulnerable to insertion, + deletion, or modification attacks similar to SDP attributes. Also in + this case, attacks can result in failure of the service or reduced + quality of streaming content. + + 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 used protocols + identified and configured by the SDP protocol identifier may, + however, contain security issues by themselves. + +10. References + +10.1. Normative References + + [MBMS] 3GPP TS 26.346 version 7.10.0 (2009-03), "Multimedia + Broadcast/Multicast Service (MBMS); Protocols and codecs". + + [PSS-234] 3GPP TS 26.234 version 7.7.0 (2009-03), "Transparent end- + to-end Packet-switched Streaming Service (PSS); Protocols + and codecs". + + [PSS-3GP] 3GPP TS 26.244 version 7.3.0 (2007-12), "Transparent end- + to-end packet switched streaming service (PSS); 3GPP file + format (3GP)". + + [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, + August 1980. + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + + + + +Westerlund & Frojdh Informational [Page 20] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + + [RFC3551] Schulzrinne, H. and S. Casner, "RTP Profile for Audio and + Video Conferences with Minimal Control", STD 65, RFC 3551, + July 2003. + + [RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. + Norrman, "The Secure Real-time Transport Protocol (SRTP)", + RFC 3711, March 2004. + +10.2. Informative References + + [AES] NIST, "Advanced Encryption Standard (AES)", FIPS PUB 197, + <http://www.nist.gov/itl/fipscurrent.cfm>. + + [PSS-233] 3GPP TS 26.233 version 7.0.0 (2007-06), "Transparent end- + to-end packet switched streaming service (PSS) General + Description". + + [RFC2326] Schulzrinne, H., Rao, A., and R. Lanphier, "Real Time + Streaming Protocol (RTSP)", RFC 2326, April 1998. + + [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model + with Session Description Protocol (SDP)", RFC 3264, + June 2002. + + [RFC3890] Westerlund, M., "A Transport Independent Bandwidth + Modifier for the Session Description Protocol (SDP)", + RFC 3890, September 2004. + + [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session + Description Protocol", RFC 4566, July 2006. + + [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data + Encodings", RFC 4648, October 2006. + + + + + + + + + + + + + + + + + + +Westerlund & Frojdh Informational [Page 21] + +RFC 6064 SDP and RTSP Extensions for 3GPP January 2011 + + +Authors' Addresses + + Magnus Westerlund + Ericsson + Farogatan 6 + Stockholm SE-164 80 + SWEDEN + + Phone: +46 10 7190000 + Fax: +46 10 757 55 50 + EMail: magnus.westerlund@ericsson.com + + + Per Frojdh + Ericsson + Farogatan 6 + Stockholm SE-164 80 + SWEDEN + + Phone: +46 10 7190000 + Fax: +46 10 757 55 50 + EMail: per.frojdh@ericsson.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Westerlund & Frojdh Informational [Page 22] + |