1、CEPT T/CS*49-07*E m 2326414 0004941 3 TCS49-07 Page 1 Recommendation T/CS 49-07 (Vienna 1982, revised in Montpellier 1984) SYSTEM L1 MULTIFREQUENCY CODE INTERREGISTER SIGNALLING Recommendation proposed by Working Group T/WG 1 1 “Switching and Signalling (CS) Revised text of the Recommendation adopte
2、d by the “Telecommunications” Commission: “The European Conference of Postal and Telecommunications Administrations, considering Multifrequency Code (MFC) signalling may enable faster call Set-up than decadic pulse signalling; - that MFC signalling provides more codes than decadic pulse signalling;
3、- that MFC signalling employs in-band signals, and is thus suitable for use between private automatic branch - that MFC signalling is suitable for a dialogue-like interchange of signalling information; - that the compelled nature of MFC signalling provides a secure means of exchanging information, r
4、ecommends that members, in conditions favouring MFC signalling over links between analogue transmission interfaces of private automatic branch exchanges located in different countries, use System L1 MFC interregister signalling as specified below.” exchanges (PABXs) for end-to-end interregister sign
5、alling; 1. GENERAL 1.1. Line signalling System L1 MFC interregister signalling is used in conjunction with System L1 line signalling according to Recommendation T/CS 49-01 i. The individual line signals to be provided, and their use, are specified in Recommendation T/CS 49-08 2 on System L1 MFC call
6、 control signalling procedures. Principles and fields of application System LI MFC is suitable for automatic and semi-automatic working between private automatic branch exchanges (PABXs), via terrestrial circuits. When a satellite circuit is used in the connection, the echo- suppressor control princ
7、iples as described in Recommendation 4.479 101 are applicable. System L1 MFC can be used in private networks containing PABXs of different capability, which may range from the set-up of simple calls to a wide variety of supplementary services. System LI MFC is specified in terms of a standard select
8、ion procedure, followed by one of a number of alternative subsets of signalling procedures for transfer of additional information. The available subsets are: - simple calls only, called basic subset; - simple calls and access to supplementary services, called enhanced subset; - specific procedures d
9、efined by the PABX providers, called manufacturer subset. Signals have been reserved to provide access to an enhanced routing subset, which may be specified when necessary. The procedure subset used on a call after the standard selection procedure depends upon the capabilities of the interconnected
10、PABXs, and is determined by a compatibility check procedure. The specified signalling procedures include selection, compatibility checking and transfer of additional information (see Recom- mendation T/CS 49-08 2). A PABX, for which System L1 MFC is used, must be capable of providing at least the se
11、lection procedure, plus the basic subset of procedures for additional information transfer. This ensures a minimum level of interworking if compatibility using the optional enhanced or manufacturer subsets cannot be achieved. The system is for use on four-wire circuits, and the PABX termination arra
12、ngements setout in Recom- mendation T/CS 49-01 i apply. The maximum number of tandem connections over which a call may be setup is determined by the type of interconnecting circuits, and is subject to mutual akreement by the parties concerned. All circuits used in System L1 links should be to the st
13、andard of CCITT Recommendations G.171 3 and M.lO1O to M.1060 4. 1.2. 1.2.1. 1.2.2. 1.2.3. 1.2.4. 1.2.5. 1.2.6. O Edition of May 15, 1986 CEPT,T/CS*49-07*E 2326434 0004942 5 Name of signal Address, digit 1 Address, digit 2 Address, digit 3 Address, digit 4 Address, digit 5 Address, digit 7 Address, d
14、igit 8 Address, digit 9 Address, digit O Address, character j, Address, character # End-of-digits Change-over-to-en hunced-routing-subset Address, digit 6 Request-rejected T/CS 49-07 E Page 2 Abbrev. I- 1 I- 2 I- 3 I- 4 I- 5 I- 6 I- 7 I- 8 I- 9 1-10 1-1 1 1-14 1-15 1-13 1-12 INTERREGISTER SIGNALS Li
15、ne signalling frequency interregister signals In System L1 interregister signalling, a line frequency (2,280 Hz) backward signal is used for initiating MFC signal transfer, the proceed-to-send signal. This signai is introduced in accordance with Recommendation T/CS 41-01 5 and T/CS 49-02 6. MFC inte
16、rregister signals System L1 MFC is based on System R2, the multifrequency codes used are in accordance with CCITT Recommendation Q.441, Table 3/Q.441 7. When using the enhanced subset, the number of signal groups in each direction is extended. Forward signal groups are designated groups I, II, III,
17、etc., and backward signal groups A, B, C, etc. Tables 1 (T/CS 49-07) to 8 (T/CS 49-07) show the interregister signals specified in System L1 MFC. All signal names are in accordance with Recommendation T/CS 41-01 5. Frequency combination 1 2 3 4 5 6 7 8 9 10 11 14 15 13 12 Note Note I Note 2 Note 3 T
18、able 1 (T/CS 49-07). Group I forward signals. Note I: Signals used for selection. Note 2: Signals used to enable special actions during the selection phase. Note 3: Signal for subset compatibility check, e.g. for rejection of a munufcturer-request. O Edition of May 15, 1986 CEPT T/CS*49-07*E = 23264
19、34 0004943 i = TICS 49-07 E Page 3 Frequency combination Name of signal Abbrev. I Note 1 13 14 2 8 4 9 Send-next-digit Send-next-digit, PSTN-encountered Send-next-digit, transit-encountered Transit-encountered, send-first-digit Transit-encountered, alternatively-routed, send-first-digit Call-failure
20、 Routing-congestion A- 1 A-13 A-14 A- 2 A- 8 A- 4 A- 9 Note 1 5 10 12 Send-calling-partys-category Enhanced-routing, information-ready Enhanced-routing, no-information A- 5 A-IO A-12 Note 2 3 6 I 11 Address-complete, basic, change-over-to-groups-II-and-B Address-complete, no-MFC Change-over-to-manuf
21、acturer-subset Address-complete, request-manufacturer-identity Address-complete, enhanced, change-over-to-groups-II-and-B A- 3 A- 6 A- 7 A-1 1 Note 3 15 Spare A-I5 Table 2 (T/CS 49-07). Note 1; Signals used during the selection phase. Note 2: Signals used to enable special actions to be taken during
22、 the selection phase. Note 3: Signals used for the subset compatibility check. Group A backward signals. Frequency combination Name of signal Abbrev. Note II- 1 II- 2 II- 3 II- 4 II- 5 II- 6 II- 7 II- 8 II- 9 Ordinary-extension Private-circuit, restricted-signalling capability Maintenance-equipment
23、Public-switched-telephone-network (PSTN) Operator Data-transmission-equipment Operator-assisting, ordinary-extension Operator-assisting, PSTN Operator-assisting, restricted-signalling Network Ordinary-extension, holding-PSTN Extraordinary-extension ISDN Note 1 11-10 11-1 1 II- 13 11-14 10 11 13 14 N
24、ote 2 11-12 Note 3 12 Enhanced-subset-request-rejected 15 11-15 Spare Table 3 (T/CS 49-07). Group II forward signals. Note I: Signals used in both the basic and the enhanced subset. Note 2: These signals shall not be used in the basic subset. Note 3: Signal used for the subset compatibility check. E
25、dition of May 15, 1986 CEPT T/CS*49-07*E 2326434 0004744 7 Spare B-15 TICS 49-07 E Page 4 Frequency combination 1 2 3 4 5 6 I 8 9 10 I Name of signal Abbrev. B- 1 B- 2 B- 3 B- 4 B- 5 B- 6 B- I B- 8 B- 9 B-10 Note Note 1 Parked Call-failed, PSTN-barred Busy, intrudable Destination-PABX-call-failure U
26、nallocated-number, temporarily-out-of-service Free, intrudable Free, non-intrudable Call-failed, incoming-call-barred Destination-PABX-congestion Busy, non-intrudable 11 12 13 14 Free, operator Busy, partially-intrudable Free, partially-intrudable State-of-destination-indeterminable B-11 B-12 B-13 B
27、-14 Note 2 15 Table 4 (T/CS 49-07). Group B backward signals. Note 1: Signals used in both the basic and enhanced subset. Note 2: These signals shall not be used in the basic subset. Frequency combination Name of signal Abbrev. Note 1 2 3 4 9 10 15 Simple call Simple call, diverted Simple call, non-
28、intrudable Simple call, diverted, non-intrudable Simple call, partially-intrudable Simple call, diverted, partially-intrudable No-further-supplementary-services-required III- 1 III- 2 III- 3 III- 4 III- 9 111-10 111-15 Note 1 5 6 I 8 11 12 Supplementary-service Supplementary-service, diverted Supple
29、mentary-service, non-intrudable Supplementary-service, diverted, non-intrudable Supplementary-service, partially-intrudable Supplementary-service, diverted, partially-intrudable III- 5 III- 6 III- I III- 8 111-1 1 111-12 Note 2 13 14 Spare Spare 111-13 111-14 Table 5 (T/CS 49-07). Group III forward
30、signals. Note I: These signals indicate that the originating PABX has no further need for MFC signalling. Note 2: These signals indicate that the originating PABX wishes to request a forward supplementary service, and that further MFC signalling is required beyond this group. Edition of May 15, 1986
31、 CEPT T/CS*49-07*E 232b414 0004945 O Supplementary-service, non-intrusion-request-rejected Supplementary-service Supplementary-servie, PSTN-barred Supplementary-service, PSTN-barred, non-intrusion-request-rejected Send-calling-line identity (CLI) Send-CLI, PSTN-barred Send-CLI, non-intrusion-request
32、-rejected Send-CLI, PSTN-barred, non-intrusion-request-rejected Request-forward-supplementary-service category Spare c- 7 c- 8 c-IO C- 13 c- 9 c-11 c-12 C-14 C-15 C- 6 Recommendation T,CS 49-08 21 or manufacturer Request-rejected, no-further-MFC-required Request-backw. suppl.-service- category Reque
33、st-back- ward-suppl.- service-identity , Note I Spare T/CS 49-07 E Page 5 Note Note I Note 2 Name of signal I Abbrev. Frequency combination 1 2 3 4 5 7 8 IO 13 9 11 12 14 15 6 Conclude-MFC, no-additional-information Conclude-MFC, PSTN barred Conclude-MFC, no-additional-information, non-intrusion- re
34、quest-rejected Call-failure Conclude-MFC c- 1 c- 2 c- 3 c- 4 c- 5 Table 6 (T/CS 49-07). Group C backward signals. Note 1: These signals conclude MFC signalling and return control of the call to System LI line signals. Note 2: These signals cause change-over to groups IV and D signalling. _ Previous
35、backward signal which determines the grou VI signal meaning Request for- ward-suppl.- service cate- gory, C-15 or register recall Forward servicc category digit Request for- ward-suppl.- service iden- tity, D-15, Note I Suppl. service identity digit Backward service cate- gory, D-1 suppl.- to D-15 S
36、pare (Note 3) Must not be sent in -esponse to the escape signal D-10 Backward suppl.- service-iden- tity digit, D-l to D-15 Signals provided for suppl. ser- rice procedures, see Note 2 3K, no-further MFC-required Send-CLI, C-9, C-11, C-12 or C-14 or send- next-CLI-digit, CLI-digit 1 2 3 4 5 6 7 8 9
37、10 CLI-digit j, D-15 Suppl.-service signal, C-7, C-8, C-IO or C-13 Invalid Frequency combina- tion Note I : Request-suppl.-service-identity signal equals send-next-supp1.-service-identity-digit signal, see Recommendation TICS 41-01 151. 10 11 Note 2: See Annexes to 12 Invalid Invalid 13 documentatio
38、n. OK, no-further I Invalid I pare (Note 3, I MFC-possible 14 CLI-digit # I Request-rejected, further-MFC-possible End-of- digits 15 Table 7 (T/CS 49-07). Group IV forward signals. Edition of May 15, 1986 CEPT T/CS*49-07*E 232b4it4 000494b 2 Request-back- ward-supp1.- service-cat- egory IV- 15 TJCS
39、49-07 E Page 6 Request-back ward-suppl. service-iden- tity IV- 15 Frequency combina- tion for suppl. service proce- dures, see Note 2 10 Supp1.-service- Supp1.-service category digit identity digit Note 1: Request-suppi.-service- identity signal equals send-next- 11 Request-for- ward-supp1.- service
40、 12 Spare 13 14 15 Supp1.-service category IV-1 to 15 Previous forward signal which determines the grou Spare (Note 3) Can never be sent in response to escape signal IV-10 Supp1.- service identity-digit IV-1 to 15 I Signals provided Note I .- supp1.-service-digit signal, see Recommendation T/CS 41-0
41、1 5 I Escape OK, conclude MFC -1 Note 2: See Annexes to Request-rejected, Recommendation conclude MFC I T/CS 49-08 2 or -1 manufacturer documentation. OK, change- I III-and-C I pare over-to-groups- (Note 3) D signal meanii CLI-digit, IV-1 to 10 or end-of-digits, IV- 15 Invalid OK, conclude MFC Inval
42、id OK, change- over-to-groups- III-and-C Invalid Send-next- CLI-digit OK or request- rejected, IV-1 1, IV- 12, IV- 13, IV-14 Invalid Accept- acknowledged conclude MFC Reject- acknowledged, conclude MFC Accept-ac- knowl., change- over-to-groups- III-and-C Reject-ac- knowl., change- over-to-groups- II
43、I-and-C Invalid Table 8 (T/CS 49-07). Group D backward signals. 3. SYSTEM L1 MFC SIGNALLING GROUP STRUCTURE The signals are allocated to the 15 MFC codes in five forward and five backward signal groups. The signal group represented by the MFC codes is changed at defined points in the call; the same
44、MFC code will therefore represent a different signal, depending on its position in the sequence of the call. Each signal group is used for a particular part of the call. - Groups I and A are used for selection, network control and subset compatibility checks. - Groups II and B are used to exchange c
45、alling and called party information. - Groups I and A, plus part of groups II and B, provide the necessary signals for establishing a simple - The remaining groups II and B signals, and the groups beyond, are only provided when enhanced - Groups III and C are provided to exchange additional calling
46、and called party information, and to gain - Groups IV and D are provided to convey supplementary service request information and provide - Groups V and E are for the enhanced routing subset. The enhanced routing subset is still under study. call using the basic subset for the transfer of additional
47、information. procedures for the transfer of additional information are used. access to the supplementary services request procedures. calling-line-identification. Edition of May 15, 1986 CEPT T/CS*49-07*E 2326434 0004947 4 4. 5. 5.1. 5.2. 5.3. 5.4. 5.5. 5.6. 5.7. 6. TICS 49-07 E Page 7 PULSED SIGNAL
48、LING A pulsed signal is a signal sent in the backward direction for the period specified in CCITT Recommenda- tion 4.422 6. Signals assigned for use in the pulsed mode are backward signals A-4, A-6, A-9, B-4, B-9, C-4, and D-12, see Tables 2 (T/CS 49-07), 4 (T/CS 49-07), 6 (T/CS 49-07) and 8 (T/CS 4
49、9-07). A pulsed signal may be sent when either of the following conditions arise: 1. when the time-out on non-receipt of a signal matures before the first forward signal is received; 2. following completion of a compelled signalling cycle, if no subsequent forward signal has been recog- nised, and at least 100 ms have elapsed since the end of transmission of a backward signal. The initiating PABX shall terminate any forward signal in the course of transmission, on receipt of a pulsed signal. It is desirable that reception of a forward signa
