1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU E.350 (03/0 O) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Operation, numbering, routing and mobile services - ISDN provisions concerning users Dynamic Routing
2、Interworking ITU-T Recommendation E.350 (Previously CCITT Recommendation) STD.1TI.J-T RECflN E.350-ENGL ZOO 4862573 Ob7Lbbb TLT I ITU-T E-SERIES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS 3PERATION, NUMBERING, ROUTING AND MOBILE SERVICES NTERNAT
3、IONAL 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 service an
4、d public land mobile service 3PERATIONAL 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 NON- TE
5、LEPHONY APPLICATIONS 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 Measurement an
6、d 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 TRAFFIC ENGINEERING QUA
7、LITY 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 services Use of qua
8、lity of service objectives for planning of telecommunication networks Field data collection and evaluation on the performance of equipment, networks and services E.100-E.103 E.104-E.119 E.120-E.139 E. 140-E. 159 E. 160-E. 169 E. 170-E. 179 E. 1 80-E. 1 99 E.200-E.229 E.230-E.249 E.260-E.269 E.300-E.
9、319 E.320-E.329 E.330-E.399 E.400-E.409 E.410-E.419 E.420-E.489 E.490-E.505 E.506-E.509 E.51 0-E.519 E S20-E. 539 E S40-E .599 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 re information flows required for dynamic routin
10、g interworking between exchanges; and several examples of interworking between different dynamic routing methods. Source ITU-T Recommendation E.350 was prepared by ITU-T Study Group 2 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on 13 March 2000. STD-ITU-T RECMN E-350-ENGL
11、2000 E 48b259L Ob71bbA 892 E FOREWORD (International Telecommunication Union) is the United Nations Specialized Agency in the fie- of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The IT-T is responsible for studying technical, operatin
12、g 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 Study Groups which, in their tur
13、n, 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 are prepared on a collaborative ba
14、sis 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 ITU draws attention to the possibility that the practice or implementatio
15、n 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 asserted by members or others outside of the Recommendation development process. As of
16、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 cautioned that this may not represent the latest information and are therefore strongly urged
17、 to consult the TSB patent database. o 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 microfilm, without permission in writing from the ITU. 1 2 3 4 5 6 6.1 6.2 6.3 6.4 7 7.1 7.2 7.
18、3 7.4 8 8.1 8.2 Annex A . Dynamic routing functional models A . 1 Dynamic Non-hierarchical Routing (DNHR) functional model A.2 Dynamically Controlled Routing (DCR) functional model . A.3 Worldwide Intelligent Network (WIN) dynamic routing functional model . A.4 Real-Time Network Routing (RTNR) funct
19、ional model AS Dynamic Alternate Routing (DAR) functional model . A.6 State- and Time-Dependent Routing (STR) functional model . A.7 Distributed Adaptive Dynamic Routing (DADR) functional model A.7.1 General information about DADR A.7.2 Description of the DADR functional model (Figure A.7) Introduct
20、ion Scope References Definitions Abbreviations . Routing methods . Fixed Routing (FR) . Time-Dependent Routing (TDR) State-Dependent Routing (SDR) Event-Dependent Routing (EDR) . Interworking of different routing methods . General interworking requirements for non-hierarchical routing in meshed netw
21、orks . 7.1.1 Two-link routing . 7.1.2 Interworking with selective circuit reservation . 7.1.3 Interworking with automatic rerouting (Crankback) . Interworking of a dynamic routing method with fixed routing Interworking of different dynamic routing methods Multiple step dynamic routing for calls trav
22、ersing multiple networks . 7.4.1 Internetwork E uses a Mixed Dynamic Routing (MXDR) method 7.4.2 Internetwork E uses a single dynamic routing method . Information exchange needs . Call control information . Routing table design information . m Page 1 1 2 2 3 4 4 5 5 6 7 7 7 8 9 9 11 12 12 14 15 15 1
23、5 16 16 19 21 23 25 27 29 29 30 STD.1TU-T RECON E.350-ENGL 2000 4b2591 Ob71670 440 Page A.8 Optimized Dynamic Routing (ODR) Functional Model 33 Annex B - Information exchange examples 36 36 B. 1 B.2 Examples of routing table design information . 36 Examples of call control information . B.3 Examples
24、 of information exchange 37 B.3.1 Examples of call control information exchange 37 B.3.2 Examples of routing table design information exchange 39 B.4 Example information flows for interworking dynamic routing methods . 40 Recommendation E.350 DYNAMIC ROUTING INTERWORKING (Geneva, 2000) 1 Introductio
25、n There are many operators who have implemented a dynamic routing method in their domestic network and international network. The dynamic routing methods in use are variants of time-dependent routing (TDR), state-dependent routing (SDR), and event-dependent routing (EDR) methods. An international or
26、 inter-operator call will traverse more than one network, and hence may be routed end-to-end using more than one routing method. In the interconnecting network, different dynamic routing methods in conjunction with fixed routing may be in use. This Recommendation covers the interworking of different
27、 types of routing methods in non-hierarchical networks, in order to complete a call originating in one switch and terminating in another, where the originating, via, and terminating switches may have implemented different routing methods. Substantial improvements in telephone network cost efficiency
28、 and robustness result from the introduction of dynamic routing. Dynamic routing envisions that routing decisions adapt to load and network conditions, and that distributed, originating switch call control can be used. Dynamic routing methods may incorporate existing traffic routing features such as
29、 automatic rerouting and existing network management features such as circuit reservation. Dynamic routing methods must interwork with existing routing methods such as fixed routing. A framework is needed to guarantee unrestricted interworking of different dynamic routing methods, perhaps implemente
30、d on different vendor equipment, for routing between network operators, national as well as international. Standardization of information flows is needed, so that switching equipment from all different vendors can interwork to implement dynamic routing methods in a coordinated fashion. Hierarchical
31、routing is in widespread use throughout the world for national networks, private networks, and international networks interconnecting national networks. Studies have shown that significant economic and service benefits may accrue from implementing dynamic routing methods in national, private, or int
32、ernational networks, depending on the network structure and degree of connectivity of the network. It is desirable that a maximal set of dynamic routing techniques be enabled, which should include all dynamic routing methods in use in public networks today. All currently implemented and new dynamic
33、routing methods of PSTNASDN networks should be supported by this approach, which include distributed adaptive dynamic routing (DADR), dynamic alternate routing (DAR), dynamically controlled routing (DCR), dynamic non-hierarchical routing (DNHR), optimized dynamic routing (ODR), real-time network rou
34、ting (RTNR), state- and time-dependent routing (STR), and worldwide intelligent network (WDT) dynamic routing. 2 Scope This Recommendation gives a fiamework for dynamic routing interworking in circuit-switched PSTN, narrow-band ISDN, and broadband ISDN networks. It illustrates the functionality for
35、setting up a call from an originating exchange in one network to a destination exchange in another network, using one or more dynamic routing methods in conjunction possibly with fixed routing. It describes: a) b) c) relevant dynamic routing functions for TDR, SDR, and EDR networks; information flow
36、s required for dynamic routing interworking between exchanges; and several examples of interworking between different dynamic routing methods. STD*ITU-7 RECMN E.350-ENGL 2000 4862593 Ob73672 233 W This Recommendation is trying to enable any routing method to be implemented by a network operator and
37、interwork with other different routing methods in various exchanges. As such, the Recommendation is not tryrng to standardize any particular routing method. For those information flows requiring information exchange specific for dynamic routing, the information exchange needs are identified. 3 Refer
38、ences The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all
39、users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - - - CCITT Recommendation E. 170 (1 992), Tr
40、afic routing. ITU-T Recommendation E. 177 (1 996), B-ISDN routing. ITU-T Recommendation E.35 1 (2000), Routing of multimedia connections across TDM-, ATM- and IP-based networks. ITU-T Recommendation E.411 (1 998), International network management - Operational guidance. ITU-T Recommendation E.412 (1
41、 998), Network management controls. ITU-T Recommendation 4.71 (1993), ISDN circuit mode switched bearer services. - - - 4 Defmitions This Recommendation defines the following terms: 4.1 4.2 group for evaluation by a routing table. Circuit group: A group of circuits which is engineered as a unit. Cir
42、cuit group classmark: A data item assigned administratively at an exchange to a circuit 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.1 1 Destination exchange: Terminating exchange within a given dynamic routing network. Exchange: A switching centre. O-D pair: An originating exchange to destination exchange pa
43、ir for a given traffic stream. Originating exchange: Originating exchange within a given dynamic routing network. Route: A concatenation of circuit groups providing a connection between an O-D pair. Route set: A set of routes connecting the same O-D pair. Routing table: A route set and rules to sele
44、ct one route out of the set for a traffic stream. Traffic stream: A class of calls with the same traffic characteristics. Via exchange: A via exchange within a given dynamic routing network. STD*ITU-T RECMN E-350-ENGL 2000 I 4862591, 0673b73 L5T m 5 Abbreviations mis Recommendation uses the followin
45、g abbreviations: AAR ARR B-ISDN CB CCS CP-SDR CR DADR DAR DCR DC-SDR DE DNHR DP-SDR EDR FR GOS LLR N-ISDN ODR OE PNNI PSTN RECOM RES RP RTNR SDR STR TDR VE VDL WIN Automatic Alternate Routing Automatic Rerouting Broadband Integrated Services Digital Network Crankback Common Channel Signalling Centra
46、lized Periodic State-Dependent Routing Circuit Reservation Distributed Adaptive Dynamic Routing Dynamic Alternate Routing Dynamically Controlled Routing Distributed Call-by-Call State-Dependent Routing Destination Exchange Dynamic Non-hierarchical Routing Distributed Periodic State-Dependent Routing
47、 Event-Dependent Routing Fixed Routing Grade of Service Least Loaded Routing Narrow-band Integrated Services Digital Network Optimized Dynamic Routing Originating Exchange Private Network-to-Network Interface Public Switched Telephone Network recommendation Reservation Routing Processor Real-Time Ne
48、twork Routing State-Dependent Routing State- and Time-Dependent Routing Time-Dependent Routing Via Exchange Via and Destination Exchange List Worldwide Intelligent Network (Routing) STD.ITU-T RECflN E.350-ENGL 2000 46b2591 0b73b74 6 Routing methods A specific traffic routing method is characterized
49、by the structure of the routing table used in the method. The routing table consists of a route set and rules to select one route out of the route set for a given traffic stream. When a call in a traffic stream arrives at its originating exchange (OE), the OE implementing the routing method executes the route selection rules associated with the routing table for the call to determine a route among the routes in the route set for the traffic stream. In a routing method, the set of routes that can be assigned to the call stream may be altered according to a certain route set alterat
