ITU-T E 410-1998 International Network Management - General Information - Series E Overall Network Operation Telephone Service Service Operation and Human Factors - Quality of Serv.pdf

1、 STD-ITU-T RECMN E-41O-ENGL 1998 4862591 Ob48690 975 W I NTERNATI ONAL TELECOM M U N I CATI ON UN I ON ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU E.41 O (03/98) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Quality of service, network manageme

2、nt and traffic engineering - Network management - International network management International network management - General information ITU-T Recommendation E.41 O (Previously CCIlT Recommendation) ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND H

3、UMAN FACTORS OPERA TION? NUMBERLNG, ROUTING AND MOBILE SER VICES INTERNATIONAL OPERATION OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING IN THE INTERNATIONAL TELEPHONE SERVICE UTILIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON- TELEPHONY APPLICATIONS ISDN PROVISIONS CONCERNING USE

4、RS E.330-E.399 QALITY OF SERVICE7 NETWORK MANAGEMENT AND TRAFFIC ENGINEERING NETWORK MANAGEMENT International service statistics E.400-E.409 11 international network management E.410-EA19 Checking the quality of the international telephone service E.420-E.489 TRAFFIC ENGINEERING QUALITY OF TELECOMMU

5、NICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPENDABILITY PLANNING For further details, please refer to ITU-T List of Recommendations. ITU-T RECOMMENDATION E.410 INTERNATIONAL NETWORK MANAGEMENT - GENERAL INFORMATION Summary The ever increasing demand for the international telephone service,

6、 coupled with the introduction of larger digital transmission and switching systems along with common channel signalling, has resulted in an international telephone network which is highly interconnected and interactive and increasingly vulnerable to overload and congestion. This revised Recommendat

7、ion gives an overview of the activities necessary to reduce the effect on service of any situation affecting unfavourably the international telephone network. Source ITU-T Recommendation E.410 was revised by ITU-T Study Group 2 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure o

8、n the 9th of March 1998. Recommendation E.410 (03198) i FOREWORD IT (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommuni- cations. The ITU Telecommunication Standardization Sector (IT-T) is a permanent organ of the IT. The ITLJ-T is responsible

9、 for studying technical, operating and tariff questions and issuing 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

10、 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 WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards a

11、re 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 administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The IT draws attention to the possibility th

12、at 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, validity or applicability of claimed Intellectual Propew Rights, whether asserted by IT members or others outside of the Recommend

13、ation development process. As of the date of approval of this Recommendation, the IT had not received notice of intellectual propeq, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information an

14、d are therefore strongly urged to consult the TSB patent database. O IT 1998 All rights reserved. No part 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 from the ITU. 11 Reco

15、mmendation E.410 (03/98) . STDmITU-T RECMN E.4LO-ENGL 1798 = 4862591 0648674 510 CONTENTS Introduction Definition of international network management . Objective of network management . Principles of international network management . 4.1 4.2 4.3 4.4 Benefits derived from international network manag

16、ement Utilize all available circuits Keep all available circuits filled with traffic which has a high probability of resulting in effective calls . When all available circuits are in use, give priority to calls requiring a minimum number of circuits to form a connection Inhibit switching congestion

17、and prevent its spread . Network management functions . Cooperation and coordination Further Recommendations on network management . Annex A . Terminology for network management . Recommendation E.410 (03/98) Page 1 1 2 2 2 2 2 2 2 3 3 3 5 . 111 _ - STD-ITU-T RECMN E.41O-ENGL 1778 4862571 Ob48b75 45

18、7 Recommendation E.410 INTERNATIONAL NETWORK MANAGEMENT - GENERAL INFORMATION (revised in 1998) 1 Introduction The demand for international telephone service continues to increase substantially by more volume and new types of traffic, e.g. ISDN traffic, IN traffic. This increasing demand has been me

19、t by advances in both technology and operational techniques. The growth of traffic has also required the development of larger transmission systems and exchanges to provide the capacity and more advanced monitoring and control facilities to meet the required grade of service. With the continued grow

20、th of the international automatic service, direct supervision and control over traffic has decreased since operators are no longer involved in establishing most calls. In addition to the above, the introduction of larger digital transmission and switching systems, along with common channel signallin

21、g, has resulted in an international telephone network which is highly interconnected and interactive, and which has become increasingly vulnerable to overload and congestion. This overload and congestion can occur with little or no advance warning. A number of events may arise which can have a serio

22、us effect on the international telephone service. Among these events are: abnormal increases in traffic demand. The events which give rise to such traffic demand may be foreseen (eg national or religious holidays, international sporting events) or unforeseen (e.g. natural disasters, political crises

23、); focused overloads, and, in particular, mass-calling; congestion in connected networks; difficulties in meeting the requirements of international traffic resulting (for example) from delays in the provision of additional circuits or equipment; failures of international or national exchanges; plann

24、ed outages of transmission systems and exchanges; failures of international or national transmission systems; unreachable destinations for certain types of traffic like traffic demanding, e.g. specific transmission medium requirement; mass repeated events from ISDN terminals; large influence on the

25、network by the status of private LAN networks and its terminals. These events can lead to congestion which, if uncontrolled, may spread and thus seriously degrade the service in other parts of the international network. Considerable benefits can be derived for the international network as a whole if

26、 prompt action is taken to control the effect on service of such events. In addition, as the telephone network migrates toward ISDN, interworking with other networks will develop. With interworking, failure or congestion in one network, or in the interface between networks, can have an adverse impac

27、t on the performance of the connected network(s). The above considerations have led to the development of “international network management“, which encompasses all the activities necessary to reduce the effect on service of any situation affecting unfavourably the international telephone network. NO

28、TE - Much of the guidance on international network management may be applicable in national networks. 2 2.1 when necessary to control the flow of traffic. Definition of international network management international network management is the function of supervising the international network and taki

29、ng action Recommendation E.410 (03/98) 1 STD-ITU-T RECMN E.4LO-ENGL II998 4862591 Ob48b9b 393 Network management requires real-time monitoring and measurement of current network status and performance, and the ability to take prompt action to control the flow of traffic. 3 Objective of network manag

30、ement The objective of network management is to enable as many calls as possible to be successfully completed. This objective is met by maximizing the use of all available equipment and facilities in any situation through the application of the principles given below. 4 Principles of international n

31、etwork management 4.1 Utilize all available circuits There are periods when, due to changing traffic patterns, the demand for service cannot be met by the available circuits in the normal routing. At the same time, many circuits to other locations may be idle due to differences in calling patterns c

32、aused by time zones, local calling habits, or busy season variations. After negotiation and agreement amongst the Administrations affected, some or all of the unusually heavy traffic can be redirected to this idle capacity for completion. There are requirements that make it necessary to look at each

33、 type of traffic andor service type individually, and to use the available equipment according to the demands for each type of trafic. 4.2 Keep all available circuits filled with traffic which has a high probability of resulting in effective calls The telephone network is generally circuit-limited;

34、therefore, the number of simultaneous effective calls is strongly influenced by the number of available circuits. However, ineffective calls can occupy circuit capacity which would otherwise be available for effective calls. Therefore, identifiing those call attempts which are likely to be ineffecti

35、ve because of a situation in the network (e.g. a failure), and reducing them as close to their source as possible, will allow circuit capacity to be available for call attempts which have a higher probability of being effective. 4.3 When all available circuits are in use, give priority to calls requ

36、iring a minimum number of circuits to form a connection When telephone networks are designed using automatic alternate routing of calls, efficient operation occurs when traffic loads are at or below engineered values. However, as traffic loads increase above the engineered value, the ability of the

37、network to carry effective calls decreases since an increased number of calls require two or more circuits to form a connection. Such calls increase the possibility of one multi-link call blocking several potential calls. Thus, automatic alternate routing should be restricted to give preference to d

38、irect routed traffic during periods of abnormally high demand. 4.4 Inhibit switching congestion and prevent its spread A large increase in switching attempts can result in switching congestion when the switching capacity of an exchange is exceeded. If the switching congestion is left uncontrolled, i

39、t can spread to connected exchanges or networks and cause a further degradation of network performance. Controls should be applied which inhibit switching congestion by removing attempts from the congested exchange which have a low chance of resulting in a successful call. NOTE -Network management a

40、ssumes that the network is adequately engineered to meet the normal levels of traffic. 5 Benefits derived from international network management Among the benefits to be derived from international network management are: 5.1 increased revenue which is derived from an increase in successful calls. 2 R

41、ecommendation E.410 (03/98) 5.2 - improved customer relations; - - 5.3 - - improved service to the customer. This can lead, in turn, to: stimulation of customer calling rate; increased customer acceptance of new services. more efficient use of the network. This can result in: an increased return on

42、the capital invested in the network; an improvement in the ratio of effective to ineffective calls. 5.4 - - improved network planning information; - - improved public relations. greater awareness of the actual status and performance of the network. Such awareness can lead to: a basis by which networ

43、k management and maintenance priorities can be established; improved information on which future capital investment in the network can be decided; 5.5 protection of revenue and important services, particularly during severe network situations. 6 Network management functions Network management encomp

44、asses all of the activities necessary to identifi conditions which may adversely affect network performance and service to the customer, and the application of network controls to minimize their impact. This includes the following functions: monitoring the status and performance of the network on a

45、real-time basis, which includes collecting and analysing relevant data; detecting abnormal network conditions; investigating and identiing the reasons for abnormal network conditions; initiating corrective action and/or control; cooperating and coordinating actions with other network management cent

46、res, both domestic and international, on matters concerned with international network management and service restoration; cooperating and coordinating with other work areas (e.g. maintenance, operator services or planning) on matters which affect service; issuing reports of abnormal network situatio

47、ns, actions taken and results obtained to higher authority and other involved departments and administrations, as required: providing advance planning for known or predictable network situations. 7 Cooperation and coordination Effective network management depends on the prompt availability of inform

48、ation indicating when and where a problem is occurring, and a trained group working in cooperation with all parts of the telecommunications organization. Just as there is a need for coordination in planning and building the network, there also is a need for coordination in managing it. The network i

49、s such that equipment malfunctions or overloads frequently produce unacceptable performance at a distance from the physical location of the problem. Therefore, those who monitor and manage the network, both nationally and internationally, must cooperate to ensure satisfactory service. Network management is highly technical in nature, and depends on the skill and creativity of those who share an understanding of network management philosophy, objectives, terminology, tools and techniques. These items are specified in Recommendations E.41 O through E.4 15, an