1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU G.831 (03/2000) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital networks - Network capabilities and functions Management capabilities of transport networks based on the synchron
2、ous digital hierarchy (SD“ ITU-T Recommendation G.831 (Formerly CCITT Recommendation) ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL, TELEPHONE CONNECTIONS AND CIRCUITS TRANSMISSION SYSTEMS INDIVIDUAL, CHARACTERISTICS OF INTERNATIONAL, CARRI
3、ER TELEPHONE SYSTEMS ON METALLIC LINES GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER- GENERAL CHARACTERISTICS OF INTERNATIONAL, CARRIER TELEPHONE METALLIC LINES SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY TESTING EQUIP
4、MENTS TRANSMISSION MEDIA CHARACTERISTICS DIGITAL, TERMINAL, EQUIPMENTS DIGITAL, NETWORKS General aspects Design objectives for digital networks Quality and availability targets .- - Network capabilities and functions SDH network characteristics Management of transport network SDH radio and satellite
5、 systems integration Optical transport networks DIGITAL, SECTIONS AND DIGITAL, LINE SYSTEM G. 1 OM. 199 G.20M.299 G.30M.399 G.40M.449 G.45M.499 G.50M.599 G.60M.699 G.70M.799 G.80M.899 G.80M.809 G.8 1 M.8 19 G.82M.829 G.84M.849 G.85M.859 G.86M.869 G.87M.879 G.90M.999 For further details, please re$er
6、 to the list of ITD-T Recommendations. ITU-T Recommendation G.831 03/2000 08/96 03/93 Management capabilities of transport networks based on the synchronous digital hierarchy (SDH) Second revision. The API definition in clause 3 is extended with a specification of the padding character for strings l
7、ess than 15 characters. A new Appendix I covering a sectionpath trace has been added. First revision Initial version Summary This Recommendation describes the management requirements of the layered and partitioned SDH transmission networks defined in ITU-T G.803. These include the path management pr
8、ocesses and the interfacing requirements for intenvorking across administrative domain boundaries both within a single network operators network and between networks operated by different network operators. The technical details to implement these requirements will be found in other Recommendations.
9、 History and source I Recommendation history I Issue I Notes ITU-T G.831(03/2000) 1 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 permanent organ of I
10、TU. 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 years, establishes the topic
11、s 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 WTSC Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepa
12、red 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 possibility that the prac
13、tice 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 Rights, whether asserted by ITU members or others outside of the Recommendation develo
14、pment 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, implementors are cautioned that this may not represent the latest information and are therefo
15、re strongly urged to consult the TSB patent database. 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 fi-om ITU. 11 ITU-T G.831(03/2000
16、) CONTENTS 1 1.1 1.2 1.3 2 2.1 2.2 3 4 4.1 4.2 4.3 4.4 4.5 Scope . Structure of Recommendation References . Abbreviations Management capabilities Categories of management capability . Management processes of SDH networks SDH access point identification SDH trail management functions Introduction . T
17、rail Set-up 4.2.1 General path Set-up control structure . 4.2.2 Section Set-up SDH trail validation SDH trail monitoring SDH trail protection and restoration . Appendix I . Sectionpath identifier format ITU-T G.831(03/2000) 1 9 . 111 ITU-T Recommendation G.831 Management capabilities of transport ne
18、tworks based on the synchronous digital hierarchy (SDH) 1 Scope It is of prime importance for the design and operation of SDH telecommunication networks in multi-vendor, multi-technology and multi-operator environments to develop commonality of processes and parameters for management standards inclu
19、ding in-service performance management, operations and maintenance management. 1.1 Structure of Recommendation Clause 2 identifies the management capabilities of SDH. Clause 3 gives the requirements of access point identifiers and recommends a format for the identifiers. Clause 4 contains informatio
20、n on SDH trail management functions. 1.2 References 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
21、other references are subject to revision; all 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.
22、 - - - ITU-T E. 164 (1997), The international public telecommunication numberingplan. ITU-T G.707 (1996), Network node interface for the synchronous digital hierarchy (SDH). ITU-T G.774 (1 992), Synchronous digital hierarchy (SDH) management information model for the network element view. ITU-T G.78
23、4 (1 999), Synchronous digital hierarchy (SDH) management. ITU-T G.803 (2000), Architecture of transport networks based on the synchronous digital hierarchy (SDH). - ITU-T M.30 1 O (2000), Principles for a telecommunications management network. - ITU-T T.50 (1 992), International Reference Alphabet
24、(IRA) (Formerly International Alphabet No. 5 or IA5) - Information technology - 7-bit coded character set for information interchange. IS0 3166 (All Parts), Codes for the representation of names of countries and their subdivisions. - - - 1.3 Abbreviations This Recommendation uses the following abbre
25、viations: API Access Point Identifier IRA International Reference Alphabet ISDN Integrated Services Digital Network SDH Synchronous Digital Hierarchy ITU-T G.831(03/2000) 1 TMN Telecommunications Management Network VC-n Virtual Container-n VC-n-xc Virtual Container-n x times concatenated 2 Managemen
26、t capabilities 2.1 Categories of management capability The SDH will enable a greater degree of automation in the management of transmission networks and of the fabric which supports them. Management capabilities fall broadly into three categories fiom the viewpoint of standards support. These are: a
27、) Those capabilities which must be standardized to allow automated interaction between the managed networks of different network operators. b) Those capabilities which should be standardized to simpli operations within the domain of a single operator who must obtain equipment fiom different vendors.
28、 c) Those capabilities which may be defined within a single management domain to optimize operations within that domain. 2.2 This clause introduces specific management capabilities and processes for SDH transport networks: Management processes of SDH networks i) ii) iii) iv) v) vi) 2 The capability
29、to set up a path between any client access points, across any domain and across any network operator boundaries. The client will generally be another network layer but may, in the case of a leased line, be an end user. The path may be: - a point-to-point Virtual Container-n (VC-n and VC-n-xc accordi
30、ng to ITU-T G.707) path; or a branch of a point-to-multipoint connection in the path layer network realized within, e.g. satellite subnetworks; or a part of an asymmetrical connection in the path layer network. - - The path may be a full time connection or a part time connection. This capability wil
31、l have to operate to financial and time-to-deliver constraints and also be intelligent enough to ensure that it does not disrupt temporary usages of subsections such as restoration connections or even testing activities. The need for a competitive supply arrangement is left for further study. The ca
32、pability to set up a path will require access to: - - inventory control facilities. The capability to maintain the paths to a level of performance as agreed in the contract for supply of the network service. The capability to continuously monitor and record the performance of the allocated paths: a)
33、 for acceptance testing; and b) while in service to validate compliance to commitment of the required performance level. On a point-to-multipoint network, the capability to identi individual branches which are failing to meet their performance limits. Restoration actions must be activated, if a tran
34、sgression of the performance limit is detected. remote activity monitoring featwes; and ITU-T G.831(03/2000) vii) viii) ix) x) xi) 3 The management system will require the capability to communicate securely with an external network operator or special domain management system to inform them that the
35、re is a problem. The capability will be provided for simple remote maintenance of the fabric of the network including the identification and location of faulty equipment within an operator domain and at operator domain boundaries. The capability will be provided to perform directly the simple remote
36、 maintenance action of individual network elements. The capability to generate resource utilization information to provide input to the billing process both within a domain and between network operators. This information will also assist with the: - planning of routes; and - inventory control. The c
37、apability to support ancillary management functions as identified as being appropriate to SDH network management. SDH access point identification An essential requirement for successful management of SDH networks incorporating featwes such as point-to-point and point-to-multipoint paths is a unique
38、means of identifymg significant points in the network, e.g. access points. The featwes of Access Point Identifiers (APIS) are: - - each access point identifier must be globally unique in its layer network; where it may be expected that the access point may be required for path Set-up across an inter
39、-operator boundary, the access point identifier must be available to other network operators; the access point identifier should not change while the access point remains in existence; the access point identifier should be able to identi the country and network operator which is responsible for rout
40、ing to and rom the access point; the set of all access point identifiers belonging to a single administrative layer network should form a single access point identification scheme; the scheme of access point identifiers for each administrative layer network can be independent rom the scheme in any o
41、ther administrative layer network. It is recommended that the VC-11, VC-12, VC-2, VC-2-xc, VC-3, VC-4 and VC-4-xc should each have the access point identification scheme bases on a tree-like format to aid routing control search algorithms. The access point identifier should be globally unambiguous.
42、The API shall begin with either the country code as defined in ITU-T E.164 (one, two or three numeric characters) or, the three alphabetic character country code as defined in IS0 3 166. The remainder of the API characters that follow the country code shall be a matter for the organization to whom t
43、he country code has been assigned, provided that uniqueness is guaranteed. These characters may be any alphanumeric characters as defined in ITU-T T.50 (International Reference Version - 7-bit coded character set for information interchange). The alphanumeric character set consists of the characters
44、 “air to “z“, “A“ to “Z“, and “O“ to 9. In the case where the API uses less than fifteen characters, the API will be padded (extended) with the T.50 “NUL“ character to get a fifteen byte character string. - - - - ITU-T G.831(03/2000) 3 For intenvorking with equipment developed prior to this version
45、of the Recommendation that may use the T.50 space as a padding character, new equipment should be able to generate T.50 “SPACE“ padding characters as an option. A similar access and test point identification scheme is required for the section layer to support point-to-point and point-to-multipoint p
46、aths and wide area multiplexors as used in satellite subnetworks. The byte allocations for the transmission of the access point identifier at the section layer, higher-order path layer and lower-order path layer are given in ITU-T G.707. 4 SDH trail management functions 4.1 Introduction Within an SD
47、H administrative layer network, the primary management functions are to set up, validate, and monitor trails and protect or restore them if necessary. These management functions may be implemented by different subnetworks (e.g. satellite subnetwork) or in network controlled by different operators. H
48、owever, the following Recommendations ensure that these management functions work successfully in the inter-operator environment. The principle described in ITU-T G.784 for integration and intenvorking of subnetwork management systems must be adopted by all management systems. This includes the inte
49、gration of SDH systems into the generic Telecommunications Management Network (TMN). In general, each administrative path layer network is intended to be global with the possibility of establishing a trail between any two-access points in that layer. Each administrative path layer requires a significant path Set-up control system capable of working in the global, multi-operator context. In general, each administrative section layer will not require the ability to connect any one access point to any other access point as the requirement on connectivity will be restricted by the av
