1、CEPT T/CS*49-05*E = 232b414 000490L 2 O Page 1 (3 TCS49-05 E Recommendation T/CS 49-05 (Vienna 1982, revised in Montpellier 1984) SYSTEM L1 MULTIFREQUENCY PUSH-BUTTON UNIDIRECTIONAL CALL CONTROL SIGNALLING PROCEDURES Recommendation proposed by Working Group T/WG 1 i “Switching and Signalling” (CS) R
2、evised text of the Recommendation adopted by the “Telecommunications ” Commission. “The European Conference of Postal and Telecommunications Administrations, considering - that multifrequency push-button (MFPB) subscribers line signalling may provide faster call Set-up than decadic - that equipment
3、located at subscribers premises and used in private networks more and more employs MFPB - that MFPB interregister signals as specified in Recommendation T/CS 49-04 i may be used either in the forward pulsing signalling, signalling techniques, direction only or in both the forward and the backward di
4、rection, recommends to the members that the call control signalling procedures specified below are used, when MFPB interregister signalling is applied in the forward direction only (unidirectional) between private automatic branch exchanges (PABXs), in different countries.” 1. GENERAL 1.1. Field of
5、application In the System L1 MFPB unidirectional call control signalling procedures, MFPB interregister signals are only used in the forward direction of call Set-up, e.g. the MFPB character set of the 12-button array according to Recommendation T/CS 46-02 2 is used for address signalling and servic
6、e control. The signalling procedures specified in this Recommendation cover the standard call Set-up and call clear-down. Enhancements providing the interchange of additional information are given as options, e.g. for recall and intrusion. 1.2. Signals On international leased lines, System L1 MFPB u
7、nidirectional, in accordance with Recommendation T/CS 49-04 i, is used in conjunction with System L1 line signalling as specified in Recommendation The signals actually used with System L1 MFPB call control procedures contained in this Recommendation are given in Table 1 (T/CS 49-05). The meanings o
8、f the signals comply with Recommendation T/CS 41-01 4. The requirements for the transmission of the signals are set-out in Recommendations T/CS 49-01 3, T/CS 49-02 5 and T/CS 49-04 i. The use of the address-complete signal and the answer signal is subject to options 2 and 3, respectively. The three
9、signals, address-complete, extension-free; address-complete, extension-busy and busy-extension- changed-to-free, may be chosen instead of the address-complete signal (option 4). If the signals intrusion and end-of-intrusion are used (option 5), then option 3 must be applied. The four recall signals
10、represent option 6. All options must be mutually agreed upon by the parties involved. Option 1 provides for the use of the seizing-acknowledgement signal instead of the proceed-to-send signal. T/CS 49-01 3. I. Edition of September 15, 1986 CEPT T/CS*49-05*E 2326434 0004402 4 = 1 TICS 49-05 E Page 2
11、I Signais Seizing Proceed-to-send Seizing-acknowledgement Address Clear-request Address-complete Answer Clear-forward Clear-back Cleared Address-complete, extension-free Address-complete, extension-busy Busy-extension-changed-to-free Intrusion End-of-intrusion Forward-service-request-recall Backward
12、-service-request-recall Backward-link-recall Proceed-to-send-on-recall Reconnect Option I Recommendation T/CS 49-01 T/CS 49-02 T/CS 49-01 T/CS 49-04 T/CS 49-01 TICS 49-02 T/CS 49-01 T/CS 49-01 T/CS 49-01 T/CS 49-01 T/CS 49-02 TICS 49-02 T/CS 49-02 T/CS 49-01 T/CS 49-01 T/CS 49-01 T/CS 49-01 T/CS 49-
13、01 T/CS 49-02 TICS 49-02 Legend: 1, 2, 3, 4, 5, 6: option I, 2, 3, 4, 5, 6. M: Mandatory. Table 1 (T/CS 49-05). Signals used in System LI MFPB unidirectional call control signalling. Note I; If option is provided, the seizing-acknowledgement procedure must be used instead of the proceed-to-send proc
14、edure. 2. SIGNALLING PROCEDURES 2.1. General 2.1.1. The signalling procedures are described by means of SDL diagrams in accordance with CCITT Recom- mendations 2.101 7, 2.102 8 and 2.104 9, and narrative comments. Table 4 in Recommendation T/CS 49-04 i includes abbreviations used in the SDL diagrams
15、. Note: The SDL diagrams are included in this Recommendation to assist in the understanding of the technical text and must only be used in association with the text. Where a service demand requires inter-PABX MFPB signalling, the request is handled by the responding PABX on an accept or reject basis
16、, depending upon the availability of the service at that PABX. 2.2. Set-up and clear-down of standard calls 2.2.1, Figures 1, 2 and 9 (T/CS 49-05) show the signalling sequences at the outgoing and incoming PABX line interfaces for Set-up and clear-down of standard calls. Following the proceed-to-sen
17、d signal, the register of the outgoing PABX sends the address signals. In the case of multi-link calls, the address signals are transferred link-by-link. The registers in the transit switches should preferably work in an overlap mode of operation. The selection phase is concluded by the address-comp
18、lete signal sent backwards from the destination PABX by address information analysis or internal time-out. The address-complete signal releases the registers in the terminating PABX and transit switches, initiates through-connection of the speech path and causes the transition to the end-ofselection
19、 state at the reference interfaces. In the end-of-selection state an additional signal interchange (e.g. covering options 3 or 3 and 4) may take place and cause transition to another state. For the SDL diagrams, this state is called post-dialling state. 2.3. Register-recall When option 5, register-r
20、ecall, is provided, Figures 3 to 6 (T/CS 49-05) apply. In the case of a service-request recall, no address-complete signal will be returned. Subsequently, the signalling process reverts to the appropriate post-dialling state. 2.4. Intrusion The procedure for intrusion requires the provision of optio
21、ns 3 and 4. Figures 7 and 8 (T/CS 49-05) apply. Edition of September 15, 1986 i O CEPT T/CS*49-05*E D 2326434 0004903 b D i (i) I I I-L - I TICS 49-05 E Page 3 (e) Figure 1 (T/CS 49-05). Call set-up (outgoing PABX). Edition of September 15, 1986 CEPT T/CS*49-05*E 2326414 0004904 8 T/CS 49-05 E Page
22、4 optlon 1 7 SPlZlrg I Awltlng dlglts i-) oatect rL Figure 2 (T/CS 49-05). Call Set-up (incoming PABX). I + I-(?-) Edition of September 15, 1986 CEPT T/CS*49-05*E W 2326434 0004905 T W Release TICS 49-05 E Page 5 Release gmd I PPXd to send M recall b I Aual t Ing arder to SKVj SWvlCe-reg- Info.dlglt
23、s Send dlglts ReleaSQ - Dlglts 1) Cld -1 SW I ce- Afta- cles-dovn at wtwlm PABX Cld reg-Info. Pre-dlalling M Il& recall Awltlrg orda- hlf0.M Il& Dlgl ts D I I cmplete 4 Post-dlal I Ing Edition of September 15, 1986 TICS 49-05 E Page 6 - Favsd Favad reg-recall SQWiCe- Ilk-recall T+) (-) (*) m Ilk rec
24、all o reg- fa &tu d detKtd caplete Post-dlall Irg (7) Figure 4 (T/CS 49-05). Forward register-recall (incoming PABX). O Edition of September 15, 1986 CEPT T/CS*49-05*E d W 2326414 0004907 3 ected TICS 49-05 E Page 7 Ilk-recall rep-recall I I I (+) i-) (-) repseCall req -recal I Valtlng for ServlCe4-
25、q- i Post-d I al I I w I nCM I ng Edition of September 15, 1986 Releass Cal I Cles- Clex- back fmd 1 Release Releas guard guard Figure 5 (T/CS 49-05). Backward register-recall (outgoing PABX). ifCC 49-05 E Page 8 CEPT T/CS*49-05*E 2326434 0004908 5 Fbstdlalllng (7) I I I R.ocppd to d cm recall Dlglt
26、s a q -Infa 7 piil m recall to d dlgl ts 1 coplete Fbstdlalllq (7) Olglts a Figure 6 (T/CS 49-05). Backward register-recall (incoming PABX). O Edition of September 15, 1986 CEPT T/CS*49-05*E = 232b414 0004909 7 I I Pmtdlal I Ing Intruslm Intruslm Intrusion 11- Pmt-dlall Ing (7) TICS 49-05 E Page 9 Q
27、 y) Release Figure 7 (T/CS 49-05). Options 4 and 5 (outgoing PABX). Edition of September 15, 1986 I CEPT T/CS*49-05*E D 232b414 0004LO 3 TICC 49-05 E Page 1 O r-I intruslm Q Post-diailing U Incning JI I (I O Edition of September 15, 1986 Figure 8 (T/CS 49-05). Options 4 and 5 (incoming PABX). CEPT T
28、/CS*49-05*E 2326434 0004911 5 T/CS 49-05 E Page 11 (-) 0 0 (-) incoming PABX IDLE IDLE Outgoing PABX Incoming PABX Figure 9 (T/CS 49-05). Call clear-down. 2.5. Clear-request on non-receipt of address information When after recognition of a seizing signal, no address or incomplete address or incomple
29、te information is received, the incoming PABX shall time-out and dissociate the inter-PABX circuit from any common equipment. Under these conditions the incoming PABX shall : (a) apply the clear-request signal, (b) bar access to the inter-PABX circuit for outgoing calls until a clear-forward signal
30、is recognized. Clear-request on encountering congestion or an engaged extension This procedure is optional. When an incoming PABX encounters congestion or an engaged extension, it may release the switching equipment, apply the clear-request signal and perform the procedures specified in 9 2.5. (b).
31、2.6. 2.7. Audible indications Provision must be made by the parties involved to ensure that the correct tones are returned to the caller when Sections 2.5. or 2.6. above apply. REFERENCES 11 Recommendation T/CS 49-04. System L1 multifrequency push-button interregister signalling. 2 Recommendation T/
32、CS 46-02. Multifrequency signalling system to be used for push-button telephones. 3 Recommendation T/CS 49-0 1. System LI line signalling over international inter-private automatic branch ex- change lines. 4 Recommendation T/CS 41 -01. Signal and signalling message names and meanings. 5 Recommendati
33、on T/CS 49-02. System LI decadic pulsing interregister signalling. 6 Recommendation T/CS 49-03. System L1 decadic pulsing signalling procedures. 7 CCITT Recommendation Z. 101. General explanation of the specijiication and description language (SDL 8 CCITT Recommendation Z. 102. Symbols and rules. 9 CCITT Recommendation Z. 104. Semantics. Edition of September 15, 1986
