1、 STDmITU-T RECMN Q.118-ENGL 1997 I 4862571 Ob42510 288 I INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.118 (09197) SERIES Q: SWITCHING AND SIGNALLING Clauses applicable to ITU-T standard systems - Abnormal conditions - Abnormal conditions - Special rel
2、ease arrangements ITU-T Recommendation Q. 1 18 (Previously CCITT Recommendation) STDmITU-T RECMN Q=LLB-ENGL 1997 I YB62591 ObY25LL 114 I ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORK1 NG Q. I -Q.
3、 3 Q .4-Q. 59 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60-Q.99 CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Q.100-Q.119 General clauses Transmission clauses for signalling Control of echo suppressors Q.115 Q. 1 OO-Q. 1 O9 Q.l I 0-Q.114 Abnormal conditions Q.116-Q.l I9 SPECIFICATION
4、S OF SIGNALLING SYSTEMS No. 4 AND No. 5 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 SPECIFICATIONS OF SIGNALLING SYSTEM RI SPECIFICATIONS OF SIGNALLING SYSTEM R2 DIGITAL EXCHANGES INTERWORKING OF SIGNALLING SYSTEMS SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 PU
5、BLIC LAND MOBILE NETWORK INTERWORKING WITH SATELLITE MOBILE SYSTEMS INTELLIGENT NETWORK BROADBAND ISDN Q. 120-Q.249 Q.250-Q.309 Q. 3 1 O-Q. 399 Q.400-Q.499 Q.500-Q.599 Q. 7004.849 Q.600-Q.699 Q.850-Q.999 Q.1000-Q.l O99 Q.1100-Q.1199 Q.1200-Q.1999 Q.2000-Q.2999 For further details, please refer to IT
6、U-T List of Recommendations. STD-ITU-T RECMN Q-LLB-ENGL 1997 E 4862591 Ob42512 O50 ITU-T RECOMMENDATION Q.118 ABNORMAL CONDITIONS - SPECIAL RELEASE ARRANGEMENTS Summary This Recommendation describes arrangements for releasing connections resulting from abnormal conditions such as calling or called p
7、arty clearing. Source ITU-T Recommendation Q. 11 8 was revised by ITU-T Study Group 11 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 12th of September 1997. FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of t
8、elecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T 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 W
9、orld 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 these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure la
10、id down in WTSC Resolution No. 1. In some areas of information technology which fali within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecomm
11、unication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the eviden
12、ce, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which
13、 may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. o ITU 1998 All rights reserved. No part of this publication may be reproduced or utilized in
14、any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. Recommendation Q.118 (09/97) 11 STDoITU-T RECMN Q.33B-ENGL 1997 E 4462593 Ob42534 923 E CONTENTS Page 1 Answer signal not received by an outgoing exchange after recei
15、ving a number- received signal or number-received information (Systems No. 4 and FU) or after receiving an address complete signal (Systems No. 6 and No. 7) or after transmitting the ST signal (System No. 5) . 1 2 Delay in clearing by the calling subscriber in automatic service (arrangements made in
16、 the outgoing country) . 1 3 Clear-forward signal not received by the incoming exchange after sending a clear- back signal 2 Recommendation Q.118 (09/97) iii STD-ITU-T RECMN Q-LLB-ENGL 1997 4862591 Ob42535 8bT Recommendation Q.118 ABNORMAL CONDITIONS - SPECIAL RELEASE ARRANGEMENTS (revised in 1997)
17、1 Answer signal not received by an outgoing exchange after receiving a number-received signal or number-received information (Systems No. 4 and FU) or after receiving an address complete signal (Systems No. 6 and No. 7) or after transmitting the ST signal (System No. 5) It is recommended that arrang
18、ements should be made, either in the national network of the outgoing country or at the outgoing international exchange, for the connection to be released if an answer signal is not received within a delay period of 1.5 to 3 minutes as soon as it is known, or can be assumed, that the called subscrib
19、ers line has been reached. In addition, Administrations with ability to discriminate call answers may adopt a shorter interval which may be as low as 1 minute. However, this will require bilateral agreement. This represents an improvement from earlier values of 2 to 4 minutes. Application of this 1.
20、5- to 3-minute values is left to Administrations. If an Administration adopts a shorter delay period for this forced release condition, there will be a risk that the international connection will be released prematurely on calls not returning an answer signal. If the maximum delay of 3 minutes is ex
21、ceeded, it will of course involve an unnecessary occupation of international circuits. 2 Delay in clearing by the calling subscriber in automatic service (arrangements made in the outgoing country) In automatic working, arrangements must be made to clear the international connection and stop the cha
22、rging if, between 10-60 seconds, with a preferred value of 30 seconds after receipt of the clear-back signal, the calling subscriber has not cleared. Clearing of the international connection should preferably be controlled from the point where the charging of the calling subscriber is carried out. S
23、uch timed supervision may also be applied in semi-automatic service. During the establishment of a connection to a PABX extension, it is not appropriate to send a clear-back signal. However, if a PABX returns a clear-back condition, the duration must be less than 10 seconds, so that it would not uni
24、ntentionally clear the connection, especially on calls from networks with short time-out. For a call where the charging is applied to called party (e.g. free phone service), the time-out may be reduced. The value to be chosen is for further study. Recommendation Q.118 (09/97) 1 STD-ITU-T RECMN Q-LLB
25、-ENGL 1777 m 48b259L Ob42536 7Tb m 3 Clear-forward signal not received by the incoming exchange after sending a clear-back signal2 The incoming circuits at the incoming international exchange should include an arrangement for releasing the national part of the connection if, after sending a clear-ba
26、ck signal, a clear-forward signal is not received within 2 to 3 minutes (provided that a similar arrangement is not already made in the national network of the incoming country). This arrangement avoids indefinite blocking of the national circuits of the country of destination or of the subscribers
27、line in the case of interruptions of the line or of equipment faults. Since the call may be a semi-automatic call not including the time-out of clause 2 at the outgoing end, the expiry of the 2 to 3 minute time-out should not cause any alarm or blocking actions on the international circuit. * These
28、release arrangements may not be used within some regional networks. 2 Recommendation 4.118 (09/97) STDmITU-T RECMN Q-118-ENGL 1997 4862591 Ob42517 b32 Series A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series L Series M Series N Series O Series P Serie
29、s Q Series R Series S Series T Series U Series V Series X Series Z ITU-T RECOMMENDATIONS SERIES Organization of the work of the ITU-T Means of expression: definitions, symbols, classification General telecommunication statistics General tariff principles Overall network operation, telephone service,
30、 service operation and human factors Non-telephone telecommunication services Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Transmission of television, sound programme and other multimedia signals Protection agains
31、t interference Construction, installation and protection of cables and other elements of outside plant TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: international sound programme and television transmission
32、 circuits Specifications of measuring equipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communication Programming languages
