1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T Q.715TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (04/2002) SERIES Q: SWITCHING AND SIGNALLING Specifications of Signalling System No. 7 Signalling connection control part (SCCP) Signalling connection control part user guide ITU-T Recommendation Q.715
2、ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3 INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60Q.99 CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Q.100Q.119 SPECIFICA
3、TIONS OF SIGNALLING SYSTEM No. 4 Q.120Q.139 SPECIFICATIONS OF SIGNALLING SYSTEM No. 5 Q.140Q.199 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 Q.250Q.309 SPECIFICATIONS OF SIGNALLING SYSTEM R1 Q.310Q.399 SPECIFICATIONS OF SIGNALLING SYSTEM R2 Q.400Q.499 DIGITAL EXCHANGES Q.500Q.599 INTERWORKING OF SIGNA
4、LLING SYSTEMS Q.600Q.699 SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.799 General Q.700 Message transfer part (MTP) Q.701Q.709 Signalling connection control part (SCCP) Q.711Q.719 Telephone user part (TUP) Q.720Q.729 ISDN supplementary services Q.730Q.739 Data user part Q.740Q.749 Signalling Sys
5、tem No. 7 management Q.750Q.759 ISDN user part Q.760Q.769 Transaction capabilities application part Q.770Q.779 Test specification Q.780Q.799 Q3 INTERFACE Q.800Q.849 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.850Q.999 PUBLIC LAND MOBILE NETWORK Q.1000Q.1099 INTERWORKING WITH SATELLITE MOBILE SYSTEM
6、S Q.1100Q.1199 INTELLIGENT NETWORK Q.1200Q.1699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.1700Q.1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) Q.1900Q.1999 BROADBAND ISDN Q.2000Q.2999 For further details, please refer to the list of ITU-T Recommendatio
7、ns. ITU-T Rec. Q.715 (04/2002) i ITU-T Recommendation Q.715 Signalling connection control part user guide Summary This Recommendation gives guidance to Administrations, specifiers of SCCP applications and implementors on a number of specific issues related to the incorporation of SCCP in actual netw
8、orks. These guidelines aim to provide a common understanding and hence to enhance the interoperability between networks and implementations. The aim is to give guidance only, it is not intended to extend, change, nor restrict the normative clauses in ITU-T Recs. Q.711 to Q.714. The following topics
9、are covered in this Recommendation: Compatibility issues: This Recommendation identifies changes between the different revisions of the SCCP Recommendations and discusses the effect on the interaction between implementations according to the different revisions. Where incompatibilities are unavoidab
10、le, engineering measures and evolution strategies are considered. Addressing issues: The meaning of the different addressing parameters and options is explained. A procedure is provided so that an application specifier can derive the needs and requirements on the addressing in the underlying SCCP la
11、yer. Networking issues: The possibilities of SCCP routing and management are explored to create particular network structures. Also networking issues pertaining to connectionless or connection oriented services are discussed. Architecture and interworking issues related to broadband SCCP enhancement
12、s are also covered. Source ITU-T Recommendation Q.715 was revised by ITU-T Study Group 11 (2001-2004) and approved under the WTSA Resolution 1 procedure on 13 April 2002. Keywords Addressing, congestion, routing, SCCP, Signalling System No. 7, user guide. ii ITU-T Rec. Q.715 (04/2002) FOREWORD The I
13、nternational Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recomm
14、endations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The a
15、pproval 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 necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administ
16、ration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property
17、 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 had not received notice of int
18、ellectual 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 2002 All rights reserved. No part of this
19、publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. Q.715 (04/2002) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 3.1 Terms defined by this Recommendation 2 3.2 Terms defined in other Recommendations. 3 4 Abbreviations 4 5 Con
20、ventions 5 6 Compatibility issues . 5 6.1 Overview of differences between editions . 5 6.1.1 Differences between Red Book and Blue Book 5 6.1.2 Differences between Blue Book and the 1993 edition 7 6.1.3 Differences between the 1993 edition and 1996 edition 8 6.1.4 Differences between the 1996 editio
21、n and 2001 edition 10 6.2 Interworking problems . 11 6.2.1 Red Book to Blue Book interworking . 11 6.2.2 Blue Book to 1993 edition interworking. 14 6.2.3 1993 edition to 1996 edition interworking . 16 6.2.4 1996 edition to 2001 edition interworking . 21 6.3 Compatibility test and message change proc
22、edures . 21 7 Use of addressing parameters . 22 7.1 Description of addressing parameters in primitives . 22 7.1.1 Subsystem numbers (3.4.2.2/Q.713) 23 7.1.2 The global title 24 7.1.3 Use of non-standardized TT and SSN in the international network. 28 7.2 Procedure to derive SCCP-addressing requireme
23、nts 29 7.3 Global title conversion operations 30 7.4 The generic numbering plan. 31 7.4.1 Example 32 7.4.2 Considerations for introduction of the generic numbering plan. 33 7.5 Considerations for the SCCP users on the inputs for global title. 33 8 SCCP networking aspects. 33 8.1 Network structures i
24、n view of SCCP management capabilities. 33 8.1.1 Configurations of subsystems. 34 8.1.2 Unambiguousaddresses 37 8.1.3 Load distribution 38 iv ITU-T Rec. Q.715 (04/2002) Page 8.1.4 Configurations of relay/gateway nodes 40 8.2 Application of connection-oriented services 40 8.2.1 Coupling of connection
25、 sections (clause 3/Q.714). 40 8.3 Application of connectionless services 41 8.3.1 The return on error procedure (4.2/Q.714). 41 8.3.2 Maximal length supported by SCCP connectionless procedures . 44 8.4 Support of MTP-3b. 45 8.4.1 Protocol architecture. 45 8.4.2 Interworking . 47 9 SCCP congestion h
26、andling . 49 9.1 Assigning importance values to application messages. 49 9.2 Responsibilities for the application 50 9.3 Application of MTP congestion procedures. 51 9.4 Application of SCCP and node congestion procedures 51 9.5 Coordination of congestion control measures between SCCP and other MTP u
27、sers. 51 10 SCCP support for Number Portability 52 ITU-T Rec. Q.715 (04/2002) v Introduction This Recommendation gives guidance to Administrations, protocol specifiers and implementors on a number of issues related to the application of the SCCP protocol in actual networks. Background The SCCP Recom
28、mendations have gone through a number of revisions from the 1984 edition (Red Book), 1988 edition (Blue Book), 1993 edition, 1996 edition up to this edition (2002). During these revisions, incompatibilities were introduced that require extra attention both for the implementation as for the engineeri
29、ng of the networks. These compatibility issues prior to the 1996 edition were not described in the Recommendations. During the revisions of the Recommendations, flexibility in the addressing mechanisms was introduced. Unfortunately, this flexibility leads to some lack of clarity: it is not clear how
30、 these mechanisms can be used in a standardized way to guarantee interworking or future extendibility. This has lead to different philosophies being applied in different regions of the world. This user guide does not intend to make any of these historic approaches obsolete, it merely tries to docume
31、nt what is sensible to do and what is not. SCCP management is another area that is open for interpretation. In this user guide a number of possible network structures and their addressing-requirements are discussed. In practice, not all of these possibilities may be supported by particular implement
32、ations. SCCP congestion was a topic that has long remained for further study. This user guide gives guidelines on how to use the SCCP congestion control measures, specified in the 1996 edition, and further guidelines on how to handle congestion occurring in CCS7 networks. In order to support B-ISDN
33、services via ATM links, the MTP was upgraded to provide for larger message sizes and higher signalling data rates. The SCCP was enhanced (1996 edition) in order to exploit those new capabilities of the “MTP-3b“. ITU-T Rec. Q.715 (04/2002) 1 ITU-T Recommendation Q.715 Signalling connection control pa
34、rt user guide 1 Scope This Recommendation belongs to a set of Recommendations specifying the SCCP protocol (ITU-T Recs. Q.711 1, Q.712 2, Q.713 3, Q.714 4 and Q.716 5). In addition to the protocol aspects in these Recommendations, this additional Recommendation gives guidance to Administrations, spe
35、cifiers of SCCP-applications and implementors on a number of specific issues related to incorporating SCCP in actual networks. These guidelines aim to provide a common understanding and hence enhance interoperability between network and implementations. Specifically, the following areas are currentl
36、y included: a) Compatibility issues: This Recommendation identifies changes between the several revisions to the SCCP Recommendations, discusses their effect on the cooperation between implementations of different versions and, where incompatibilities are unavoidable, identifies engineering measures
37、 and the need for evolutionary strategies to cope with the problems. b) Use of addressing parameters: This Recommendation discusses the meaning of the addressing parameters and options that have been introduced over the years. It provides a procedure that an application specifier can apply to derive
38、 the needs and requirements on the addressing mechanisms in the underlying SCCP layer. c) Network structures: This Recommendation explores the possibilities of SCCP routing and SCCP management procedures to create particular network structures. It discusses the network issues in case of the use of c
39、onnection oriented services (e.g. coupling of connection sections) and connectionless services (e.g. the return on error procedure). Interworking issues between (a part of) an MTP network providing the MTP-3b capabilities (Higher SDU-size and data rate, see ITU-T Rec. Q.2210 16) and one that does no
40、t are described. d) Congestion handling: Guidance is given to application specifiers/implementors on how to handle congestion situations reported from the underlying network layers and how to use the capabilities described in SCCP Recommendations. e) A brief statement regarding SCCPs ability to supp
41、ort Number Portability. The aim of this Recommendation is to give guidance only, it is not intended to extend, change nor restrict the normative clauses in Recommendations protocol (ITU-T Recs. Q.711 1, Q.712 2, Q.713 3, Q.714 4 and Q.716 5. In case of conflict, the latter take precedence, e.g. norm
42、ative aspects of compatibility are described in ITU-T Rec. Q.714. 2 References The following ITU-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 vali
43、d. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent editions of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations
44、 is regularly published. 1 ITU-T Recommendation Q.711 (2001), Functional description of signalling connection control part. 2 ITU-T Rec. Q.715 (04/2002) 2 ITU-T Recommendation Q.712 (1996), Definition and function of signalling connection control part messages. 3 ITU-T Recommendation Q.713 (2001), S
45、ignalling connection control part formats and codes. 4 ITU-T Recommendation Q.714 (2001), Signalling connection control part procedures. 5 ITU-T Recommendation Q.716 (1993), Signalling System No. 7 Signalling Connection Control Part (SCCP) performance. 6 ITU-T Recommendation Q.775 (1997), Guidelines
46、 for using transaction capabilities. 7 ITU-T Recommendation Q.1400 (1993), Architecture framework for the development of signalling and OA ii) definition of SCCP parameters. b) This Recommendation makes use of the following term defined in ITU-T Rec. Q.1400 7: Subsystem number c) This Recommendation
47、 makes use of the following terms defined in ITU-T Rec. Q.713 3 and 2.4/Q.714 4: Global title indicator Routing indicator Encoding scheme Translation type Numbering plan Odd/even indicator d) This Recommendation makes use of the following term defined in ITU-T Rec. X.650 8: Unambiguous e) This Recom
48、mendation makes use of the following terms defined in ITU-T Rec. X.200: Single association control function Application entity f) This Recommendation makes use of the following terms defined in ITU-T Rec. Q.1290: Service Switching Point (SSP) Service Control Point (SCP) Service subscriber 4 ITU-T Re
49、c. Q.715 (04/2002) 4 Abbreviations This Recommendation uses the following abbreviations. AC Authentication Centre AE Application Entity ASE Application Service Element ATM Asynchronous Transfer Mode DPC Destination Point Code EOP End of Optional Parameters ES Encoding Scheme FE Functional Entity GT Global Title GTI Global Title Indicator HLR Home Location Register IMSI International Mobile Subscriber Identity IN Intelligent Network ISDN Integrated Services Digital Network ISUP ISDN
