1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU G.803 (03/2000) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital transmission systems - Digital networks - General aspects Architecture of transport networks based on the synchro
2、nous digital hierarchy (SDH) ITU-T Recommendation G.803 (Formerly CCITT Recommendation) STD-ITU-T RECMN G-BOI-ENGL ZOOO 48b2592 ObB8312 335 9 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G. 10043. 199 GEN
3、ERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER- TRANSMISSION SYSTEMS G.200-G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES GENEML CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE METALLIC LINES TERMINAL EQUIPMENTS G.700-G.799 DIGITAL NETWORKS G.80
4、0-G.899 G.300-G.399 G.400-G.449 SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH Design objectives for digital networks Quality and availability targets Network capabilities and functions SDH network characteristics Management of transport network SDH radio and satellite systems in
5、tegration Optical transport networks DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.8 1 0-G.8 19 G.820-G.829 G.830-G.839 G.840-G.849 G.850-G.859 G.86M.869 G.870-G.879 G.90ffi.999 For further details, please refer to the list of ITU-T Recommendations. STD-ITU-T RECMN G.803-ENGL 2000 4862593 0686333 273 I
6、TU-T Recommendation G.803 Architecture of transport networks based on the synchronous digital hierarchy (SDH) Summary This ITU-T Recommendation describes the functional architecture of transport networks including network synchronization principles for networks that are based on the SDH. This ITU-T
7、Recommendation uses the architectural description defined in ITU-T Recommendation G.805, the generic functional architecture of transport networks. The application of various mappings is also included. Source ITU-T Recommendation G.803 was revised by ITU-T Study Group 13 (1997-2000) and approved und
8、er the WTSC Resolution 1 procedure on 10 March 2000. STD=ITU-T RECMN G-803-ENGL 2000 4862571 0688314 208 FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a
9、 permanent organ of ITU. IT-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 years, e
10、stablishes 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 information technology which fall within IT-Ts purview, the necessary
11、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 RIGHTS ITU draws attention to the possib
12、ility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. IT takes no position concming the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recom
13、mendation development process. As of the date of approval of this Recommendation, U 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 a
14、nd are therefore strongly urged to consult the TSB patent database. I o ITU 2001 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
15、 3 4 5 5.1 5.2 5.3 6 6.1 6.2 6.3 7 7.1 7.2 8 8.1 8.2 8.3 STDeITU-T RECflN G.BO3-ENGL 2000 48b2593 Ob88335 044 CONTENTS Scope References Terms and definitions . Abbreviations . Application of the G.805 layering concept . Multiplexing of multiple clients . Support of ATM over SDH Concatenation . 5.3.1
16、 Contiguous concatenation . 5.3.2 Virtual concatenation 5.3.3 Interworking between contiguous and virtual concatenation Connection supervision Inherent monitoring Non-intrusive monitoring . Sublayer monitoring . SDH transport network availability enhancement techniques SDH multiplex section protecti
17、on 7.1.1 SDH multiplex section 1+1 protection 7.1.2 SDH multiplex section 1 :N protection 7.1.3 SDH multiplex section shared protection rings . 7.1.4 SDH multiplex section dedicated rings . SDH subnetwork connection protection examples . Architecture of synchronization networks Introduction Synchron
18、ization network aspects . 8.2.1 Synchronization methods 8.2.2 Synchronization network architecture . 8.2.3 Synchronization modes . Synchronization network reference chain . 8.2.5 Synchronization strategy . 8.2.4 8.2.6 Synchronization network evolution 8.2.7 Synchronization network robustness . Paylo
19、ad jitter and wander . 8.3.1 8.3.2 SDH network model for pointer activity simulation . Jitter at a SDWPDH boundary 1 1 2 3 3 5 6 7 7 7 10 11 11 11 11 16 16 16 16 16 16 17 17 17 17 17 18 22 23 25 25 25 26 27 27 . STD.ITU-T RECMN G.O3-ENGL 2000 486259L 0688316 TBO m 8.4 PDH/SDH interworking implicatio
20、ns . 9 Selection of a primary rate mapping . Appendix I . Client server associations of SDH layer networks Appendix II . Introduction of SDH-based transport networks Types of client layer signals . 11.1 General . 11.2 11.2.1 SDH case . 11.2.2 PDH case . 11.3 11.4 Initial introduction of SDH-based eq
21、uipment Interworking between PDH- and SDH-based transport networks 11.4.1 Interworking levels 11.4.2 SDH overlay 11.4.3 SDH DXC/ADMs . 11.4.4 SDH line systems Introduction of STM-N interfaces on 64 kbit/s switches (and DXCs) . Appendix III - Guidelines for synchronization network engineering . 11.5
22、III . 1 111.2 III . 3 111.4 111.5 111.6 III . 7 111.8 111.9 Introduction Purpose of the synchronization network Requirements for synchronization networks Analysis of synchronization networks PRC-Level options . SSU-Level solutions . 111.6.1 Checking reference provisionings at the SSU-Level 111.6.2 A
23、bsolute fkequency offset guarding SEC-Level solutions . 111.7.1 Application of the SSM protocol in the SSU-Level 111.7.2 Examples of SEC subnetworks with SSM parameters Synthesis of the synchronization network Definitions used in Appendix III Page 28 29 29 31 31 32 32 32 33 33 33 34 34 34 35 37 37 3
24、7 38 39 41 42 43 45 46 47 47 51 52 STD.ITU-T RECMN G.BO3-ENGL 2000 4862593 0688337 917 m ITU-T Recommendation G.803 Architecture of transport networks based on the synchronous digital hierarchy (SDH) 1 Scope This ITU-T Recommendation describes the functional architecture of transport networks includ
25、ing network synchronization principles for networks that are based on the SDH. This ITU-T Recommendation uses the architectural description defined in ITU-T Recommendation G. 805, the generic functional architecture of transport networks. The application of various mappings is also included. 2 Refer
26、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
27、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 G.702 (1988), Digita
28、l hierarchy bit rates. CCITT Recommendation G.703 (1 991), Physical/electrical characteristics of hierarchical digital interfaces. ITU-T Recommendation G.704 (1 999, Synchronous pame structures used at 1544, 6312, 2048, 8488 and 44 736 kbith hierarchical levels. ITU-T Recommendation G.707 (1996), Ne
29、twork node inteflace for the Synchronous Digital Hierarchy (SDH). CCITT Recommendation G.774 (1992), Synchronous Digital Hierarchy (SDH) management information model for the network element vim. ITU-T Recommendation G.783 (1 997), Characteristics of Synchronous Digital Hierarchy (SDH) equipment finc
30、tional blocks. - ITU-T Recommendation G.805 (1 999, Generic functional architecture of transport networks. ITU-T Recommendation G.8 1 O (1 996), Definitions and terminology for synchronization networks. CCITT Recommendation G.811 (1988), Timing requirements at the outputs of primary reference clocks
31、 suitable for plesiochronous operation of international digital links. - - - - - - - CCITT Recommendation G.812 (1988), Timing requirements at the outputs of slave clocks suitable for plesiochronous operation of international digital links. ITU-T Recommendation G.8 13 (1 996), Timing characteristics
32、 of SDH equipment slave clocks (SEC). CCITT Recommendation G.822 (1 988), Controlled slip rate objectives on an international digital connection. - ITU-T Recommendation G.823 (1993), The control of jitter and wander within digital networks which are based on the 2048 kbit/s hierarchy. STD-ITU-T RECM
33、N G-BO3-ENGL 2000 M 4Bb259L ObBB3LB 853 m ITU-T Recommendation G.824 (1993), The control of jitter and wander within digitai networks which are based on the 1544 kbitls hierarchy. ITU-T Recommendation G.832 (1995), Transport of SDH elements on PDH networks - Frame and multiplexing structures. - ITU-
34、T Recommendation G.841 (1999, Types and characteristics of SDH network protection architectures. ITU-T Recommendation G.964 (1994), V-Interfaces at the digital Local Exchange (LE) - V5.1 Inte$ace (based on 2048 kbit/s) for the support of Access Network (AN). ITU-T Recommendation G.965 (1995), V-lnte
35、gaces at the digital Local Exchange (LE) - V5.2 Interface (based on 2048 kbith) for the support of Access Network (AN). ITU-T Recommendation 1.326 (1 999, Functional architecture of transport networks based on ATM. - - - - - 3 Terms and definitions This ITU-T Recommendation uses the terminology defi
36、ned in ITU-T Recommendations G.783 , G.805 and G.841; the following terms are specific to this ITU-T Recommendation. The layer networks defined below terminate and generate the overheads defined in ITU-T Recommendation G.707. 3.1 SDH higher-order path layer networks: Those layer networks with charac
37、teristic information of VC-31, VC-3-Xv (X = 2 . 48)2, VC-4, VC-4-Xc (X = 4, 16)3 or VC-4-Xv (X=2 . 16)3. 3.2 SDH lower-order path layer networks: Those layer networks with characteristic information of VC-11, VC-1 1-Xv (X = 2 . . . 84), VC-12, VC-12-Xv (X = 2 . . . 63), VC-2, VC-2-Xc (X = 2 . . . 7)
38、4, VC-2-Xv (X = 2 . . . 21)s or VC-31 or VC-3-Xv (X = 2 . . . 3)s. 3.3 SDH path layer: A transport assembly composed of the SDH higher-order path layer network and lower-order path layer network together with the associated adaptation functions. 3.4 SDH section layer: A transport assembly composed o
39、f the SDH multiplex section layer network and regenerator section layer network together with the associated adaptation functions. 3.5 SDH multiplex section layer: A layer network with characteristic information of STM-N, Le. with a bit rate of STM-N and the multiplex section overhead as defined in
40、ITU-T Recommendation G.707. 3.6 SDH regenerator section layer: A layer network with characteristic information of STM-N, i.e. with a bit rate of STM-N and the regenerator section overhead as defined in ITU-T Recommendation G.707. The VC-3 is considered to be a higher-order path if it is supported di
41、rectly by an AU-3 in a multiplex section layer network; it is considered a lower-order path if it is supported by a Tu-3 in a VC-4 layer network. 2 Values of X larger than 48 may be required. Values of X larger than 16 may be required. Transported in one higher order VC-3. Transported in one higher
42、order VC-4. STD.ITU-T RECMN G-803-ENGL ZOO0 m 4862571 0688339 797 4 Abbreviations This ITU-T Recommendation uses the following abbreviations: ADM AIS APS ATM AUG AU-n DXC HOP HOPT HOTCA HOTCT HOPM LOP MS PDH PRC PSTN RS SDH STM-N TU-n TUG-n VC-n VC-n-X VC-n-Xc VC-n-Xv VP Add/Drop Multiplex Alarm Ind
43、ication Signal Automatic Protection Switching Asynchronous Transfer Mode Administrative Unit Group Administrative Unit (level) n Digital Cross-Connect Higher-Order Path Higher-Order Path Termination Higher-Order Tandem Connection Adaptation Higher-Order Tandem Connection Termination Higher-Order Pat
44、h Matrix Lower-Order Path Multiplex Section Plesiochronous Digital Hierarchy Primary Reference Clock Public Switched Telephone Network Regenerator Section Synchronous Digital Hierarchy Synchronous Transport Module (level) N Tributary Unit (level) n Tributary Unit Group (level) n Virtual Container (l
45、evel) n Concatenation of X virtual containers (of level n) Contiguous concatenation of X virtual containers (of level n) Virtual concatenation of X virtual containers (of level n) ATM virtual path 5 The functional architecture of SDH transport networks is described using the generic rules defined in
46、 ITU-T Recommendation G.805. The specific aspects regarding the characteristic information, clienuserver associations, the topology, the connection supervision and protection switching of SDH transport networks are provided in this XTU-T Recommendation. This ITU-T Recommendation uses the terminology
47、 and functional architecture and diagrammatic conventions defined in ITU-T Recommendation G.805. Application of the 6.805 layering concept STD-ITU-T RECMN G-803-ENGL 2000 48b259L Ob88320 401 A transport network based on the SDH can be decomposed into a number of independent transport layer networks
48、with a clienthewer association between adjacent layer networks. Each layer network can be separately partitioned in a way which reflects the internal structure of that layer network or the way that it will be managed. The structure of the SDH layer networks and the adaptation functions is shown in F
49、igure 5-1. AP HOPA HOPT LOPA LOPT MSA MST NC RSA RST TCP source LOPT source LOPAT- LOP AP LOPA sink LOP AP LOW sink LOP trail -_ LOP NC _- LOP TCP T1308670-96 Access Point Higher-Order Path Adaptation Higher-Order Path Termination Lower-Order Path Adaptation Lower-Order Path Termination Multiplex Section Adaptation Mutiplex Section Termination Network Connection Regenerator Section Adaptation Regenerator Section Termination Termination Connection Point Figure 5-1/G.803 - SDH layer networks and adaptation functions STD-ITU-T RECMN G.803-ENGL 2000 48b259L Ob88321 348
