1、INTERNATIONAL TELECOMMUNICATION UNION)45G1341 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU(07/96)SERIES Q: SWITCHING AND SIGNALLINGSpecifications of Signalling System No. 7 Messagetransfer part3IGNALLINGG0NETWORKG0FUNCTIONSG0ANDG0MESSAGESITU-T Recommendation Q.704(Previously CCITT Recommendation)IT
2、U-T Q-SERIES RECOMMENDATIONS37)4#().G0!.$G03).!,).For further details, please refer to ITU-T List of Recommendations.SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60Q.99CLAUSES
3、 APPLICABLE TO ITU-T STANDARD SYSTEMS Q.100Q.119SPECIFICATION OF SIGNALLING SYSTEMS No. 4 AND No. 5 Q.120Q.249SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 Q.250Q.309SPECIFICATIONS OF SIGNALLING SYSTEM R1 Q.310Q.399SPECIFICATIONS OF SIGNALLING SYSTEM R2 Q.400Q.499DIGITAL EXCHANGES Q.500Q.599INTERWORKING
4、 OF SIGNALLING SYSTEMS Q.600Q.699SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.849General Q.700-ESSAGEG0TRANSFERG0PART 1 1 Simplified message transfer part Q.710Signalling connection control part Q.711Q.719Telephone user part Q.720Q.729ISDN supplementary services Q.730Q.739Data user part Q.740Q.7
5、49Signalling System No. 7 management Q.750Q.759ISDN user part Q.760Q.769Transaction capabilities application part Q.770Q.779Test specification Q.780Q.799Q3 interface Q.800Q.849DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.850Q.999PUBLIC LAND MOBILE NETWORK Q.1000Q.1099INTERWORKING WITH SATELLITE MOBI
6、LE SYSTEMS Q.1100Q.1199INTELLIGENT NETWORK Q.1200Q.1999BROADBAND ISDN Q.2000Q.2999ITU-T RECOMMENDATION Q.704SIGNALLING NETWORK FUNCTIONS AND MESSAGESSummaryThis Recommendation describes the functions and procedures for and relating to the transfer ofmessages between the signalling points, which are
7、the nodes of the signalling network. It has beenmodified to allow use by the broadband ISDN User Part in the narrow-band environment, and theSatellite ISDN User Part.SourceITU-T Recommendation Q.704 was revised by ITU-T Study Group 11 (1993-1996) and wasapproved under the WTSC Resolution No. 1 proce
8、dure on the 9th of July 1996.ii Recommendation Q.704 (07/96)FOREWORDITU (International Telecommunication Union) is the United Nations Specialized Agency in the field oftelecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ ofthe ITU. The ITU-T is responsibl
9、e for studying technical, operating and tariff questions and issuingRecommendations on them with a view to standardizing telecommunications on a worldwide basis.The World Telecommunication Standardization Conference (WTSC), which meets every four years,establishes the topics for study by the ITU-T S
10、tudy Groups which, in their turn, produce Recommendationson these topics.The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down inWTSC Resolution No. 1.In some areas of information technology which fall within ITU-Ts purview, the necessary standards areprep
11、ared on a collaborative basis with ISO and IEC.NOTEIn this Recommendation, the expression “Administration“ is used for conciseness to indicate both atelecommunication administration and a recognized operating agency.INTELLECTUAL PROPERTY RIGHTSThe ITU draws attention to the possibility that the prac
12、tice or implementation of this Recommendation mayinvolve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence,validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or othersoutside of the Recommendation devel
13、opment process.As of the date of approval of this Recommendation, the ITU had/had not received notice of intellectualproperty, 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 t
14、herefore strongly urgedto consult the TSB patent database. ITU 1997All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.Recommendation Q.70
15、4 (07/96) iiiCONTENTSPage1 Introduction. 11.1 General characteristics of the signalling network functions. 11.2 Signalling message handling. 11.3 Signalling network management. 22 Signalling message handling. 32.1 General 32.2 Routing label. 42.3 Message routing function 62.3.4 Handling of level 3 m
16、essages 72.3.5 Handling of messages under signalling link congestion 72.4 Message discrimination and distribution functions 83 Signalling network management. 93.1 General 93.2 Status of signalling links. 103.2.2 Signalling link failure 103.2.3 Signalling link restoration . 113.2.4 Signalling link de
17、activation. 113.2.5 Signalling link activation. 113.2.6 Signalling link blocking. 113.2.7 Signalling link unblocking. 113.2.8 Signalling link inhibiting. 163.2.9 Signalling link uninhibiting. 163.3 Procedures used in connection with link status changes 163.3.1 Signalling link failed . 163.3.2 Signal
18、ling link restored 163.3.3 Signalling link deactivated 183.3.4 Signalling link activated 193.3.5 Signalling link blocked 193.3.6 Signalling link unblocked 193.3.7 Signalling link inhibited 193.3.8 Signalling link uninhibited 193.4 Status of signalling routes. 203.4.1 Signalling route unavailability.
19、 203.4.2 Signalling route availability. 20iv Recommendation Q.704 (07/96)Page3.4.3 Signalling route restricted1203.5 Procedures used in connection with route status changes. 203.5.1 Signalling route unavailable 203.5.2 Signalling route available 203.5.3 Signalling route restricted1213.6 Status of si
20、gnalling points. 213.6.1 Signalling point unavailability. 213.6.2 Signalling point availability. 213.7 Procedures used in connection with point status changes 213.7.1 Signalling point unavailable 213.7.2 Signalling point available 223.8 Signalling network congestion 223.8.1 General. 223.8.2 Congesti
21、on status of signalling links. 223.8.3 Procedures used in connection with link congestion status changes. 253.8.4 Congestion status of signalling route sets 253.8.5 Procedures used in connection with route set congestion status changes 264 Signalling traffic management 264.1 General 264.2 Normal rou
22、ting situation. 274.3 Signalling link unavailability 284.4 Signalling link availability 284.5 Signalling route unavailability 294.6 Signalling route availability 294.7 Signalling route restriction1294.8 Signalling point availability 295 Changeover . 295.1 General 295.2 Network configurations for cha
23、ngeover . 305.3 Changeover initiation and actions. 305.4 Buffer updating procedure 325.5 Retrieval and diversion of traffic 325.6 Emergency changeover procedures. 325.7 Procedures in abnormal conditions. 346 Changeback. 34Recommendation Q.704 (07/96) vPage6.1 General 346.2 Changeback initiation and
24、actions 346.3 Sequence control procedure 366.4 Time-controlled diversion procedure 376.5 Procedures in abnormal conditions. 377 Forced rerouting 387.1 General 387.2 Forced rerouting initiation and actions . 388 Controlled rerouting 388.1 General 388.2 Controlled rerouting initiation and actions . 39
25、9 MTP restart . 399.1 General 399.2 Actions in a signalling point whose MTP is restarting. 409.3 Actions in a signalling point X, adjacent to a signalling point Ywhose MTP restarts 419.4 Short term isolations . 429.5 TRA messages and timer T19. 429.6 General rules. 439.7 Sequence diagrams 439.7.1 SP
26、 with restarting MTP according to subclause 9.2 449.7.2 Actions in SP X adjacent to SP Y whose MTP restarts according tosubclause 9.3 4510 Management inhibiting. 4510.1 General 4510.2 Inhibiting initiation and actions 4610.3 Uninhibiting initiation and actions . 4710.3.1 Management-initiated uninhib
27、iting . 4710.3.2 Signalling routing control initiated uninhibiting . 4810.4 Receipt of unexpected management inhibition messages. 4810.5 Management inhibited link status and processor recovery. 4810.6 Inhibit test procedure 4911 Signalling traffic flow control. 4911.1 General 4911.2 Flow control ind
28、ications . 50vi Recommendation Q.704 (07/96)Page11.2.1 Signalling route set unavailability . 5011.2.2 Signalling route set availability . 5011.2.3 Signalling route set congestion (International signalling network). 5011.2.4 Signalling route set congestion (National option withcongestion priorities)
29、. 5111.2.5 Signalling route set congestion (National options without congestionpriorities) . 5111.2.6 Signalling point/signalling transfer point congestion 5111.2.7 User Part availability control. 5111.2.8 User Part congestion 5212 Signalling link management . 5212.1 General 5212.2 Basic signalling
30、link management procedures 5412.2.1 Signalling link activation. 5412.2.2 Signalling link restoration . 5412.2.3 Signalling link deactivation. 5412.2.4 Link set activation 5412.3 Signalling link management procedures based on automatic allocation of signallingterminals 5512.3.1 Signalling link activa
31、tion. 5512.3.2 Signalling link restoration . 5612.3.3 Signalling link deactivation. 5712.3.4 Link set activation 5712.4 Signalling link management procedures based on automatic allocation of signallingdata links and signalling terminals 5812.4.1 Signalling link activation. 5812.4.2 Signalling link r
32、estoration . 5912.4.3 Signalling link deactivation. 6012.4.4 Link set activation 6012.5 Automatic allocation of signalling terminals 6112.6 Automatic allocation of signalling data links . 6112.7 Different signalling link management procedures at the two ends of a link set. 6313 Signalling route mana
33、gement . 6313.1 General 6313.2 Transfer-prohibited . 6313.3 Transfer-allowed. 6413.4 Transfer-restricted (National option) 6513.5 Signalling-route-set-test 66Recommendation Q.704 (07/96) viiPage13.6 Transfer-controlled (International network) . 6713.7 Transfer-controlled (National option with conges
34、tion priorities). 6713.8 Transfer-controlled (National option without congestion priorities) 6813.9 Signalling-route-set-congestion-test (National Option) 6814 Common characteristics of message signal unit formats 7014.1 General 7014.2 Service information octet 7014.2.1 Service indicator 7014.2.2 Su
35、b-service field 7114.3 Label . 7115 Formats and codes of signalling network management messages 7115.1 General 7115.2 Label . 7215.3 Heading code (H0) 7215.4 Changeover message. 7515.5 Changeback message 7515.6 Emergency changeover message. 7615.7 Transfer-prohibited message. 7615.8 Transfer-allowed
36、 message. 7715.9 Transfer-restricted message (national option). 7715.10 Signalling-route-set-test message . 7815.11 Management inhibit message 7815.12 Traffic restart allowed message 7915.13 Signalling-data-link-connection-order message . 7915.14 Signalling-data-link-connection-acknowledgement messa
37、ge. 8015.15 Transfer-controlled message. 8115.16 Signalling-route-set-congestion-test message (national option). 8115.17 User Part unavailable message 8216 State transition diagrams, abbreviations and timers . 8316.1 General 8316.2 Drafting conventions. 8316.2.5 Notations for national operations 841
38、6.3 Signalling message handling. 8416.4 Signalling traffic management 84viii Recommendation Q.704 (07/96)Page16.5 Signalling link management . 8516.6 Signalling route management . 8516.7 Abbreviations used in Figures 23 onwards. 8516.8 Timers and timer values 86Recommendation Q.704 (07/96) 1Recommen
39、dation Q.704SIGNALLING NETWORK FUNCTIONS AND MESSAGES(Geneva, 1980; modified at Helsinki, 1993; revised in 1996)1 Introduction1.1 General characteristics of the signalling network functions1.1.1 This Recommendation describes the functions and procedures for and relating to the transferof messages be
40、tween the signalling points, which are the nodes of the signalling network. Suchfunctions and procedures are performed by the Message Transfer Part at level 3, and therefore theyassume that the signalling points are connected by signalling links, incorporating the functionsdescribed in Recommendatio
41、ns Q.702 and Q.703. The signalling network functions must ensure areliable transfer of the signalling messages, according to the requirements specified inRecommendation Q.706, even in the case of the failure of signalling links and signalling transferpoints; therefore, they include the appropriate f
42、unctions and procedures necessary both to inform theremote parts of the signalling network of the consequences of a fault, and to appropriatelyreconfigure the routing of messages through the signalling network.1.1.2 According to these principles, the signalling network functions can be divided into
43、two basiccategories, namely: signalling message handling; and signalling network management.The signalling message handling functions are briefly summarized in 1.2, the signalling networkmanagement functions in 1.3. The functional interrelations between these functions are indicated inFigure 1.1.2 S
44、ignalling message handling1.2.1 The purpose of the signalling message handling functions is to ensure that the signallingmessages originated by a particular User Part at a signalling point (originating point) are delivered tothe same User Part at the destination point indicated by the sending User P
45、art.Depending on the particular circumstances, this delivery may be made through a signalling linkdirectly interconnecting the originating and destination points, or via one or more intermediatesignalling transfer points.1.2.2 The signalling message handling functions are based on the label containe
46、d in the messageswhich explicitly identifies the destination and originating points.The label part used for signalling message handling by the Message Transfer Part is called therouting label its characteristics are described in clause 2.1.2.3 As illustrated in Figure 1, the signalling message handl
47、ing functions are divided into: the message routing function, used at each signalling point to determine the outgoingsignalling link on which a message has to be sent towards its destination point; the message discrimination function, used at a signalling point to determine whether or not areceived
48、message is destined to the point itself. When the signalling point has the transfercapability and a message is not destined to it, that message has to be transferred to themessage routing function;2 Recommendation Q.704 (07/96) the message distribution function, used at each signalling point to deli
49、ver the receivedmessages (destined to the point itself) to the appropriate User Part.The characteristics of the message routing, discrimination and distribution functions are described inclause 2.T1158780-94/d001Level 4UserPartsLevel 3Message Transfer PartLevel 2MessageTransferPartSignalling network functionsMessagedistributionMessageroutingMessagediscriminationSignallingtrafficmanagementSignallingroutemanagementSignallinglinkmanagementSignalling network managementTesting and maintenance (Message Transfer Part)Signalling message flowIn
