1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T E.360.2TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2002) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS International routing plan QoS routing and related traffic engineering methods Call routing and co
2、nnection routing methods ITU-T Recommendation E.360.2 ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS INTERNATIONAL OPERATION Definitions E.100E.103 General provisions concerning Administrations E.104E.119 General provisions concerning
3、 users E.120E.139 Operation of international telephone services E.140E.159 Numbering plan of the international telephone service E.160E.169 International routing plan E.170E.179 Tones in national signalling systems E.180E.189 Numbering plan of the international telephone service E.190E.199 Maritime
4、mobile service and public land mobile service E.200E.229 OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING IN THE INTERNATIONAL TELEPHONE SERVICE Charging in the international telephone service E.230E.249 Measuring and recording call durations for accounting purposes E.260E.269 UTILIZATION
5、OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON-TELEPHONY APPLICATIONS General E.300E.319 Phototelegraphy E.320E.329 ISDN PROVISIONS CONCERNING USERS E.330E.349 INTERNATIONAL ROUTING PLAN E.350E.399 NETWORK MANAGEMENT International service statistics E.400E.409 International network management E.410E
6、.419 Checking the quality of the international telephone service E.420E.489 TRAFFIC ENGINEERING Measurement and recording of traffic E.490E.505 Forecasting of traffic E.506E.509 Determination of the number of circuits in manual operation E.510E.519 Determination of the number of circuits in automati
7、c and semi-automatic operation E.520E.539 Grade of service E.540E.599 Definitions E.600E.649 Traffic engineering for IP-networks E.650E.699 ISDN traffic engineering E.700E.749 Mobile network traffic engineering E.750E.799 QUALITY OF TELECOMMUNICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPEND
8、ABILITY PLANNING Terms and definitions related to the quality of telecommunication services E.800E.809 Models for telecommunication services E.810E.844 Objectives for quality of service and related concepts of telecommunication services E.845E.859 Use of quality of service objectives for planning of
9、 telecommunication networks E.860E.879 Field data collection and evaluation on the performance of equipment, networks and services E.880E.899 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. E.360.2 (05/2002) i ITU-T Recommendation E.360.2 QoS routing and related tr
10、affic engineering methods Call routing and connection routing methods Summary The E.360.x series of Recommendations describes, analyzes, and recommends methods which control a networks response to traffic demands and other stimuli, such as link failures or node failures. The functions discussed and
11、recommendations made related to traffic engineering (TE) are consistent with the definition given in the Framework document of the Traffic Engineering Working Group (TEWG) within the Internet Engineering Task Force (IETF): Internet Traffic Engineering is concerned with the performance optimization o
12、f operational networks. It encompasses the measurement, modelling, characterization, and control of Internet traffic, and the application of techniques to achieve specific performance objectives, including the reliable and expeditious movement of traffic through the network, the efficient utilizatio
13、n of network resources, and the planning of network capacity. The methods addressed in the E.360.x series include call and connection routing, QoS resource management, routing table management, dynamic transport routing, capacity management, and operational requirements. Some of the methods proposed
14、 herein are also addressed in or are closely related to those proposed in ITU-T Recs E.170 to E.179 and E.350 to E.353 for routing, E.410 to E.419 for network management and E.490 to E.780 for other traffic engineering issues. The recommended methods are meant to apply to IP-based, ATM-based, and TD
15、M-based networks, as well as the interworking between these network technologies. Essentially, all of the methods recommended are already widely applied in operational networks worldwide, particularly in PSTN networks employing TDM-based technology. However, these methods are shown to be extensible
16、to packet-based technologies, that is, to IP-based and ATM-based technologies, and it is important that networks which evolve to employ these packet technologies have a sound foundation of methods to apply. Hence, it is the intent that the methods recommended in this series of Recommendations be use
17、d as a basis for requirements for specific methods, and, as needed, for protocol development in IP-based, ATM-based, and TDM-based networks to implement the methods. The methods encompassed in this Recommendation include traffic management through control of routing functions, which include QoS reso
18、urce management. Results of analysis models are presented which illustrate the tradeoffs between various approaches. Based on the results of these studies, as well as established practice and experience, methods are recommended for consideration in network evolution to IP-based, ATM-based, and/or TD
19、M-based technologies. Source ITU-T Recommendation E.360.2 was prepared by ITU-T Study Group 2 (2001-2004) and approved under the WTSA Resolution 1 procedure on 16 May 2002. ii ITU-T Rec. E.360.2 (05/2002) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agen
20、cy in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. 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
21、basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Re
22、solution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administrati
23、on and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability
24、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, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this
25、 Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2003 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written
26、 permission of ITU. ITU-T Rec. E.360.2 (05/2002) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 4 Abbreviations 2 5 Call routing methods 2 6 Connection (bearer-path) routing methods. 3 7 Hierarchical Fixed Routing (FR) path selection. 6 8 Time-Dependent Routing (TDR) path selection 8 9
27、State-Dependent Routing (SDR) path selection . 9 10 Event-Dependent Routing (EDR) path selection 11 11 Interdomain routing 12 12 Conclusions/recommendations. 14 Annex A Modelling of traffic engineering methods. 15 A.1 Network design comparisons . 22 A.2 Network performance comparisons 24 A.3 Single-
28、area flat topology vs. multi-area 2-level hierarchical network topology 26 A.4 Network modelling conclusions. 28 iv ITU-T Rec. E.360.2 (05/2002) Introduction In this Recommendation we assume the separation of “call routing“ and signalling for call establishment from “connection (or bearer-path) rout
29、ing“ and signalling for bearer-channel establishment. Call routing protocols primarily translate a number or a name, which is given to the network as part of a call setup, to a routing address needed for the connection (bearer-path) establishment. Call routing protocols are described for example in
30、Q.2761 for the Broadband ISDN Used Part (B-ISUP) call signalling, ATM990048 for bearer-independent call control (BICC), or virtual trunking, call signalling, H.323 for H.323 call signalling, GR99 for the media gateway control RFC2805 call signalling, and in HSSR99 for the session initiation protocol
31、 (SIP) call signalling. Connection routing protocols include for example Q.2761 for B-ISUP signalling, ATM960055 for PNNI signalling, ATM960061 for UNI signalling, DN99 for switched virtual path (SVP) signalling, and J00 for MPLS constraint-based routing label distribution protocol (CRLDP) signallin
32、g. A specific connection or bearer-path routing method is characterized by the routing table used in the method. The routing table consists of a set of paths and rules to select one path from the route for a given connection request. When a connection request arrives at its originating node (ON), th
33、e ON implementing the routing method executes the path selection rules associated with the routing table for the connection to determine a selected path from among the path candidates in the route for the connection request. In a particular routing method, the path selected for the connection reques
34、t is governed by the connection routing, or path selection, rules. Various path selection methods are discussed: fixed routing (FR) path selection, time-dependent routing (TDR) path selection, state-dependent routing (SDR) path selection, and event-dependent routing (EDR) path selection. ITU-T Rec.
35、E.360.2 (05/2002) 1 ITU-T Recommendation E.360.2 QoS routing and related traffic engineering methods Call routing and connection routing methods 1 Scope The E.360.x series of Recommendations describes, analyzes, and recommends methods which control a networks response to traffic demands and other st
36、imuli, such as link failures or node failures. The functions discussed and recommendations made related to traffic engineering (TE) are consistent with the definitions given in the Framework document of the Traffic Engineering Working Group (TEWG) within the Internet Engineering Task Force (IETF): I
37、nternet Traffic Engineering is concerned with the performance optimization of operational networks. It encompasses the measurement, modelling, characterization, and control of Internet traffic, and the application of techniques to achieve specific performance objectives, including the reliable and e
38、xpeditious movement of traffic through the network, the efficient utilization of network resources, and the planning of network capacity. The methods addressed in the E.360.x series include call and connection routing, QoS resource management, routing table management, dynamic transport routing, cap
39、acity management, and operational requirements. Some of the methods proposed herein are also addressed in or are closely related to those proposed in ITU-T Recs E.170 to E.179 and E.350 to E.353 for routing, E.410 to E.419 for network management, E.490 to E.780 for other traffic engineering issues.
40、The recommended methods are meant to apply to IP-based, ATM-based, and TDM-based networks, as well as the interworking between these network technologies. Essentially, all of the methods recommended are already widely applied in operational networks worldwide, particularly in PSTN networks employing
41、 TDM-based technology. However, these methods are shown to be extensible to packet-based technologies, that is, to IP-based and ATM-based technologies, and it is important that networks which evolve to employ these packet technologies, have a sound foundation of methods to apply. Hence, it is the in
42、tent that the methods recommended in this series of Recommendations be used as a basis for requirements for specific methods and, as needed, for protocol development in IP-based, ATM-based, and TDM-based networks, to implement the methods. Hence the methods encompassed in this series of Recommendati
43、ons include: traffic management through control of routing functions, which include call routing (number/name translation to routing address), connection routing, QoS resource management, routing table management, and dynamic transport routing; capacity management through control of network design,
44、including routing design; operational requirements for traffic management and capacity management, including forecasting, performance monitoring, and short-term network adjustment. Results of analysis models are presented which illustrate the tradeoffs between various approaches. Based on the result
45、s of these studies as well as established practice and experience, TE methods are recommended for consideration in network evolution to IP-based, ATM-based, and/or TDM-based technologies. 2 References See clause 2 of Rec. ITU-T E.360.1. 2 ITU-T Rec. E.360.2 (05/2002) 3 Definitions See clause 3 of Re
46、c. ITU-T E.360.1. 4 Abbreviations See clause 4 of Rec. ITU-T E.360.1. 5 Call routing methods Call routing entails number (or name) translation to a routing address, which is then used for connection establishment. Routing addresses can consist, for example, of: a) E.164 ATM end system addresses (AES
47、As) E.191; b) network routing addresses (NRAs) E.353; and/or c) IP addresses S94. As discussed in ITU-T Rec. E.360.4, a TE requirement is the need for carrying E.164-AESA addresses, NRAs, and IP addresses in the connection-setup information element (IE). In that case, E.164-AESA addresses, NRAs, and
48、 IP addresses become the standard addressing method for interworking across IP-, ATM-, and TDM-based networks. Another TE requirement is that a call identification code (CIC) be carried in the call-control and bearer-control connection-setup IEs in order to correlate the call-control setup with the
49、bearer-control setup (Q.1901, ATM990048). Carrying these additional parameters in the Signalling System 7 (SS7) ISDN User Part (ISUP) connection-setup IEs is referred to as the bearer independent call control (BICC) protocol. Number (or name) translation, then, should result in the E.164-AESA addresses, NRAs, and/or IP addresses. NRA formats are covered in E.353, and IP-address formats in S94. The AESA address has a 20-byte format as shown in Figure 1a. E.191. E.360.2_F01aAESA addressIDP DSPIDIAFIFigure 1a
