1、INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.764 Amendment I (07/2001) SERIES Q: SWITCHING AND SIGNALLING Specifications of Signalling System No. 7 - ISDN user part Signalling system No. 7 - ISDN user part signalling procedures Amendment I ITU-T Recom
2、mendation Q.764 - Amendment 1 (Formerly CCITT Recommendation) ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING Signalling System No. 7 management 1 Transaction capabilities application part SIGNALLING IN THE I“ATI0NAL MANUAL SERVICE FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN SPE
3、CIFICATIONS OF SIGNALLING SYSTEMS No. 4 AND No. 5 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 SPECIFICATIONS OF SIGNALLING SYSTEM R1 SPECIFICATIONS OF SIGNALLING SYSTEM R2 DIGITAL EXCHANGES INTERWORKING OF SIGNALLING SYSTEMS SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 INTERNATIONAL AUTOMATIC AND SEMI-AU
4、TOMATIC WORKING CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS General Message transfer part (h.ITp) Signalling connection control part (SCCP) Telephone user part (TUF) ISDN supplementary services Data user part Test specification 43 INTERFACE DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 PUBLIC LAND MOB
5、ILE NETWORK INTERWORKING WITH SATELLITE MOBILE SYSTEMS INTELLIGENT NETWORK SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IPIITT-2000 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) BROADBAND ISDN 4.1-4.3 4.4-4.59 4.60-4.99 Q.lOO-Q.119 Q. 120-Q.249 Q.25O-Q.309 4.3 10-4.399
6、4.400-4.499 Q.500-Q.599 4.600-4.699 Q.70O-Q.799 4.700 4.701-4.709 Q.711-Q.719 4.720-4.729 4.730-4.739 4.7404.749 4.750-Q.759 4.770-4.779 4.780-4.799 Q.SOO-Q.849 Q.850-Q.999 Q.1000-Q.1099 Q. 1100-Q. 1199 Q. 1200-Q. 1699 Q. 1700-Q. 1799 Q. 1900-Q. 1999 Q.2000-Q.2999 For or, as a national option the ci
7、rcuits in the idte state remain locally blocked. and a non-call controt message rewiring a resnonse shall be sent to the distant ISUP. On receipt of the response message (or any other signalling message) from the distant ISW. the local blocking resulting irom the previouslv received MTP pause primit
8、ive shall be removed. Normal call release procedures that may have started during the period of signalling isolation continue and as such will ensure that affected circuits are returned to the idle state. - 3) Add the following: 2.21 New clauses 2.21 to 2.25 Signalling procedure for tandem mode oper
9、ation of Digital Multiplexing Equipment with Low-bit-rate Voice CODEC ME with LVC) 2.21.1 Introduction In order that Digital Multiplexing Equipment with Low-bit-rate Voice CODEC ME with LVC) can operate in tandem mode without unnecessary decompression and recompression of voice, by means of 1) 2) th
10、e tandem mode operation signalling procedures are used on a per-call basis to convey information between the exchanges about the voice compression type(s) used in the preceding network for the call, whether voice is compressed between the exchanges and the voice compression status (if voice is compr
11、essed). routing of calls to appropriate circuits witldwithout DMEk with LVC; and enablingdisabling of voice decompressionhecompression in DMEs with LVC, ITU-T Q.764/Amd.l(07/2001) 1 2.21.2 Signalling procedures 2.21.2.1 Actions at originating exchange When the originating exchange receives a call fr
12、om the calling user, based on the information of the received call control message and/or the system configuration of the exchange, the exchange analyzes whether the outgoing circuit including DME with LVC can be selected. If the originating exchange judges that the outgoing circuit including DME wi
13、th LVC can not be selected, the originating exchange routes the call to the outgoing circuit without DME with LVC. If the originating exchange judges that the outgoing circuit including DME with LVC can be selected, the exchange: - - - routes the call to the outgoing circuit including DME with LVC;
14、enables compression of voice in the DME with LVC over the outgoing circuit; adds Type of voice compression and Compression status of Coding Decoding Processing Parameter (CDP-P) in IAM message which are set as the used voice compression type and “Compressed“ regarding the used voice compression type
15、; and sets the used voice compression type into User information layer 1 protocol of User Service Information Parameter (USI-P) in IAM message regarding the used voice compression type. - 2.21.2.2 Actions at intermediate exchange When the intermediate exchange receives a call, based on the informati
16、on of the received call control message and/or the system configuration of the exchange, the intemediate exchange judges the configuration case of DME with LVC from the following four cases: - Case 1 The DMEs with LVC with the same type of voice compression capability are used over the incoming circ
17、uit and the outgoing circuit. The DMEs with LVC is included in the circuit on the incoming side and the DME with LVC is not included in the circuit on the outgoing side. - Case 2 - Case 3 The DME with LVC is included in the circuit on the outgoing side and the DME with LVC is not included in the cir
18、cuit on the incoming side. The DME with LVC with the different types of voice compression capability are used over the incoming circuit and the outgoing circuit. - Case 4 2.21.2.2.1 The intermediate exchange: - Actions at intermediate exchange for Case 1 disables decompression of voice in the DME wi
19、th LVC over the incoming circuit and recompression of voice in the DME with LVC over the outgoing circuit; sets the used voice compression type and “Compressed“ into Type of voice compression and Compression status of Coding Decoding Processing Parameter (CDP-P) in IAM message which are same as thos
20、e of the received call control message; and sets the used voice compression type into User information layer 1 protocol of User Service Information Parameter (USI-P) in IAM message which are same as those of the received call control message. - - 2 ITU-T Q.764/Amd.l(07/2001) 2.21.2.2.2 Actions at in
21、termediate exchange for Case 2 The intermediate exchange: - - enables decompression of voice in DME with LVC over the incoming circuit; sets “Decompressed“ into Compression status of Coding Decoding Processing Parameter (CDP-P) in IAM message regarding the used voice compression type; and sets “p-la
22、w/A-law“ into User information layer 1 protocol of User Service Information Parameter (USI-P) in IAM message. - 2.21.2.2.3 Actions at intermediate exchange for Case 3 When the intermediate exchange receives a call, based on the received call control message, the intermediate exchange analyzes whethe
23、r the new voice compression causes severe voice quality degradation. If the intermediate exchange judges that severe voice quality degradation is caused, the intermediate exchange routes the call to the outgoing circuit without DME with LVC. If the intermediate exchange judges that severe voice qual
24、ity degradation is not caused, the intermediate exchange: - - enables compression of voice in the DME with LVC over the outgoing circuit; adds Type of voice compression and Compression status of Coding Decoding Processing Parameter (CDP-P) in IAM message which are set as the used voice compression t
25、ype and “Compressed“ regarding the used voice compression type; and sets the used voice compression type into User information layer 1 protocol of User Service Information Parameter (USI-P) in IAM message regarding the used voice compression type. - 2.21.2.2.4 Actions at intermediate exchange for Ca
26、se 4 When the intermediate exchange receives a call, based on the received call control message, the intermediate exchange analyzes whether the new voice compression causes severe voice quality degradation. If the intermediate exchange judges that severe voice quality degradation is caused, the inte
27、rmediate exchange routes the call to the outgoing circuit without DME with LVC. If the intermediate exchange judges that severe voice quality degradation is not caused, the intermediate exchange: - enables decompression of voice in the DME with LVC over the incoming circuit and compression of voice
28、in the DME with LVC over the outgoing circuit; sets “Decompressed“ into Compression status of Coding Decoding Processing Parameter (CDP-P) in IAM message regarding the used voice compression type; adds Type of voice compression and Compression status of Coding Decoding Processing Parameter (CDP-P) i
29、n IAM message which are set as the used voice compression type and “Compressed“ regarding the used voice compression type; and sets the used voice compression type into User information layer 1 protocol of User Service Information Parameter (USI-P) in IAM message regarding the used voice compression
30、 type. - - - 2.21.2.3 Actions at destination exchange When the destination exchange receives, based on the information of the received call control message, the destination exchange analyzes whether the call is received via the incoming circuit including DME with LVC. ITU-T Q.764/Amd.l(07/2001) 3 If
31、 the destination exchange judges that the call is received via the incoming circuit including DME with, the destination exchange: - It is for further study whether the information included in Coding Decoding Processing Parameter (CDP-P) is sent to the called party in the case of a subscriber with di
32、gital access. 2.22 Unless a bilateral or multilateral agreement is reached among the network operators concerned, messages, parameters and parameter values marked as “national use“ are not valid in the international network. Thus, an outgoing or incoming international gateway shall ensure that any “
33、national use“ messages/parameters/values received fi-om its associated national network are not passed on. NOTE - This requirement can be satisfied, for example, by the international gateway: - - 2.23 Inter-nodal traffic group identification The Inter-nodal Traffic Group Identifier parameter may be
34、included in the IAM in order to enable classification of calls between adjacent nodes. It identifies the logical traffic group to which the call belongs; i.e. this identifier is of significance only between two adjacent nodes. These classifications could, for example, be used to make a distinction b
35、etween different service sets. These classifications are not standardized. enables decompression of voice in DME with LVC over the incoming circuit. Handihg of national use elements at an international gateway exchange fully implementing the appropriate national procedures, and any necessary interwo
36、rking functions; or treating all “national use“ codespace as unrecognized, and providing “pass-on not possible“ treatment. 2.23.1 Sending Inter-nodal traffic group identification If needed for the chosen outgoing route, the exchange shall include the Inter-nodal Traffic Group Identifier parameter, p
37、opulated according to the relevant classification. This classification may depend on a classification received on the incoming side. NOTE - The Parameter Compatibility Instruction Indicators for this parameter should be set to mure that the parameter is not passed on at a node that does not recogniz
38、e the parameter. 2.23.2 Receiving Inter-nodal traffic group identification The traffic group identification received in a Inter-nodal Traffic Group Identifier parameter is used according to the relevant classification. A received Traffic Group Identifier parameter may be used to infiuence the routin
39、g of the call. 2.24 Carrier selection information (national use) 2.24.1 Action required at the originating exchange If a Carrier Selection is invoked by the user (reception of carrier selection information fi-om the access) or by the network operator, the exchange shall send the Carrier Selection In
40、formation (CSI) parameter in the IAM. NOTE - The carrier selection information received Com the access can be provided by a short prefx conveyed in the calied party number or by other means, depending on the access signalling system. The CSI parameter shall be set as follows: If call-per-call Carrie
41、r Selection is not invoked and there is a preselected carrier, then the CSI parameter is set to “selected carrier identification pre-subscribed, and no input by calling party“ (value 1). input of callingparty“ (value 10) (see Note below). a If a carrier is call-per-call selected, then the CSI parame
42、ter is set to Tarrier selected by 4 ITU-T Q.764/Amd.l(07/2001) If a carrier is selected by the network operator to which belongs the exchange, then the CSI parameter is set to %arrier selected by a network operator” (value 1 1). If no Carrier Selection is invoked, the CSI parameter shall not be sent
43、. NOTE - A coding giving more accurate information could possibly be used (“Selected Carrier identification pre-subscribed and input by calling party” (value 2) or “Selected Carrier identffcation not pre-subscribed, and input by calling party” (value 4). The reason for using a generic coding (value
44、1 O) comes from regulation in some countries which protects privacy of the calling party. 2.24.2 Action required at an intermediate exchange within the originating network The intermediate exchange shall pass unchanged the CSI parameter to the subsequent exchange. 2.24.3 Action required at an outgoi
45、ng national gateway exchange The outgoing national gateway exchange will pass on the parameter transparently. 2.24.4 Action required at an incoming national gateway exchange a) In case the network to which belongs the gateway exchange is explicitly selected: The handling of the content of the CSI pa
46、rameter is a network matter. However, the parameter shall not be sent to any subsequent network. In case the network to which belongs the gateway exchange is not explicitly selected: The call is routed through the network with the CSI parameter unchanged. 2.24.5 Action required at the destination ex
47、change No special action required. 2.24.6 Action required at an international gateway exchange The international gateway exchange shall discard the CSI parameter. 2.25 Global Cali Reference The Global Call Reference parameter is generated by the first exchange in a call path that requires a globally
48、 unique call reference to be associated with a particular call. The Global Call Reference is a combination of a Network ID field, a Node ID field and a Call Reference ID field. The Network ID field will uniquely identi the network; the Node ID field will uniquely identify the node within this networ
49、k that generates the Global Call Reference parameter. The Call Reference ID field will be a unique number generated on a per-call instance within this node. The Global Call Reference parameter is sent in the forward direction in the IAM. The intermediate exchange shall pass this parameter unchanged. The Global Call Reference parameter shall be stored in the nodes which require this reference according to the needs of the application that uses the information. NOTE 1 - The Global Call Reference parameter may typically be used for off-line purposes (e.g. to be stored for billing applic
