1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU E.351 (03/2000) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Operation, numbering, routing and mobile services - ISDN provisions concerning users - International
2、 routing plan Routing of multimedia connections across TDM-, ATM- and IP-based networks ITU-T Recommendation E.351 (Formerly CCITT Recommendation) ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS OPERA TION, NUMBERING, ROUTING AND MOBIL
3、E SERVICES INTERNATIONAL 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 Numberi
4、ng plan of the international telephone service Maritime mobile service 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 accountin
5、g purposes UTILIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON- TE LEP H ONY AP PLI CATI ONS General Phototelegraphy ISDN PROVISIONS CONCERNING USERS E. 1 00-E. 103 E.104-E.119 E. 120-E. 139 E. 140-E. 159 E. 160-E. 169 E. 170-E. 179 E. 180-E. 189 E. 190-E. 199 E.200-E.229 E.230-E.249 E.260-E.
6、269 E.300-E.319 E.320-E.329 International routing plan E.35-E.399 QUALITY OF SERVICE, NETWORK MANAGEMENT AND TRAFFIC ENGINEERING NETWORK MANAGEMENT International service statistics International network management Checking the quality of the international telephone service TRAFFIC ENGINEERING Measur
7、ement and recording of traffic Forecasting of traffic Determination of the number of circuits in manual operation Determination of the number of circuits in automatic and semi-automatic operation Grade of service Definitions ISDN traffic engineering Mobile network traffic engineering QUALITY OF TELE
8、COMMUNICATION 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 services Use of quality of serv
9、ice objectives for planning of telecommunication networks Field data collection and evaluation on the performance of equipment, networks and services E.400-E.409 E.41 0-E.419 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.8
10、44 E.845-E.859 E.860-E.879 E.880-E.899 For further details, please rer to the list of ITD-T Recommendations. ITU-T RECOMMENDATION E.351 ROUTING OF MULTIMEDIA CONNECTIONS ACROSS TDM-, ATM- AND IP-BASED NETWORKS Summary There are many network operators who have implemented multiple networks using diff
11、erent network-layer (layer-3) routing protocols, which include TDM-, ATM-, and/or IP-based technology. Rapid growth of multimedia IP-based services has led in turn to ATM and IP technology being implemented and/or planned for PSTNs. Established routing methods are recommended for application across
12、network types (summarized in Table i), and include the following: a) E. 1 64NSAP-based number translationrouting; b) automatic generation of routing tables based on network topology and status; c) automatic update and synchronization of topology databases, d) dynamic route selection; and e) QoS reso
13、urce management. Signalling and information-exchange requirements needed to support these routing methods are recommended, and include the connectivity management and routing policy parameters summarized in Table 4. Source ITU-T Recommendation E.351 was prepared by ITU-T Study Group 2 (1997-2000) an
14、d was approved under the WTSC Resolution No. 1 procedure on 13 March 2000. Recommendation E.351 (03/2000) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a
15、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 Telecommunication Standardization Conference (WTSC), which meets every four
16、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 WTSC Resolution No. 1. In some areas of information technology which f
17、all 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 administration and a recognized operating agency. INTELLECTUAL PROPERTY
18、 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, validity or applicability of claimed Intellectual Property Rights, whether as
19、serted 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 of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are caut
20、ioned 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 of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and mi
21、crofilm, without permission in writing fi-om the ITU. 11 Recommendation E.351 (03/2000) CONTENTS 1 2 3 4 5 5.1 5.2 5.3 5.4 5.5 6 6.1 6.2 6.3 6.4 6.5 6.6 7 7.1 7.2 Scope . References . Definitions Abbreviations Recommended routing methods . Number translatiodrouting . Routing table management . 5.2.1
22、 Topology update 5.2.2 Status update 5.2.3 Query for status 5.2.4 Routing recommendation Route selection QoS resource management . QoS resource management steps . Bandwidth-allocation, bandwidth-protection, and priority-routing issues Other QoS routing constraints . 5.4.4 Priority queuing . 5.4.1 5.
23、4.2 5.4.3 5.4.5 Recommended standards developments for QoS resource management methods Harmonization of routing methods standards . Signalling and information exchange requirements Number translatiodrouting information-exchange parameters Routing table management information-exchange parameters . Ro
24、ute selection information-exchange parameters . QoS resource management information-exchange parameters . Harmonization of information-exchange standards Open routing application programming interface (MI) . Examples of internetwork routing Internetwork E uses a mixed route selection method . Intern
25、etwork E uses a single route selection method Annex A . TDM-based intranetwork routing methods . TDM-based number translationrouting . TDM-based routing table management and route selection . A.2.1 Fixed routing (FR) . A.2.2 Time-dependent routing (TDR) . A . 1 A.2 Recommendation E.351 (032000) Page
26、 1 3 4 4 7 9 9 10 10 10 11 11 12 12 13 17 17 17 18 18 20 20 22 22 23 24 24 25 26 27 27 27 28 28 . 111 A.2.3 State-dependent routing (SDR) A.2.4 Event-dependent routing (EDR) TDM-based QoS resource management . A.3 Annex B . ATM-based intranetwork routing methods B . 1 B.2 B.3 ATM-based number transl
27、ationrouting . ATM-based routing table management and route selection . ATM-based QoS resource management . Annex C - IP-based intranetwork routinghwitching methods IP-based number translationrouting . IP-based routing table management and route selection . IP-based QoS resource management . C . 1 C
28、.2 C.3 Appendix I . Bibliography . Page 29 30 30 30 31 31 32 35 37 37 37 43 iv Recommendation E.351 (03/2000) Introduction There are many network operators who have implemented multiple networks using different protocols, which include Public Switched Telephone Networks (PSTNs) which use Time Divisi
29、on Multiplexing (TDM) technology, Asynchronous Transfer Mode (ATM) technology, and/or Internet Protocol (IP) technology. The very rapid growth of data services driven primarily by multimedia IP-based services has led in turn to the rapid growth of ATM and IP technology being implemented and/or plann
30、ed for PSTNs. Also, there is interest in carrying traditional PSTN voice services over ATM- and IP-based networks, leading to the convergence in many instances of voice and data services onto a common network. Therefore it is important to address the intenvorking of voice and data services over TDM-
31、, ATM-, and IP-based PSTN networks, and - in particular - to address the intenvorking of routing methods across these different types of networks. This Recommendation addresses routing used within single networks and across different networks; it deals with both routing methods and the information e
32、xchange required to support such methods. The treatment of routing methods includes recommendations on: a) number translationrouting; b) routing table management; c) route selection; and d) quality-of-service (QoS) resource management. The signalling and information-exchange requirements of these ro
33、uting methods are also addressed and recommendations made. Various routing protocols are used in TDM-, ATM-, and IP-based networks. In TDM-based networks, for example, Recommendation E.350 describes fixed and dynamic routing methods for use in TDM-based networks. In ATM-based networks, for example,
34、the Private Network-to-Network Interface (PNNI) standard adopted by the ATM Forum ATM9600551 provides for: o exchange of node and link status information; automatic update and synchronization of topology databases; fixed and/or dynamic route selection based on topology and status information; and si
35、gnalling and information exchange standards. o o o In IP-based networks, for example, the open shortest path first (OSPF), border gateway protocol (BGP), multiprotocol label switching (MPLS), and other standards adopted by the Internet Engineering Task Force M98, S95 and J99 provide for all of the s
36、ame features listed above for PNNI, but in a connectionless IP-based packet network. There is interest in intenvorking fixed and dynamic routing methods across TDM-, ATM-, and IP-based networks to include fixed routing (FR), time-dependent routing (TDR), state-dependent routing (SDR), and event-depe
37、ndent routing (EDR) methods, applied primarily in non-hierarchical networks. A multimedia connection will often traverse more than one network type, and hence may be routed end-to-end using more than one fixed or dynamic routing method. This Recommendation covers the intenvorking of different types
38、of fixed and dynamic routing methods and their associated information-exchange needs at the interface across various network types, in order to complete a connection originating in one node and terminating in another, where the originating, via, and destination nodes may operate different routing me
39、thods. This Recommendation addresses the intenvorking of routing methods for all services including multimedia services and only considers point-to-point connections (multipoint connections are left for future work). Substantial improvements in network cost efficiency and robustness result fiom the
40、introduction of efficient routing. A fiamework is needed to support intenvorking of different routing methods and information-exchange across various TDM-, ATM-, and IP-based network types, perhaps implemented on different vendor equipment, for routing between network operators, national as well as
41、international. Standardisation of information flows is needed, so that switching equipment fiom Recommendation E.351 (03/2000) V different vendors can intenvork across various network types to implement routing strategies in a coordinated fashion. Routing intenvorking standards are needed for applic
42、ation to intenvorking between multivendor networks of various types. This includes the international network among many network operators who use different vendor equipment and networking protocols, including TDM-, ATM-, and IP-based protocols. More specifically, this Recommendation addresses the nu
43、mber translationrouting, routing table management, route selection, and quality-of-service (QoS) resource management methods needed for routing within each network type and for routing intenvorking between network types. In particular, the following established routing methods employed within the id
44、entified network type(s) are recommended for application across network types: a) the E. 164NSAP based number translationrouting methods applied in TDM- and ATM-based networks; b) the automatic generation of routing tables based on network topology and status applied in TDM-, ATM-, and IP-based netw
45、orks; c) the automatic update and synchronization of topology database methods applied in ATM- and IP-based networks; d) the dynamic route selection methods applied in TDM-based networks; and e) the QoS resource management methods applied in TDM-based networks. Table 1 summarizes the recommended rou
46、ting methods across various network technologies. In addition, this Recommendation identifies the signalling and information-exchange requirements needed to support these routing methods. These include: a) carrying E.164 NSAPs, international network routing addresses, and IP addresses in connection-
47、setup information elements (IEs); b) the topology update information exchange applied in ATM- and IP-based networks; c) the routing table design information exchange applied in TDM-based networks; d) the route selection information exchange applied in ATM-based networks; and e) originating-node-cont
48、rolled (source) routing, with specification of via and destination nodes in a parameter in a connection-setup E, and return of control to the originating node with a crankbackbandwidth-not-available parameter in the connection-release E. Table 4 summarizes the recommended signalling and information-
49、exchange parameters to support the routing methods recommended in Table 1, as well the recommended standards to support the parameters. vi Recommendation E.351 (03/2000) Recommendation E.351 ROUTING OF MULTIMEDIA CONNECTIONS ACROSS TDM-, ATM- AND IP-BASED NETWORKS (Geneva, 2000) 1 Scope This Recommendation addresses routing methods and information exchange needed within and between TDM-, ATM-, and IP-based network and routing technology. It recommends a compatible set of routing methods based on established practice, and also recommends compatible information exchange to s
