1、- CCITT RECMN*E*33L 91 4862573 0560550 T NTERNATIONAL TELECOMMUNICAT CCITT ON UNION TH E INTERNATIONAL TELEGRAPH AND TELEPHONE CONS U LTATIVE COM M ITTE E TELEPHONE NETWORK AND ISDN OPERATION, NUMBERING, ROUTING AND MOBILE SERVICE E.331 MINIMUM USER-TERMINAL INTERFACE FOR A HUMAN USER ENTERING ADDRE
2、SS INFORMATION INTO AN ISDN TERMINAL Recommendation E.331 I Geneva, 1991 CCITT RECMN*E.*333 91 4862593 0560553 I INTERNATIONAL TELECOMMUNICATION UNION CCITT E.331 THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE TELEPHONE NETWORK AND ISDN OPERATION, NUMBERING, ROUTING AND MOBILE SERV
3、ICE l MINIMUM USER-TERMINAL INTERFACE FOR A HUMAN USER ENTERING ADDRESS INFORMATION INTO AN ISDN TERMINAL Recommendation E331 I Geneva, 1991 -_ _ CCITT RECMN*E*33L 91 48b259L 0560552 3 - FOREWORD The CCIT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the
4、Intemational Telecommunication Union (ITU). CCIIT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The Plenary Assembly of CCITT which meets every four years, establishes th
5、e topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCI” between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). Recommendation E.331 was prepared by Study Group I and wa
6、s approved under the Resolution No. 2 procedure on the 11th of October 1991. CCIT NOTES 1) telecommunication Administration and a recognized private operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a 2) A list of abbreviations used in
7、 this Recommendation can be found in Annex A. O IT 1991 All 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. CCITT RECMN*E.*33L 91 = 48b2
8、591 05b0553 5 Recommendation E.331 MINIMUM USER-TERMINAL INTERFACE FOR A HUMAN USER ENTERING ADDRESS INFORMATION INTO AN ISDN TERMINAL 1 General 1.1 Intent This Recommendation is intended to achieve a degree of world-wide uniformity in the basic procedure for a human user inputting address informati
9、on such as destination numbers to an ISDN terminal. It is desirable for a user employing these basic procedures to be able to establish an ISDN connection using any ISDN terminal without requiring specific knowledge about the characteristics of that terminai. It is intended to cover the long-term re
10、quirements rather than to meet intermediate, change-over needs, It provides for the same procedure for the two kinds of signalling: functional (en bloc) signalling between the terminal and the network, and stimulus (overlap) signalling between the user and the network (as in the PSTN). 1.2 Backgroun
11、d The customer using a PSTN terminal communicates directly with a network, but a customer using an ISDN terminal with functional signalling communicates by means of the terminal, which delivers appropriate access- signalling messages to a network in a different form from that used between the user a
12、nd the terminal (see Figure 1E.331). ! User-terminal ! interface *. II I User Terminai Network m Dialling plan Numbering plan T0201080-87 FIGURE 1E.331 The relationship of dialling plan and numbering plan when functional signalling is used There are many ways by which users could interact with termi
13、nals to make their intentions known; they will, The minimum procedures specified here are suitable for use with a terminal having ten digits, a star (*) and a in practice, vary according to features provided and to cost. square (#) available for input dialling l). “Dialling“ normallly means signalhg
14、 directly to a switch with a rotary or pushbutton dial. The word “dialling“ in this Recommendation is used to mean either this or pushing the diai-pad buttons of a terminal to instruct that terminal. In this Recommendation, references to parameters like NPI and TON, that in Recommendation 4.931 refe
15、r to machine-read fields, refer here to the digits input to the terminais from which the appropriate 4.931 information is derived. Recommendation E.331 1 _- CCITT RECMN*Em*33L 71 4862593 05b0554 7 m Minimum procedural requirements are in no way intended to preclude taking advantage of opportunities
16、for new or varied communication services, or the design of intelligent terminals, or the design of cooperative procedures for user control. They are intended to ailow the establishment of connections without regard to the type of terminal, and to achieve as much similarity as possible between differ
17、ent countries of origination. Application is primarily but not exclusively aimed at terminals supporting single services, usualiy voice services. 1.3 Underlying principles Some aspects of the ISDN, notably the openness of the numbering plan, the possibility for sub-addresses, and the existence of fu
18、nctional signalling may require users to do some things in ways different from how they are done in the PSTN. However, it is possible and desirable to preserve some aspects of using the PSTN, and this Recommendation attempts to do this as it aims at the following goals: unifying the minimum user-ter
19、minal interface procedures world-wide for establishing calls from ISDN terminals; requiring nothing more of the terminal than the equivalent of the 12-button telephone pad; assisting in a smooth transition from PSTN to ISDN by preserving where possible and convenient a similarity to the procedures o
20、f the PSTN, in particular, by allowing a user to set up a simple voice call with a procedure daering as little as possible from that used for the same purpose in the PSTN, and by maintaining a positioning analogy between the information associated with a destination number and the national uses of p
21、refixes in the PSTN, having procedures bear a visible relationship to the numbering plan for the ISDN era (see Recommendation E. 164); minimizing the number of control actions needed and making it reasonably easy to remember what to do; having the same procedures for functional signalling (where the
22、 terminal translates into Q.931 protocols) as for stimulus signalling (where the network makes the translation). In specifying the basic procedure, this Recommendation recognizes that an agreed set of principles does not necessarily lead different people to the same solution, even though one of the
23、principles is that a single solution is desirable. This Recommendation embodies these principles and provides a single solution 2 Minimum terminal capability 2.1 receive as input from the human user the ten decimal digits and the star (*) and the square (#). This Recommendation defines a minimum pro
24、cedure that can be applied to a termina. -aving the ability to 2.2 The minimum procedure enables the user to specify, for an intended connection: a) the destination number; b) the destination sub-address, if any; c) the numbering plan identification (NPI), if necessary; d) the type of number (TON),
25、if necessary. Future study should add to this list the method to select a carrier and the method to access a supplementary service. 2.3 The minimum procedure does not provide for user input of data for every field required in Q.931 for ISDN addressing. Default values for some fields must be assigned
26、 by the terminal in the case of functional signalling, or by the network in the case of stimulus signalling. 2 Recommendation E.331 CCITT RECMN*E.*331 91 W 4862593 0560555 9 m 3 Numbering plan identification (“I) 2, 3.1 If the called number is in the same numbering plan as the default numbering plan
27、 of the originating terminal, no NPI need be indicated by the user. Note - A voice terminal connected at an S reference point behind a PABX would normally have the private numbering plan of the PABX as its default. A voice terminal connected to the public network via a coincident S/T reference point
28、 would have the E.164 numbering plan as its default. Except when the originating terminal is behind a PABX, the need to indicate a different numbering plan may be infrequent. 3.2 The NPI should be indicated, if at ali, by a single digit followed by a star (*). The digits to be used are for further s
29、tudy. This provision applies only to terminals connected to the public network via a coincident S/T reference point. It is desirable, but not required, that tefminals connected at an S reference point behind a PABX also follow this provision. 3.3 The NPI, when input, precedes both the TON and the ca
30、lled number. Note - A separator is used after the NPI to avoid reserving a digit that could not be used to start an E. 164E. 163 number. 4 Type of number (TON) 3, 4.1 The type of number (TON) should be indicated, if necessary, by up to three digits. To prevent user confusion due to conflict with exi
31、sting national procedures (e.g. prefmes for international access, toll calls and trunk calls), the assignment of TON is a national matter. Note I - Since no character is used to delimit the TON, it should start with a digit that is not used to start a national E.164 number. Note 2 - It is anticipate
32、d that Administrations will choose to indicate TONS for the international number, national number, and network-specific number with the same digits that are used as prefures for analogous purposes in their PSTNs. 4.2 4.3 5 5.1 5.2 5.3 5.4 5.5 The absence of a TON should be taken to mean a local subs
33、criber number. The indication of TON should follow the NPI (if any) and precede the called number. Sub-address and end of dialling The start of a dialled sub-address is indicated by a star. The end of a dialled address (including sub-address, if any: see Figure 2B.33 1) is indicated by a square. Not
34、e - The square is recommended as an end-of-message character in Recommendation E.132. The sub-address of a terminal intended to be accessible from simple terminals should c_ontain only digits. If dialling stops without the terminating square, the decision on how to respond is a national matter. For
35、networks that implement fixed length addresses, it is a matter for urgent study to determine whether an alternative procedure can be defined that does not require a terminator or time-out on every caii, including those that do not involve sub-addresses. 2, Numbering plan identification (NPI) was for
36、merly known in the CCIT Red Book as numberingladdressing plan Information (NAPI). 3, Type of number (TON) was formerly known in the Re Book as type of address (TOA). Recommendation E.331 3 CCITT RECMN*E*331 91 W 4862591 0560.556 O 4 b For example: Note - Because of the possible input of a sub-addres
37、s, a terminal cannot determine from numbering plan information alone (e.g. fixed length numbers) that input has ended. 6 Carrier selection Where pre-cail carrier selection is offered, it is desirable that the basic procedure provide a method for the user to make this selection. This is a matter for
38、future study. 7 Summary 7.1 The NPI followed by a star should be dialled first, ifnecessary. 7.2 The type of number should be dialled next, if necessary. 7.3 The address number should be input next, including one star to begin a sub-address if present, and ending with the terminator square. 7.4 The
39、general sequence is illustrated in Figure 2B.331, with examples of phcular sequences in Figures 3E.331 to 6E.331. In these figures, a national destination code (NDC) in an ISDN number is analogous to a trunk code or area code in a PSTN number. 7.5 A method for selecting a carrier is for future study
40、, as is the method to access a supplementary service. Structure “Dialling“ sequence NPI * TON Always signalieda) ISDN address 4 I cc NDC SN * SA Not always signalled w w # w T0101720-91 CC Country code NDC National destination cade NPI Numbering pian identification SA Sub-address SN Subscriber numbe
41、r TON Type of number a) For the terminating #, “always signalled“ means either that the # is signalled, or that the termination of dialling is deduced by a terminal or switch, This interpretation is applicable to the # throughout Figures 2B.331 to 6B.331. Note -It would be seldom, if ever, that ever
42、y part of this sequence were input for a single connection. 4 FIGURE 2E.331 General sequence, illustrated with an ISDN number Recommendation E.331 CCITT RECMN*E*331 91 4Bb2.591 0560557 2 = Address from the data numbering plan 4 b Input sequence NP * Number # TO101730-91 FIGURE 3E.331 Calling a numbe
43、r in the data numbering plan (Recommendation X.121) Structure Input sequence o SN #I TO101690-91 FIGURE 4E.331 Calling a local ISDN number without a sub-address sequence TON NDC SN # TlXO17-91 FIGURE 5B.331 Calling a long-distance national PSTN number Recmmendation E.331 5 cc NDC NPI SA SN TON 6 CCI
44、TT RECMN*E-*331 71 LI8b257L 0560558 4 Input sequence TON cc NDC SN * SA # TO1 O1 7 10-91 FIGURE 6E.331 Calling an international ISDN number with a sub-address ANNEX A (to Recommendation E.331) Alphabetical list of abbreviations used in this Recommendation Country code National destination code Numbering plan identification Sub-address Subscriber number Type of number Recommendation E.331
