ITU-T E 491-1997 Traffic Measurement by Destination Quality of Service Network Management and Traffic Engineering - Traffic Engineering - Measurement and Recording of Traffic - Serv.pdf

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1、INTERNATIONAL TELECOMMUNICATION UNION lTU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU E.491 (05197) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Quality of service, network management and traffic engineering - Traffic engineering - Measurement and

2、 recording of traffic Traffic measurement by destination ITU-T Recommendation E.491 (Previously CCITT Recommendation) ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS OPERA TION, NUMBERING, ROUTING AND MOBILE SER VICES INTERNATIONAL OPE

3、RATION E. 100-E.229 OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING IN THE E.230-E.299 INTERNATIONAL TELEPHONE SERVICE UTILIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON- E.300-E.329 TELEPHONY APPLICATIONS ISDN PROVISIONS CONCERNING USERS E.330-E.399 QUALITY OF SERVICE, NETWORK MA

4、NAGEMENTAND TRAFFIC ENGINEERING NETWORK MANAGEMENT E.400-E.489 International service statistics E.400-E.409 Intemational network management E.410-E.419 Checking the quality of the international telephone service E.420-E.489 TRAFFIC ENGINEERING E.490-E.799 Measureme Forecasting of traffic E.506-E.509

5、 Determination of the number of circuits in manual operation E.510-ES19 Determination of the number of circuits in automatic and semi-automatic operation E.520-E.539 Grade of service E.540-E.599 Definitions E.600-E.699 ISDN traffic engineering E.700-E.749 Mobile network traffic engineering E.750-E.7

6、99 E.800-E.899 QUALITY OF TELECOMMUNICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPENDABILITY PLANNING Terms and definitions related to the quality of telecommunication services E.800-E.809 Models for telecommunication services E.810-E.844 Objectives for quality of service and related concept

7、s of telecommunication services E.845-E.859 Use of quality of service objectives for planning of telecommunication networks E.860-E.879 Field data collection and evaluation on the performance of equipment, networks and services E.880-E.899 For further details, please refer to ITU-T List of Recommend

8、ations. ITU-T RECOMMENDATION E.491 TRAFFIC MEASUREMENT BY DESTINATION Summary This Recommendation outlines two approaches to destination-based measurement: call detail records and direct destination measurements. Three different methods of using call detail records are explained. Source ITU-T Recomm

9、endation E.491 was prepared by ITU-T Study Group 2 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 26th of May 1997. Recommendation E.491 (0997) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommuni-

10、cations. 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 World Telec

11、ommunication 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 laid down in

12、 WTSC Resolution No. 1. In some areas of information technology which fall 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 telecommunication

13、administration and a recognized operating agency. INTELLECTLJAL 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 evidence, valid

14、ity or applicability of claimed Intellectual Property Rights, whether asserted by 1TU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU hadhad not received notice of intellectual property, protected by patents, which may b

15、e 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 1997 All rights reserved. No part of this publication may be reproduced or utilized in any fo

16、rm or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. Il Recommendation E.491 (05/97) 6 7 8 - STD-ITU-T RECMN E.493-ENGL 1997 4862573 Ob3b4L4 703 CONTENTS Scope Introduction Terms and definitions . References Measurement from

17、call detail records 5.1 Description 5.2 Application Direct destination measurements 6.1 Description 6.2 Application Measurement principles Recommendation history Page 1 1 1 2 2 2 3 4 4 4 4 4 Recommendation E.491 (05197) . 111 Recommendation E.491 TRAFFIC MEASUREMENT BY DESTINATION (Geneva, i 99 7) 1

18、 Scope This Recommendation outlines two approaches to destination-based measurement: call detail records and direct destination measurements. Three different methods of using call detail records are explained. 2 Introduction Traditionally, traffic measurements form network planning and other purpose

19、s have been taken on a circuit group basis. These measurements could be used directly for circuit group administration, and, for hierarchical networks, can be combined with pre-defined routing information to approximate point-to-point traffic matrices. However, these measurements do not allow accura

20、te evaluation of end-to-end blocking, and thus, do not reflect the quality of service perceived by customers. In addition, with widespread use of network management controls and dynamic routing where the concept of final trunk groups vanishes, destination-based measurements are required to allow eva

21、luation of network performance and Grade of Service (GOS). The use of destination-based traffic measurements can be beneficial in all three cycles of network operations which are described in Recommendation E.490. Because service problems are identified directly, trunk group additions and adjustment

22、s become straightforward and so do network traffic management actions. It should be noted that the advent of multi-service integrated networks will require that data measured on a destination basis be further split into classes of service. This will be necessary in order to ensure service specific p

23、erformance objectives in an environment where each service has its own traffic characteristics. 3 Terms and definitions This Recommendation defines the following terms. 3.1 call detail record (CDR): Is an instance of measurement by destination using incoming traffic. CDRs may be done on sampling bas

24、is but can also be made continuously. The term Call Record (CR) in Recommendation E.502 means the same as a CDR. 3.2 outgoing traffic. 3.3 e.g. some call attempts may be charged even if the call is not completed. 3.4 3.5 - direct destination measurement: Produces similar information to CDR measureme

25、nt but by monitoring chargeable calls: comprise completed calls and other kind of calls which are charged for a particular reason, unchargeable calls: Call attempts which are not charged are called unchargeable calls. clearing code in a CDR is: for unsuccessful call attempt (term used in Recommendat

26、ion E.502) the cause for failure specified by ES02 for successful call attempt (term used in Recommendation E.502) the result of call attempt as specified by ES02 type 16. type 16; - 3.6 3.7 calls. An all-ticket differs from a toll-ticket by being made for all call attempts, not only for chargeable

27、calls. clearing between operators: Means exchanging traffic information between operators for billing purposes. toll-ticketing: Is an alternative way to pulse charging for billing calls. Toll-tickets are made for chargeable Recommendation E.491 (05/97) 1 Other terms and definitions are given in Reco

28、mmendation E.600. 4 References The following ITU-T Recommendations, and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are

29、 subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - CCITT Recommendat

30、ion ES02 (1 992), Traflc measurement requirements for digital telecommunication exchanges. ITU-T Recommendation E.600 (1993), Terms and definitions of trafic engineering. CCITT Recommendation E.490 (1992), Traffic measurement and evaluation - General survey. - - 5 Measurement from call detail record

31、s 5.1 Description There are three kinds of call detail records: A B C Creation of CDRs CDRs of type A are created for incoming calls in exchanges selected for traffic engineering purposes. The CDRs for billing (types B and C) are made in the originating exchange. When necessary, CDRs of types B and

32、C are made in transit exchanges for clearing between operators and for monitoring the transit traffic of individual operators. This information for clearing between operators and traffic studies is often collected using counters but it can also be made with CDRs. A CDR of types B and C is created fo

33、r occupations longer than some given T or when a cost limit is reached. Contents of CDRs For details of information to be recorded, reference is made to measurement types 15 and 16 in Recommendation E.502. The times in a CDR should be recorded in a precision determined by the application of the meas

34、urement. (Measurements for delay calculation would require considerably more precision than those for billing purposes.) In CDRs of types B and C the size of the ticket should be rather small for performance reasons. A CDR which is not used as a ticket but is made for only traffic measurement purpos

35、es, possibly on sampling basis. A CDR which is created for every chargeable call (toll-ticket). A CDR which is created for every call attempt, whether charged or not (all-ticket). Procedure to process CDRs i) CDRs of type A and those CDRs of type B which are created in origination exchange are handl

36、ed as follows: The CDRs are stored locally, until sent or polled from a central area for direct access or downstream batch processing. Type C: CDRs which are created in originating exchange are handled as follows: The CDRs must be divided into chargeable and unchargeable call CDRs in the originating

37、 exchange, or another way is that this exchange only contains a small buffer which is being polled with a short polling interval. Unchargeable call CDRs may be further divided into subsets according to the clearing code. i) Or in some other exchange which has been selected as a point where tickets a

38、re created. 2 Recommendation E.491 (0997) STD.ITU-T RECMN E.47L-ENGL 1997 D 4b259L Ob3b4L7 412 CDRs for calls with a given clearing code are stored into logically separate files or databases, physically it may be the same database or file depending on the implementation. The CDR information is kept

39、for a certain time depending on the clearing code. This time may vary from zero to relatively long times. The CDRs for chargeable calls are stored in a file or database and from there they are transferred, for instance once a day, to a billing system, from where information for billing and customer

40、trafic studies is obtained. Unchargeable call attempts also get a CDR with a clearing code and the CDRs are transferred almost immediately to a traffic monitor where they are treated according to the clearing code. In a fault situation the exchange, or the unit polling the exchange if the exchange i

41、s not checking the clearing code, can automatically limit the flow of unsuccessful calls coming to the traffic monitor by taking a random sample. iii) Types B and C: CDRs which are created in transit exchanges can be handled as follows: CDRs from chargeable calls are stored into a file in the exchan

42、ge or after exchange in a similar way as in ii). The CDRs are transferred in suitable intervals to be processed for clearing between operators and trafic studies. Processing time for CDRs CDRs from chargeable calls are used for billing, clearing between operators and for traffic studies, all CDRs ar

43、e usually processed but the processing period can be long, for instance a day. The following two paragraphs apply to type C (all-ticketing): Division of CDRs to those originating from chargeable calls versus unchargeable call attempts by checking the clearing code must be made continuously or with a

44、 short period. The period is determined by the needs of network management for treating unchargeable call attempts. CDRs for unchargeable call attempts are processed by network management and they should be processed almost in real-time. During a period of low traffic it could be conceivable that un

45、chargeable CDRs are not processed, this may not be a good practise since predicting silent periods is likely to be more uncertain in the future. 5.2 Application The CDR information can be used for GOS statistics, billing and revenue settlements but also for various traffic measurements. If all-ticke

46、ting is used, CDRs can be used also for network management. Using an off-line system, a large variety of traffic measurements such as Erlang loading, 24-hour traffic distribution, call duration, Set-up time, conversation time, Answer Seizure Ratio (ASR), GOS and overflow, can be derived from the CDR

47、. If all-ticketing is used, several interesting GOS parameters, like the number of failures from a given originating subscriber to a given destination subscriber can be obtained from CDRs. These measurements can be computed by either origin, using the inlet source, or by destination, using the diall

48、ed digits, for both terminal and transit traffic. Each measurement can be further broken down by exchange, trunk group, circuit, area code or even customer number. The use of off-line reference tables to indicate the foreign country, city, exchange, the signalling type, facility type, etc. allows an

49、 almost unlimited flexibility in the sorting and grouping of the statistics extracted (Le. by country, alternate route, high usage, final). To avoid the double counting of traffic, any call records for calls switching through more than one exchange (within the same network) is matched by specific fields such as dialled digits, inlet source, identity of exchange outlet and regrouped into a complete record consisting of an incoming portion, an outgoing portion and as many intermediate portions as required (depending on the number of intermediate exchanges). Recomm