CEPT T SF 34 E-1984 Customer Equipment Aspects of Terminal to Terminal Signalling《终端到终端信令的客户设备方面》.pdf

1、T/CF 34 E Page 1 Recommendation T/SF 34 E (Montpellier 1984) CONCERNING CUSTOMER EQUIPMENT ASPECTS OF TERMINAL TO TERMINAL SIGNALLING Recommendation proposed by Working Group T/WG 7 “Services and facilities” (SF) Text of the Recommendation adopted by Cominission “Telecommiciiicatioiis”: “The Europea

2、n Conference of Posts and Telecommunications Administrations, Considering 1. 2. That there is an emerging demand for subscribers to be able to signal from simple telephone terminals to other simple telephone terminals and also to other more sophisticated centres. That some applications that are emer

3、ging are: - for remote ordering of goods or services; - for remote control and checking of electrical equipment; - for remote interrogation of answering machines; - for text telephone using MFPB. That in general the emerging applications appear to have the following characteristics: - they generally

4、 require unidirectional transmission of signalhg information (note: a both-way “conversation” may be achieved by using, for example, normal speech information in one direction. Such an application is automatic services/goods ordering where guidance to customers who are placing the order can be provi

5、ded by means of synthesised speech); - terminal-to-terminal signalling is likely to require very low bit rates, typically estimated provisionally at less than 100 bit/s; - terminal-to-terminal signalling does not require any form of sophisticated automatic acknowledgement procedures ; - terminal-to-

6、terminal signalling does not require any form of error correction. That the charging arrangements for terminal-to-terminal signalling in an ISDN may be incompatible with those in traditional public telephone networks. For example charging arrangements in traditional telephone networks are generally

7、related to the time that a circuit is occupied, amongst other things. In an ISDN, Administrations may nd it expedient to raise charges for terminal-to-terminal signalling on the basis of the quantity of information transferred. That it is essential that the network can differentiate between terminal

8、-to-terminal signals and terminal-to- network signals. o 3. 4. 5. Recommends 1. That is should be a long-term aim of Administrations to offer a terminal-to-terminal signalling facility as part of the basic telephone service. It should be recognised that more sophisticated terminals would then be req

9、uired at the receiving end. That the facility should be available: - between any terminal connected to public telephone networks, - between extension terminals connected to PBXs which are themselves connected to public telephone networks - between extension terminals connected to PBXs and any termin

10、als connected to public telephone networks. That ideally the facility should be available from any terminal connected to public telephone networks, but it is recognised that some Administrations may wish to provide the facility by using special terminals. That terminal-to-terminal signalling should

11、ideally operate from any telephone. That an overriding requirement is that the service should be cheap. That in traditional public switched telephone networks the service should only be available after normal establisment of a successful (Le. one that is revenue-earning) call. That standardisation o

12、f the protocols to be used between terminals should not generally be the responsibility of Administrations although it is recognised that such standardisation is desirable. 2. and use the public telephone networks to convey the terminal-to-terminal signalling information, 3. 4. 5. 6. 7. O F Edition

13、of June 15, 1986 - _ - CEPT T/SF*34*E 84 232b414 0009344 T T/SF 34 E Page 2 8. 9. That terminal-to-terminal signalling should be provided in the ISDN. This requires further study but could possibly utilise the ?D? channel. That because the method of achieving terminal-to-terminal signalling in the I

14、SDN may be different from that used in traditional public telephone networks the same terminals may not operate on both networks, It should also be noted that Administrations may incur substantial costs if they wish to retain the same method of providing terminal-to-terminal signalling in an ISDN as

15、 used in traditional telephone networks. 10. That the charging arrangements for terminal-to-terminal signalling in an ISDN should as far as possible be compatible with those in traditional public telephone networks. 11. That the method of signalling between terminals should not interfere with signal

16、ling systems used by Administra- tions within their telecommunications networks. 12. That in any form of terminal-to-terminal signalling, register recall or a similar control procedure should be retained. 13. That for reasons of compatibility a code conversion may be required in the network in order to make this service available for different type of terminals in the same connection.? Edition of June 15, 1986