1、ITU-T RECNN*E.L27 94 = 4862571 0572247 398 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TELEPHONE NETWORK AND ISDN OPERATION, NUMBERING, ROUTING AND MOBILE SERVICE E.117 (06/94) TERMINAL DEVICES USED IN CONNECTION WITH THE PUBLIC TELEPHONE SERVICE (OTHE
2、R THAN TELEPHONES) ITU-T Recommendation E.117 (Previously ?CCITT Recommendation?) FOREWORD The IT Telecommunication Standardization Sector (IT-T) is a permanent organ of the International Telecom- munication Union. The -T is responsible for studying technical, operating and tariff questions and issu
3、ing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on t
4、hese topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki. March 1-12, 1993). ITU-T Recommendation E.117 was revised by the ITU-T Study Group 1 (1993-1996) and was approved under the WTSC Resolution No. 1 procedu
5、re on the 1st of June 1994. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O IT 1994 All rights reserved. No part of this publication may be reproduced or utilized in any form
6、 or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing fim the ITU. ITU-T RECMN*E.LL7 94 4862591 0592149 LbO CONTENTS Page 2 Annex A - Guidelines in setting national requirements for use of terminal equipment A.l Operating conditions . 2 A.2 A
7、voidance of misleading tones . 2 A.3 Avoidance of interference with network signalling 2 A.4 Transmission considerations . 2 Recommendation E.117 (W4) 1 SUMMARY Many terminal devices are available that may be substituted for, or used in conjunction with, subscribers telephones in the public telephon
8、e service. This Recommendation outlines some difficulties that may arise from this practice, particularly for the calling party. It also offers some guidelines to be considered when setting national requirements for terminal equipment. This Recommendation does not address issues related to PBXs, and
9、 it may not be applicable for telephone services entirely provided via the ISDN. ii Recommendation E.117 (W4) ITU-T RECMN*E.317 94 4862573 0572353 817 Recommendation E.117 TERMINAL DEVICES USED IN CONNECTION WITH THE PUBLIC TELEPHONE SERVICE (OTHER THAN TELEPHONES) (revised, 1994) 1 Many terminal de
10、vices are available that may be substituted for, or used in conjunction with, subscribers telephones. This Recommendation outlines some difficulties that may arise from this practice, particularly for the calling party. It also offers some guidelines to be considered when setting national requiremen
11、ts for terminal equipment. This Recommendation does not address issues related to PBXs, and it may not be applicable for telephone services entirely provided via the ISDN. 2 Such terminal devices include: a) a single terminating device such as: - a telephone answering machine to record a message; -
12、a telephone answering machine providing only a recorded announcement; - a facsimile terminal; - a data modem; b) a switching device offering automatic access to two or more terminal devices such as a telephone and a facsimile machine; c) an intelligent interactive terminal, which may, for example, p
13、rompt the calling party to enter commands from a telephone DTMF keypad. 3 Difficulties may arise when a call is answered in a manner that is incompatible with the terminal capability or reasonable expectation of the calling party. A charge will normally result from an effective network connection. H
14、owever, the call may have been ineffective from the viewpoint of providing the calling party with the desired transfer of information. A further concern is that, having answered the call, a device may return tones or signals that mislead the calling party into thinking that the call has not been ans
15、wered, and hence, has not been charged. 4 service, administrations should consider the following: In order to minimize the occurrence or the effect of such difficulties in the international public telephone a) the inclusion, where practicable, of the guidelines in the annex as a part of any national
16、 requirements for terminal devices to be used in connection with the telephone service; b) the possibility of a subscribers line being terminated on such an alternative device may be indicated in telephone directories (for an example, see Recommendation E. 123); c) In the long term, a preference for
17、 making available network based solutions, rather than for devices at the customers premises that require that every call be answered before the nature of the call can be determined. Recommendation E.117 (W94) 1 Annex A Guidelines in setting nationai requirements for use of terminal equipment (This
18、annex forms an integral part of this Recommendation) A.l Operating conditions 14.1.1 Delay in answering If the terminal device is other than a telephone, and has been set to automatically answer calls, it should answer as soon as practicable, taking into account the need to delay answer until the ca
19、lling party can be advised by the audible ringing tone %that a connection has been established. If theterminal has more than one function, e.g. a voice and a non-voice application, and it is configured for the voice application to take priority, it should delay answer for a reasonable period of time
20、. This should allow the call to be answered manually before the non-voice application answering procedure begins. If the terminal is configured for the non-voice application to take priority, it should answer as soon as practicable, taking account of the need to delay answer until the calling party
21、can be advised by the audible ringing tone that a connection has been established. If the terminal is a telephone answering and recording device, the delay before answering may be user selectable. A.1.2 Normal conditions for metering and supervision In answering and disconnecting a call, the device
22、should provide normal answer and disconnect conditions on the subscriber loop. It should also provide the same normal conditions for control of metering and supervision. A.1.3 Awareness A.1.3.1 The calling party should be made aware of the presence of a device other than a telephone: a) in the case
23、of a telephone answering machine, via a recorded announcement; or b) in the case of other devices, via suitable tones (or announcements). A.1.3.3 The recorded announcement from a telephone answering machine may include, for example, the following: - - - some indication that it is a recording device;
24、 the subscribers name, telephone number (and location), or business; clear instructions as to the functioning of the device (whether a message may be recorded, and if so, the moment when a message may be recorded). A.2 Avoidance of misleading tones After call answer, the device should not return ton
25、es that the calling party may confuse with normal network-generated tones (particularly, simulated ringing tone). A.3 Avoidance of interference with network Signalling The device should not interere with network signalling. This may be achieved by following the relevant T- and V-Series Recommendatio
26、ns. For applications not covered there, the G-Series are relevant. A.4 Transmission considerations Any device using recorded announcements (including synthesized voice) should provide a level and quality of speech such that the message will be intelligible to the caller. 2 Recommendation E.117 (W4) ITU-T RECMN*E.LL? 74 4b257L 0572353 b7L m Printed in Switzerland Geneva, 1994
