ITU-T E 411-2000 International Network Management - Operational Guidance Series E Overall Network Operation Telephone Service Service Operation and Human Factors Quality of Service.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU E.41 I (03/2000) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Quality of service, network management and traffic engineering - Network management - International

2、 network management International network management - Operational guidance ITU-T Recommendation E.411 (Formerly CCITT Recommendation) ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS OPERA TION, NUMBERING, ROUTING AND MOBILE SERVICES I

3、NTERNATIONAL OPERATION Definitions General provisions concerning Administrations General provisions concerning users Operation of international telephone services Numbering plan of the international telephone service International routing plan Tones in national signalling systems Maritime mobile ser

4、vice and public land mobile service OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING IN THE INTERNATIONAL TELEPHONE SERVICE Charging in the international telephone service Measuring and recording call durations for accounting purposes UTILIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR

5、NON- TE LEP H ONY AP PLI CATI ONS General Phototelegraphy ISDN PROVISIONS CONCERNING USERS QUALITY OF SERVICE, NETWORK MANAGEMENT AND TRAFFIC ENGINEERING NETWORK MANAGEMENT International service statistics International network management Checking the quality of the international telephone service T

6、RAFFIC ENGINEERING Measurement and recording of traffic Forecasting of traffic Determination of the number of circuits in manual operation Determination of the num ber of circuits in automatic and semi-automatic operation Grade of service Definitions ISDN traffic engineering Mobile network traffic e

7、ngineering QUALITY OF TELECOMMUNICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPENDABILITY PLANNING Terms and definitions related to the quality of telecommunication services Models for telecommunication services Objectives for quality of service and related concepts of telecommunication servi

8、ces Use of quality of service objectives for planning of telecommunication networks Field data collection and evaluation on the performance of equipment, networks and services E. 1 00-E. 103 E.104-E.119 E. 120-E. 139 E. 140-E. 159 E. 1 60-E. 1 69 E. 170-E. 179 E. 1 80-E. 1 99 E.200-E.229 E.230-E.249

9、 E.260-E.269 E.300-E.319 E.320-E.329 E. 330-E. 399 E.400-E.409 E.420-E.489 E.490-E.505 E.506-E509 E.510-E519 E.520-E539 E.540-E599 E.600-E.699 E.700-E.749 E.750-E.799 E.800-E.809 E.810-E.844 E.845-E.859 E.860-E.879 E.880-E.899 For further details, please rer to ITD-T List of Recommendations. ITU-T R

10、ECOMMENDATION E.411 INTERNATIONAL NETWORK MANAGEMENT - OPERATIONAL GUIDANCE Summary Network management requires real-time monitoring of current network status and performance and the ability to take prompt action to control the flow of traffic when necessary (see Recommendation E.410). Operational g

11、uidance to meet these requirements, including a description of status and performance parameters, traffic controls and the criteria for their application are included in this Recommendation. It should be noted that the complete range of parameters and traffic controls are not necessary for the intro

12、duction of a limited network management capability; however, a comprehensive selection will bring substantial benefit (see clause YE.4 1 O). In addition, some guidance on beginning network management is provided, along with information on developing a network management centre and the use of common

13、channel signalling for network management purposes. Source ITU-T Recommendation E.411 was revised by ITU-T Study Group 2 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on 13 March 2000. Recommendation E.411 (03/2000) 1 FOREWORD ITU (International Telecommunication Union) is t

14、he United Nations Specialized Agency in the field of telecommunications. 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 standa

15、rdizing 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 these topics. The approval of Recommendations by t

16、he Members of the ITU-T is covered by the procedure laid down in 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 “Administratio

17、n“ is used for conciseness to indicate both a telecommunication 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

18、Right. The ITU takes no position concerning the evidence, 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

19、 of intellectual property, protected by patents, which 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 2000 All rights reserved. No part

20、 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 fi-om the ITU. 11 Recommendation E.411 (03/2000) CONTENTS Page 1 2 3 4 4.1 4.2 4.3 5 6 6.1 6.2 6.3 6.5 6.6 7 7.3 7.4 8 8.1 8.2

21、 9 9.2 9.3 9.4 10 10.1 10.2 Scope . Information requirements Network status and performance data . Interpretation of parameters Switching loss . Circuit congestion loss Distant network loss Criteria for action Network management actions . Expansive actions . Protective actions Actions during disaste

22、rs Performance parameters for NM organizations Exchange of information . Guidance on the use of common channel signalling for network management . General Information exchange for improving completion rate of international transit calls . . 7.4.1 Information for exchange . Beginning network manageme

23、nt Utilizing existing resources and capabilities . 8.1.1 Responsibility 8.1.2 Telephone operators . 8.1.4 Circuits . 8.1.3 Exchange capabilities Improving capabilities Considerations for the development of network management Advantages of the decentralized (distributed) approach . Advantages of the

24、centralized approach . Network management operations systems 9.4.1 Performance reports . 9.4.2 Other considerations Intelligent Network . Surveillance for an SCF via a signalling network . Surveillance for an SCF via circuit groups . Recommendation E.411 (03/2000) 1 2 9 10 10 10 10 11 11 13 13 14 14

25、 16 17 17 17 17 17 17 18 18 18 18 19 19 20 20 20 . 111 Annex A . Terminology for Intelligent Network A.l Adjunct (AD) A.2 A.3 Intelligent Peripheral (IP) A.4 A . 5 A.6 A.7 Call Control Function (CCF) Service Control Function (SCF) . Service Switching Function (SSF) Service Switching Point (SSP) . Se

26、rvice Node (SN) Page 20 20 20 21 21 21 22 22 iv Recommendation E.411 (03/2000) Recommendation E.411 INTERNATIONAL NETWORK MANAGEMENT - OPERATIONAL GUIDANCE (revised in 2000) 1 Scope Network management requires real-time monitoring of current network status and performance and the ability to take pro

27、mpt action to control the flow of traffic when necessary (see Recommendation E.4 1 O). Operational guidance to meet these requirements, including a description of status and performance parameters, traffic controls and the criteria for their application are included in this Recommendation. It should

28、 be noted that the complete range of parameters and traffic controls are not necessary for the introduction of a limited network management capability; however, a comprehensive selection will bring substantial benefit (see clause YE.4 1 O). In addition, some guidance on beginning network management

29、is provided, along with information on developing a network management centre and the use of common channel signalling for network management purposes. 2 Information requirements 2.1 Network management requires information of where and why difficulties are occurring or are likely to occur in the net

30、work. This information is essential to identify the source and effect of a difficulty at the earliest possible time, and will form the basis for any network management action which is taken. 2.2 a) b) c) The information relating to current difficulties can be obtained fi-om: real-time surveillance o

31、f the status and performance of the network; information fi-om telephone operators as to where they are experiencing difficulties, or where they are receiving customer complaints of difficulties; transmission system failure indicators and planned outage reports (these reports need not relate only to

32、 the network local to one Administration, but should reflect the whole international network); international or national exchange failures and planned outage reports; news media reports detailing unforeseen events which stimulate traffic (for example, natural disasters) . The information relating to

33、 difficulties which are likely to occur in the future will be reports of future planned outages of transmission systems; reports of future planned outages of international or national exchanges; knowledge of special events (for example, international sporting events, political elections); knowledge

34、of national holidays and festivals (e.g. Christmas Day, New Years Day); an analysis of past network performance. The system availability information point, defined in Recommendation M.72 1, will provide d) e) 2.3 obtained fi-om: a) b) c) d) e) 2.4 a ready source for much of the information indicated

35、 above. Recommendation E.411 (03/2000) 1 3 Network status and performance data 3.1 In order to identi where and when difficulties are occurring in the network, or are likely to occur, data will be required which will indicate the status and measure the performance of the network. Such data will requ

36、ire real-time collection and processing, and may require the use of thresholds (see 5.1). 3.2 Data may be collected in various ways which include counters in electromechanical exchanges which can be read manually when required (e.g. during periods of heavy traffic or special events), data output rep

37、orts fiom SPC exchanges, or computerized network management operations systems which can collect and process data fiom a large number of exchanges. 3.3 Network status/performance information includes information on the status of exchanges, circuit groups, common channel signalling systems and transm

38、ission equipment. This status/performance information can be provided by one or more types of displays. These may include printers, video displays, and/or indicators/graphical representation on a display board or network management console. To be useful, network status indicators should be available

39、 as rapidly as possible. 3.3.1 - Exchange status information includes the following: Load measurements - These are provided by attempt counts, usage or occupancy data, data on the percent of real-time capacity available (or in use), blocking rates, percentage of equipment in use, counts of second tr

40、ials, etc.; Congestion measurements - These are provided by measurements of the delay in serving incoming calls, holding times of equipment, average call processing and Set-up time, queue lengths for common control equipment (or software queues), and counts of equipment time-outs, etc.; - Service av

41、ailability of exchange equipment - This information will show when major items of equipment are made busy to traffic. This could highlight a cause of difficulty or give advance warning that difficulties could arise if demand increases; Congestion indicators - In addition to the above, indicators can

42、 be provided by SPC exchanges which show the degree of congestion. These indicators can show: moderate congestion: level 1; serious congestion: level 2; unable to process calls: level 3. NOTE - While this is desirable, SPC exchanges may not be able to provide a level 3 indicator during catastrophic

43、failures. Network management control status indicators - Indicators can be provided to show controls that are active throughout a time interval, such as 30 seconds, or on occurrence to show controls that are added or deleted. The availability of specific exchange status information will depend on th

44、e switching technology employed by each Administration. Details of exchange measurements are found in Recommendations ES02 and 4.544. 3.3.2 - status of service types; - - - Circuit group status information relates to the following: status of all circuit groups available to a destination; status of i

45、ndividual circuit sub-groups in a circuit group; status of circuits on each circuit group. 2 Recommendation E.411 (03/2000) Status indicators can be provided to show when the available network is fully utilized by indicating: - - - This would indicate that congestion is present or imminent. Status i

46、nformation can be provided to show the availability of the network for service, by reporting the number or percentage of circuits on each circuit group that are made busy or are available for traffic. This information could identify the cause of difficulty or give advance warning that difficulties m

47、ay arise as the demand increases. An indicator should be provided to alert network managers, when the configuration or routing data is changed, for example, when a circuit group is deleted. 3.3.3 Common channel signalling system status provides information that will indicate failure or signalling co

48、ngestion within the system. It includes such items as: - receipt of a transfer prohibited signal (Signalling Systems Nos. 6 and 7); - initiation of an emergency restart procedure (Signalling System No. 6); - presence of a signalling terminal buffer overflow condition (Signalling System No. 6); - sig

49、nal link unavailability (Signalling System No. 7); - signal route unavailability (Signalling System No. 7); - destination inaccessible (Signalling System No. 7). This information may identify the cause of difficulty or give advance warning that difficulties may arise as the demand increases. Details are shown in Recommendations E.415 and E.505. 3.3.3.1 Network management actions may help to reduce congestion in common channel signalling systems by reducing traffic being offered to common channel signalling circuit groups, or by diverting traffic to conventional signalling circuit groups. 3