1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T E.360.5TELECOMMUNICATION 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 Transport routing m
2、ethods ITU-T Recommendation E.360.5 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 users E.120E.139
3、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 mobile service and
4、 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 OF THE INTERNATION
5、AL 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.419 Checking the
6、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 automatic and semi-automat
7、ic 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 DEPENDABILITY PLANNING T
8、erms 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 telecommunication
9、 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.360.5 (05/2002) i ITU-T Recommendation E.360.5 QoS routing and related traffic engineering
10、methods Transport 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 recommendations made, related to tr
11、affic 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 of operational networks. It encomp
12、asses 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 utilization of network resources, and the p
13、lanning 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 herein are also addressed in, or
14、 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 TDM-based networks, as well as th
15、e 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 to packet-based technologies, t
16、hat 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 used as a basis for requirements f
17、or 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 resource management. Results of ana
18、lysis 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 TDM-based technologies. Source ITU
19、-T Recommendation E.360.5 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.360.5 (05/2002) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunica
20、tions. 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 basis. The World Telecommunicati
21、on 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 Resolution 1. In some areas of inf
22、ormation 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 administration and a recognized operating ag
23、ency. 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 of claimed Intellectual Property
24、 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 Recommendation. However, implem
25、entors 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 permission of ITU. ITU-T Rec. E
26、.360.5 (05/2002) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 4 Abbreviations 2 5 Dynamic transport routing principles . 2 6 Dynamic transport routing examples 6 7 Reliable transport network design 11 7.1 Transport link design models . 13 7.2 Node design models . 14 8 Conclusions/reco
27、mmendations. 15 Annex A Modelling of traffic engineering methods. 16 A.1 Dynamic transport routing capacity design 16 A.2 Performance for network failures. 17 A.3 Performance for general traffic overloads 19 A.4 Performance for unexpected overloads 19 A.5 Performance for peak-day traffic loads 20 iv
28、 ITU-T Rec. E.360.5 (05/2002) Introduction This Recommendation describes and analyzes transport network architectures in light of evolving technology for integrated broadband networks. Dynamic transport routing offers advantages of simplicity of design and robustness to load variations and network f
29、ailures. Dynamic transport routing can combine with dynamic traffic routing to shift transport bandwidth among node pairs and services through use of flexible transport switching technology. Dynamic transport routing can provide automatic link provisioning, diverse link routing, and rapid link resto
30、ration for improved transport capacity utilization and performance under stress. We present reliable transport routing models to achieve reliable network design, so as to provide service for predefined restoration objectives for any transport link or node failure in the network and continue to provi
31、de connections to customers with essentially no perceived interruption of service. We show that robust routing techniques such as dynamic traffic routing, multiple ingress/egress routing, and logical link diversity routing improve response to node or transport failures. Cross-connect devices, such a
32、s optical cross-connects (OXCs), are able to node transport channels, for example OC48 channels, onto different higher-capacity transport links such as an individual WDM channel on a fiberoptic cable. Transport paths can be rearranged at high speed using OXCs, typically within tens of milliseconds s
33、witching times. These OXCs can reconfigure logical transport capacity on demand, such as for peak day traffic, weekly redesign of link capacity, or emergency restoration of capacity under node or transport failure. Rearrangement of logical link capacity involves reallocating both transport bandwidth
34、 and node terminations to different links. OXC technology is amenable to centralized traffic management. There is recent work in extending MPLS control capabilities to the setup of layer 2 logical links through OXCs, this effort dubbed multiprotocol lambda switching, after the switching of wavelengt
35、hs in dense wavelength division multiplexing (DWDM) technology ARDC99. ITU-T Rec. E.360.5 (05/2002) 1 ITU-T Recommendation E.360.5 QoS routing and related traffic engineering methods Transport routing methods 1 Scope The E.360.x series of Recommendations describes, analyzes, and recommends methods w
36、hich control a networks response to traffic demands and other stimuli, 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
37、 Group (TEWG) within the Internet Engineering Task Force (IETF): Internet 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 ach
38、ieve specific performance objectives, including the reliable and expeditious 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 ma
39、nagement, routing table management, dynamic transport routing, capacity 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 netwo
40、rk 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 TDM-based networks, as well as the interworking between these network technologies. Essentially all of the methods recommended are already widely applied in o
41、perational networks worldwide, particularly in PSTN networks employing 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 technolo
42、gies have a sound foundation of methods to apply. Hence, it is the intent 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
43、methods. Hence the methods encompassed in this series of Recommendations 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 trans
44、port routing. capacity management through control of network design, 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 ill
45、ustrate the tradeoffs between various approaches. Based on the results 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 ITU-T Rec. E.3
46、60.1. 2 ITU-T Rec. E.360.5 (05/2002) 3 Definitions See clause 3 of ITU-T Rec. E.360.1. 4 Abbreviations See clause 4 of ITU-T Rec. E.360.1. 5 Dynamic transport routing principles An important element of network architecture is the relationship between the transport network and the traffic network. An
47、 illustration of a transport network is shown in Figures 1 and 2 illustrates the mapping of layer-2 logical links in the traffic network onto the layer-1 physical transport network of Figure 1. Some logical links overlay two or more fiber-backbone links. For example, in Figure 1, logical link AD tra
48、verses fiber-backbone links AB, BC, and CD. E.360.5_F1Logical link (layer 2)Fibre backbone links (layer 1)Node (traffic switch and transport switch)ACDBEFFigure 1/E.360.5 Transport network model Figure 2 further illustrates the difference between the physical transport network (layer 1) and the logi
49、cal transport network (layer 2). Logical links are individual logical connections between network nodes, which make up the logical link connections and are routed on the physical transport network. Logical links can be provisioned at given rates, such as T1, OC3, OC12, OC48, OC192, etc., and is dependent on the level of traffic demand between nodes. E.360.5_F2Logical (layer 2) transport network view Physical (layer 1) transport network viewFibre linkTrafficrouterLogicallinkOXC transportswitchACBA BDCDFigure 2/E.360.5 Logical (layer 2) and
