1、 ETSI TS 129 079 V14.0.0 (2017-04) Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Optimal media routeing within the IP Multimedia Subsystem (IMS); Stage 3 (3GPP TS 29.079 version 14.0.0 Release 14) TECHNICAL SPECIFICATION ETSI ETS
2、I TS 129 079 V14.0.0 (2017-04)13GPP TS 29.079 version 14.0.0 Release 14Reference RTS/TSGC-0329079ve00 Keywords GSM,LTE,UMTS ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non luc
3、ratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present document can be downloaded from: http:/www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or print versions of the
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8、TTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE are Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM
9、Association. ETSI ETSI TS 129 079 V14.0.0 (2017-04)23GPP TS 29.079 version 14.0.0 Release 14Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available f
10、or ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (htt
11、ps:/ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, esse
12、ntial to the present document. Foreword This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP). The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or GSM identities. These should be interpr
13、eted as being references to the corresponding ETSI deliverables. The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under http:/webapp.etsi.org/key/queryform.asp. Modal verbs terminology In the present document “shall“, “shall not“, “should“, “should not“, “may“, “need not“
14、, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. ETSI ETSI TS 129 079 V14.0.0 (2017-04)
15、33GPP TS 29.079 version 14.0.0 Release 14Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 5g31 Scope 6g32 References 6g33 Definitions, symbols and abbreviations . 7g33.1 Definitions 7g33.2 Symbols 8g33.3 Abbreviations . 8g34 General . 8g35 Common SDP Proce
16、dures 9g35.1 General . 9g35.2 Encapsulation of previous SDP information 9g35.2.1 Media level information 9g35.2.2 Session level information 9g35.3 Determination of codec related SDP information associated to a previous realm instance 10g35.4 Modifying codec related information . 11g35.4.1 Modifying
17、the format list 11g35.4.2 Modifying preferred configurations 11g35.5 Additional handling for SDP answer with actual configuration . 12g35.6 Procedures specific to OMR attributes . 12g35.6.1 General 12g35.6.2 instance-number 12g35.6.3 Session and media checksum calculation . 13g35.7 Roaming architect
18、ure for voice over IMS with local breakout. 13g35.8 II-NNI traversal scenario 13g36 IMS-ALG procedures . 13g36.1 IMS-ALG handling of initial SDP offer . 13g36.1.1 General 13g36.1.2 Validating the received SDP offer 14g36.1.3 Deciding whether to allocate a primary local MR and if any previous MR can
19、be bypassed . 14g36.1.4 Bypassing previous MRs 16g36.1.5 Bypassing no previous MRs . 16g36.1.6 Allocating a primary local MR . 16g36.1.7 Allocating no primary local MR . 17g36.1.8 Allocating secondary local MRs . 17g36.1.9 Forwarding SDP offer . 18g36.2 IMS-ALG handling of initial SDP answer . 18g36
20、.2.1 General 18g36.2.2 IMS-ALG bypasses an allocated transcoding MR 18g36.2.3 IMS-ALG allocates a local transcoding MR when performing proactive transcoding without resource reservation 19g36.2.4 IMS-ALG determines steps required to complete the handling of the SDP answer . 20g36.2.5 Receiving an un
21、specified connection address and a visited-realm instance . 20g36.2.6 Receiving an unspecified connection address and a secondary-realm instance 21g36.2.7 Other handling when no primary local MR allocated . 21g36.2.8 Retaining a primary or secondary local MR . 21g36.2.9 Forwarding the SDP answer . 2
22、2g36.3 IMS-ALG OMR media resource operations 23g36.3.1 General 23g36.3.2 IMS-ALG operations 23g3ETSI ETSI TS 129 079 V14.0.0 (2017-04)43GPP TS 29.079 version 14.0.0 Release 146.4 Handling of connected IP realms . 23g37 UA Procedures . 24g37.1 UA sending an initial SDP offer . 24g37.2 UA receiving an
23、 initial SDP offer 24g37.2.1 General 24g37.2.2 Validating the incoming SDP offer . 24g37.2.3 UA may choose an alternate realm instance to bypass an upstream MR 25g37.3 UA receiving an initial SDP answer . 25g37.3.1 General 25g37.3.2 Receiving SDP answer with an unspecified connection address 25g37.3
24、.3 Receiving SDP answer with a valid connection address. 25g37.4 UA OMR media resource operations . 26g37.4.1 General 26g37.4.2 UA operations . 26g37.5 Handling of connected IP realms . 26g38 Subsequent SDP offer/answer transactions 26g38.1 General . 26g38.2 IMS-ALG and UA subsequent SDP offer proce
25、dures 27g38.3 IMS-ALG and UA subsequent SDP answer procedures 27g38.4 Handling media resources during a subsequent SDP offer/answer transaction 28g3Annex A (informative): Signalling flows 29g3A.1 Scope of signalling flows . 29g3A.2 Introduction 29g3A.3 Media bypassing all IMS-ALGs . 30g3A.3.1 Genera
26、l . 30g3A.3.2 Message flow 30g3A.4 IMS-ALG allocates a local transcoding MR when performing proactive transcoding without resource reservation 42g3A.4.1 General . 42g3A.4.2 Message flow 42g3A.5 IMS-ALG bypasses an allocated transcoding MR . 62g3A.5.1 General . 62g3A.5.2 Message flow 62g3A.6 Loopback
27、 routeing via an intermediate network 75g3A.6.1 General . 75g3A.6.2 Message flow 76g3Annex B (informative): Change history . 90g3History 91g3ETSI ETSI TS 129 079 V14.0.0 (2017-04)53GPP TS 29.079 version 14.0.0 Release 14Foreword This Technical Specification has been produced by the 3rdGeneration Par
28、tnership Project (3GPP). The contents of the present document are subject to continuing work within the TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an identifying change of release date and an in
29、crease in version number as follows: Version x.y.z where: x the first digit: 1 presented to TSG for information; 2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is incremented for all changes of substance, i.e. technical enhancem
30、ents, corrections, updates, etc. z the third digit is incremented when editorial only changes have been incorporated in the document. ETSI ETSI TS 129 079 V14.0.0 (2017-04)63GPP TS 29.079 version 14.0.0 Release 141 Scope The present document defines optional Optimal Media Routeing (OMR) procedures t
31、hat can be applied by entities in the IP Multimedia Subsystem (IMS) that control media resources and are capable of manipulating the Session Description Protocol (SDP) as defined by IETF RFC 4566 6. The OMR procedures in the present specification relate to the handling of OMR-specific SDP attributes
32、 that are documented in TS 24.229 4. The OMR procedures use SDP offer/answer related procedures in IETF RFC 3264 5 and in 3GPP TS 24.229 4 in a backward-compatible manner. The 3GPP network architecture, including the configuration and network entities of the IMS, is defined in 3GPP TS 23.002 2. The
33、Stage 2 of the IMS is defined 3GPP TS 23.228 3. Annex Q of 3GPP TS 23.228 3 documents the architecture and call flows for OMR. The OMR procedures in this document are applicable to the following IMS entities that perform as an IMS-ALG or UA according to 3GPP TS 24.229 4 and that control media resour
34、ces: - an IBCF acting as an IMS-ALG; - a P-CSCF acting as IMS-ALG; - an AS acting as B2BUA and adapting IMS-ALG procedures to control an MRF; - an AS acting as B2BUA and adapting UA procedures to control an MRF; and - an MGCF acting as UA. NOTE 1: An AS acting as B2BUA to perform application functio
35、ns such as conferencing or announcements will normally perform separate originating and terminating UA procedures, treating the media resource as an endpoint. An AS acting as B2BUA offering transcoding options will typically follow IMS-ALG procedures. NOTE 2: The controlled media resource can be a T
36、rGW, IMS-AGW, MRF, or a media function of the entity performing OMR. The OMR procedures are not applicable for an UE. 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. - References are either specific (identi
37、fied by date of publication, edition number, version number, etc.) or non-specific. - For a specific reference, subsequent revisions do not apply. - For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific refe
38、rence implicitly refers to the latest version of that document in the same Release as the present document. 1 3GPP TR 21.905: “Vocabulary for 3GPP Specifications“. 2 3GPP TS 23.002: “Network architecture“. 3 3GPP TS 23.228: “IP multimedia subsystem; Stage 2“. 4 3GPP TS 24.229: “IP multimedia call co
39、ntrol protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3“. 5 IETF RFC 3264: “An Offer/Answer Model with Session Description Protocol (SDP)“. 6 IETF RFC 4566: “SDP: Session Description Protocol“. ETSI ETSI TS 129 079 V14.0.0 (2017-04)73GPP TS 29.079 ve
40、rsion 14.0.0 Release 147 IETF RFC 2617: “HTTP Authentication: Basic and Digest Access Authentication“. 8 IETF RFC 3605: “Real Time Control Protocol (RTCP) attribute in Session Description Protocol (SDP)“. 9 3GPP TS 29.238: “Interconnection Border Control Functions (IBCF) Transition Gateway (TrGW) in
41、terface, Ix Interface; Stage 3“. 10 3GPP TS 29.334: “IMS Application Level Gateway (IMS-ALG) IMS Access Gateway (IMS-AGW); Iq Interface; Stage 3“. 11 IETF RFC 4240: “Basic Network Media Services with SIP“. 12 IETF RFC 3260: “Media Control Channel Framework“. 13 IETF RFC 6505: “A Mixer Control Packag
42、e for the media Control Channel Framework“. 14 3GPP TS 29.332: “Media Gateway Control Function (MGCF) IM Media Gateway Mn Interface“. 15 3GPP TS 23.334: “IP Multimedia Subsystem (IMS) Application Level Gateway (IMS-ALG) IMS Access Gateway (IMS-AGW) interface: Procedures descriptions“. 16 3GPP TS 29.
43、162: “Interworking between the IM CN subsystem and IP networks“. 17 3GPP TS 29.163: “Interworking between the IP Multimedia (IM) Core Network (CN) subsystem and Circuit Switched (CS) networks“. 18 IETF RFC 5552: “SIP Interface to VoiceXML Media Services“. 19 IETF RFC 4117: “Transcoding Services Invo
44、cation in the Session Initiation Protocol (SIP) Using Third Party Call Control (3pcc)“. 20 IETF RFC 5939: “Session Description Protocol (SDP) Capability Negotiation“. 21 IETF RFC 2234: “Augmented BNF for Syntax Specification: ABNF“. 22 IETF RFC 7549: 3GPP SIP URI Inter Operator Traffic Leg parameter
45、“. 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the terms and definitions given in TR 21.905 1, and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 1. Codec:
46、A media configuration for a media line in SDP that is specified by one or more formats in the format list of the m-line, by one or more preferred configurations (pcfg) associated with the media line, or by a combination of both. Codec Change: Any modification to the media configurations for the medi
47、a line in the format list or the list of preferred configurations. Codec List: Either the format list of the m-line, or a combination of all the preferred configurations and the format list for the media line. Connected IP realm: Compared to a reference IP realm, a connected IP realm is one identifi
48、ed with a different unique name where all IP endpoints in the two IP realms are mutually reachable (accessible) by means of IP routeing without address translation. Interconnection between the IP realms may be via direct link, via IP tunnel through other networks, via IP routeing through intermediat
49、e networks, or via any other method of internetworking as long as their IP endpoints are mutually reachable. The property of connectedness is symmetric but not necessarily transitive. In particular, two IP realms connected to a reference IP realm are not necessarily themselves connected. ETSI ETSI TS 129 079 V14.0.0 (2017-04)83GPP TS 29.079 version 14.0.0 Release 14Incoming termination: The termination at an MR in the direction from where an incoming SDP offer is being received at the IMS-ALG that is cont
