1、 International Telecommunication Union ITU-T J.171.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2005) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS IPCablecom IPCablecom trunking gateway control protocol (TGCP): Profile 1 ITU-T Recommen
2、dation J.171.1 ITU-T Rec. J.171.1 (11/2005) i ITU-T Recommendation J.171.1 IPCablecom trunking gateway control protocol (TGCP): Profile 1 Summary This Recommendation describes an IPCablecom profile of an Application Programming Interface (API) called a Media Gateway Control Interface (MGCI) and a co
3、rresponding protocol (MGCP) for controlling voice-over-IP (VoIP) PSTN gateways from external call control elements. This is one of the two profiles referenced in ITU-T Rec. J.171.0. The second profile is specified in ITU-T Rec. J.171.2. The MGCP assumes a call control architecture where the call con
4、trol “intelligence“ is outside the gateways and handled by external call control elements. The IPCablecom profile as described in this Recommendation will be referred to as the IPCablecom Trunking Gateway Control Protocol (TGCP). Source ITU-T Recommendation J.171.1 was approved on 29 November 2005 b
5、y ITU-T Study Group 9 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. J.171.1 (11/2005) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-
6、T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four ye
7、ars, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the nec
8、essary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. Howev
9、er, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative eq
10、uivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a
11、 claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU
12、had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2006 All rig
13、hts reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. J.171.1 (11/2005) iii CONTENTS Page 1 Scope 1 2 References. 1 2.1 Normative references 1 2.2 Informative references 1 3 Definitions 2 4 Abbreviations and acro
14、nyms 2 5 Convention 2 5.1 Background. 3 6 Introduction 4 6.1 Relation with other IPCablecom standards 5 6.2 Relation to RFC 3435 and ABNF grammar. 6 7 Media Gateway Control Interface (MGCI) 6 7.1 Model and naming conventions 6 7.2 SDP use 12 7.3 Gateway control functions 13 7.4 States, failover and
15、race conditions 36 7.5 Return codes and error codes . 51 7.6 Reason codes 52 7.7 Use of local connection options and connection descriptors 53 8 Media gateway control protocol . 56 8.1 General description. 56 8.2 Command header 57 8.3 Response header formats 69 8.4 Session description encoding . 72
16、8.5 Transmission over UDP . 83 8.6 Piggybacking 85 8.7 Transaction identifiers and three-way handshake 85 8.8 Provisional responses . 86 9 Security. 87 Annex A Event packages 88 A.1 ISUP trunk package 88 Appendix I Mode interactions. 92 Appendix II Example command encodings 94 II.1 NotificationReque
17、st 94 II.2 Notify 94 II.3 CreateConnection . 94 iv ITU-T Rec. J.171.1 (11/2005) Page II.4 ModifyConnection 96 II.5 DeleteConnection (from the Media Gateway Controller) 97 II.6 DeleteConnection (from the trunking gateway). 97 II.7 DeleteConnection (multiple connections from the Media Gateway Controll
18、er) 97 II.8 AuditEndpoint 98 II.9 AuditConnection. 99 II.10 RestartInProgress 99 Appendix III Example Call Flow 101 Appendix IV Endpoint requirements 104 IV.1 Connection modes supported . 104 Appendix V Compatibility information 105 V.1 NCS compatibility 105 V.2 MGCP compatibility 105 Appendix VI AB
19、NF grammar for TGCP 107 Appendix VII Electronic surveillance. 114 VII.1 MGC. 114 VII.2 MG 114 Appendix VIII Example event packages 116 VIII.1 MF FGD Operator Services package . 116 VIII.2 MF Terminating Protocol package. 119 BIBLIOGRAPHY 122 ITU-T Rec. J.171.1 (11/2005) 1 ITU-T Recommendation J.171.
20、1 IPCablecom trunking gateway control protocol (TGCP): Profile 1 1 Scope This Recommendation describes an IPCablecom profile of an Application Programming Interface (API) called a Media Gateway Control Interface (MGCI) and a corresponding protocol (MGCP) for controlling voice-over-IP (VoIP) PSTN gat
21、eways from external call control elements. This is one of the two profiles referenced in ITU-T Rec. J.171.0. The second profile is specified in ITU-T Rec. J.171.2. The MGCP assumes a call control architecture where the call control “intelligence“ is outside the gateways and handled by external call
22、control elements. The IPCablecom profile as described in this Recommendation will be referred to as the IPCablecom Trunking Gateway Control Protocol (TGCP). This Recommendation is based on the IPCablecom network-based call signalling Recommendation (ITU-T Rec. J.162), and IETF RFC 2705, Media Gatewa
23、y Control Protocol (MGCP). This Recommendation, which defines the IPCablecom TGCP protocol, constitutes a specification that is independent of MGCP. The TGCP profile of MGCP is strictly and solely defined by the contents of this Recommendation. 2 References 2.1 Normative references The following ITU
24、-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendatio
25、n are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it,
26、 as a stand-alone document, the status of a Recommendation. ITU-T Recommendation J.161 (Draft, version 2), Audio codec requirements for the provision of bidirectional audio service over cable television networks using cable modems. ITU-T Recommendation J.162 (2005), Network call signalling protocol
27、for the delivery of time-critical services over cable television networks using cable modems. ITU-T Recommendation J.170 (2005), IPCablecom security specification. IETF RFC 2327 (1998), SDP: Session Description Protocol. 2.2 Informative references ITU-T Recommendation E.180/Q.35 (1998), Technical ch
28、aracteristics of tones for the telephone service. ITU-T Recommendation J.163 (2005), Dynamic quality of service for the provision of real-time services over cable television networks using cable modems. ITU-T Recommendation J.171.0 (2005), IPCablecom trunking gateway control protocol (TGCP): Profile
29、s overview. IETF RFC 1889 (1996) RTP: A Transport Protocol for Real-Time Applications. 2 ITU-T Rec. J.171.1 (11/2005) IETF RFC 1890 (1996), RTP Profile for Audio and Video Conferences with Minimal Control. IETF RFC 2543 (1999), SIP: Session Initiation Protocol. IETF RFC 2705 (1999), Media Gateway Co
30、ntrol Protocol (MGCP) Version 1.0. TCP/IP Illustrated, Volume 1 (2001), The Protocols, Addison-Wesley, 1994. 3 Definitions This Recommendation defines the following terms: 3.1 cable modem: The delivery of high-speed data access to customer locations using equipment built in conformance with ITU-T Re
31、cs J.83 and J.112. 3.2 IPCablecom: An ITU-T project that includes an architecture and a series of Recommendations that enable the delivery of real-time services over the cable television networks using cable modems. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations an
32、d acronyms: DNS Domain Name System IP Internet Protocol IPSec Internet Protocol Security ISUP ISDN User Part MGC Media Gateway Controller MGCP Media Gateway Control Protocol MIB Management Information Base MTA Media Terminal Adapter MWD Maximum Waiting Delay NCS Network-based Call Signalling NTP Net
33、work Time Protocol QoS Quality of Service RTCP Real-Time Control Protocol RTO Retransmission Timeout RTP Real-Time Protocol SDP Session Description Protocol SG Signalling Gateway SPI Security Parameters Index 5 Convention If this Recommendation is implemented, the keywords “MUST“ and “SHALL“ as well
34、 as “REQUIRED“ are to be interpreted as indicating a mandatory aspect of this Recommendation. ITU-T Rec. J.171.1 (11/2005) 3 The key words indicating a certain level of significance of particular requirements that are used throughout this Recommendation are summarized as below. “MUST“ This word or t
35、he adjective “REQUIRED“ means that the item is an absolute requirement of this Recommendation. “MUST NOT“ This phrase means that the item is an absolute prohibition of this Recommendation. “SHOULD“ This word or the adjective “RECOMMENDED“ means that there may exist valid reasons in particular circum
36、stances to ignore this item, but the full implications should be understood and the case carefully weighed before choosing a different course. “SHOULD NOT“ This phrase means that there may exist valid reasons in particular circumstances when the listed behaviour is acceptable or even useful, but the
37、 full implications should be understood and the case carefully weighed before implementing any behaviour described with this label. “MAY“ This word or the adjective “OPTIONAL“ means that this item is truly optional. One vendor may choose to include the item because a particular marketplace requires
38、it or because it enhances the product, for example; another vendor may omit the same item. 5.1 Background This Recommendation describes an IPCablecom profile of an application programming interface called a Media Gateway Control Interface (MGCI) and a corresponding protocol (MGCP) for controlling vo
39、ice-over-IP (VoIP) PSTN Gateways from external call control elements. The MGCP assumes a call control architecture where the call control “intelligence“ is outside the gateways and handled by external call control elements. The IPCablecom profile as described in this Recommendation will be referred
40、to as the IPCablecom Trunking Gateway Control Protocol (TGCP) Profile 1. This Recommendation is based on the IPCablecom Network-based Call Signaling (NCS) ITU-T Rec. J.162, the Media Gateway Control Protocol (MGCP) 1.0 IETF RFC 3435 (which was the result of a merge of the IETF draft of Simple Gatewa
41、y Control Protocol and the IETF draft of IP Device Control (IPDC) family of protocols), and input generated by the IPCablecom PSTN Gateway focus team. This Recommendation, which defines the IPCablecom TGCP Protocol, constitutes a document that is independent of MGCP in order to provide a stable refe
42、rence document while meeting current time-to-market demands for such a reference. It is the intent of this Recommendation to be as closely aligned with NCS and MGCP 1.0 as possible for the IPCablecom environment, in order to avoid developing multiple protocols to solve the same problem. This goal ha
43、s been and continues to be pursued through cooperation with the authors of the NCS and MGCP Recommendations. The TGCP profile of MGCP, however, is strictly and solely defined by the contents of this Recommendation. This TGCP profile of MGCP, which will be referred to as the PSTN Trunking Gateway Cal
44、l Signaling Protocol 1.0, TGCP 1.0, the TGCP profile, or simply TGCP in this Recommendation, has been modified from the MGCP 1.0 IETF RFC 2435 in the following ways: The TGCP protocol only aims at supporting IPCablecom voice-over-IP PSTN Gateways. The TGCP protocol supports voice-over-IP PSTN Gatewa
45、ys as defined by IPCablecom. Functionality present in the MGCP 1.0 protocol, which was superfluous to TGCP, has been removed. 4 ITU-T Rec. J.171.1 (11/2005) The TGCP protocol contains extensions and modifications to MGCP. IPCablecom-specific requirements are addressed in TGCP. However, the MGCP arch
46、itecture, and all of the MGCP constructs relevant to PSTN Gateways, have been preserved in TGCP. The TGCP protocol contains minor simplifications from MGCP 1.0. Where several choices were available, and not necessarily needed for a PSTN Gateway in the IPCablecom environment, some simplifications hav
47、e been made for trunking gateway implementations. Although MGCP is not TGCP, and TGCP is not MGCP, the names MGCP and TGCP will be used interchangeably in this Recommendation since this Recommendation is based on MGCP. Unless otherwise stated or inferable by context, the word MGCP shall be taken to
48、mean the TGCP profile of MGCP in this Recommendation. TGCP is designed to meet the protocol requirements for the Media Gateway Controller to Media Gateway interface defined in the IPCablecom architecture. 6 Introduction This Recommendation describes the TGCP profile of an application programming int
49、erface (MGCI) and a corresponding protocol (MGCP) for controlling trunking gateways from external call control elements. A trunking gateway is a network element that provides analog, emulated analog, or digital bearer and channel-associated signalling trunk circuit access to a voice-over-IP (VoIP) network. Trunking gateways are used for interfacing to the PSTN and as such are expected to adhere to the relevant electrical, operational, and signalling standards for the trunk type they implement. The TGCP Recommendation is developed for CLECs, an
