1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 % TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%0(/.%G0G0.%47/2+G0G0!.$G0G0)3$./0%2!4)/. G0G0.5-“%2). G0G02/54).!.$G0G0-/“),%G0G03%26)#%).$)#!4)/.3G0G04/G0G053%23G0G0/&G0G0)3$.4%2-).!,3)45G134G0G0RecommendationG0G0% (Extract from the “LUEG0“OOK)NOTES1
2、ITU-T Recommendation E.184 was published in Fascicle II.2 of the Blue Book. This file is an extract from theBlue Book. While the presentation and layout of the text might be slightly different from the Blue Book version, thecontents of the file are identical to the Blue Book version and copyright co
3、nditions remain unchanged (see below).2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both atelecommunication administration and a recognized operating agency. ITU 1988, 1993All rights reserved. No part of this publication may be reproduced or utilized i
4、n any form or by any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the ITU.Fascicle II.2 - Rec. E.184 1Recommendation E.184Fascicle II.2 - Rec. E.184INDICATIONS TO USERS OF ISDN TERMINALS1 Introduction1.1 Recommendations E.180 to E.184 deal
5、with tones and other indications to users of the telephone service.This Recommendation covers the related but perhaps different requirements of the ISDN.1.2 A persons ability to learn, distinguish between, and remember different tones representing abstract conditionsis limited (to about four to six
6、tones). Users are frequently confused by unfamiliar tones encountered through travel orinternational communication. Section 2 of this Recommendation advises against the use of new tones in order to avoidintroducing user difficulties.1.3 Where indications originate from a network (as proposed to a di
7、stant terminal), two situations may existbetween the origin of the indications and the user of an ISDN terminal:a) ISDN signalling is used throughoutb) In-band signalling is used in some parts of the connection.1.4 Considering that information is sent to an ISDN terminal on a D-channel, and that the
8、 terminal may transform itinto perceptible form, choices exist as to1)the most appropriate way of passing indications on to the user (e.g., bymeans of a display or by tones).2 Indications in an all-ISDN communication path2.1 It is recommended that no new tone (i.e., tones not in use in the PSTN) be
9、generated by an ISDN terminal.2.2 Tones are recommended where an auditory method other than “speech“ or announcements is chosen as themethod for a terminal to translate received D-channel ISDN information for a user. Such tones should be those used inthe PSTN in the country where the terminal is sit
10、uated (Recommendation E.180).2.3 It is recommended that where a terminal translates ISDN signalling to tones, such tones should be used withmeanings analogous to their meanings in the PSTN.2.4 It is recommended that the use of tones should be restricted to indicating the functions equivalent to the
11、tonesused in the PSTN and listed in Recommendation E.182, A.2. In some cases, notably dial tone, ringing tone, and busytone, these tones may be the best indicators even when other methods can be provided by a terminal.3 Indications when ISDN is interworking with another networkGiven that no tone rec
12、ognition is likely to be provided by any network element for translating a tone into anISDN signal for relaying to a terminal, it is recommended that any audible indication arising from a non-ISDN networkbe passed through an auditory channel to the ISDN terminal._1)The desirability of translating various ISDN indications, the situations governing such choices, and the relationships of these toterminal capability (particularly display capability), are subjects for further study.
