1、 International Telecommunication Union ITU-T L.72TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2008) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT Databases for optical access network infrastructure ITU-T Recommendation L.72 ITU-T Rec. L.72 (
2、01/2008) i ITU-T Recommendation L.72 Databases for optical access network infrastructure Summary ITU-T Recommendation L.72 deals with the configuration and functions of databases for the optical access network infrastructure to be used in the design, maintenance, operation and administration of opti
3、cal access networks. Source ITU-T Recommendation L.72 was approved on 8 January 2008 by ITU-T Study Group 6 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. L.72 (01/2008) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the
4、field of telecommunications, information and communication technologies (ICTs). 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 standar
5、dizing telecommunications on a worldwide basis. The World Telecommunication 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 cove
6、red by the procedure laid down in WTSA Resolution 1. In some areas of information 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 indic
7、ate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved
8、when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROP
9、ERTY 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 Rights, whether assert
10、ed 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, implementers are cautioned th
11、at this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2008 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU
12、-T Rec. L.72 (01/2008) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms and definitions . 1 4 Abbreviations and acronyms 2 5 Database configuration . 2 6 Database functions 2 6.1 Basic functions . 3 6.2 Reliability . 3 6.3 Extension 4 6.4 Security. 4 6.5 Compatibility 4 Appendix I Japanese experi
13、ence. 5 I.1 Database structure 5 I.2 When using a passive optical network (PON) system 6 I.3 When branching optical fibre cable 8 iv ITU-T Rec. L.72 (01/2008) Introduction Progress on communication technologies has led to the active development of many kinds of broadband service such as voice, data
14、and video communication using access networks. It is important to realize high-speed broadband networks to provide such services economically. In order to provide these services in a timely way, we must construct optical access networks. In addition, there will be a huge expansion of the optical acc
15、ess network infrastructure, including optical fibre and optical fibre cable, as the number of customers increases. Therefore, databases for the optical access network infrastructure for network design, maintenance, operation and administration is important and should be considered. ITU-T Rec. L.72 (
16、01/2008) 1 ITU-T Recommendation L.72 Databases for optical access network infrastructure 1 Scope This Recommendation describes the configuration and functions of databases for the optical access network infrastructure to be used in the design, maintenance, operation and administration of optical acc
17、ess networks. 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 other references are subj
18、ect to revision; 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. The reference to a document
19、within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.694.1 ITU-T Recommendation G.694.1 (2002), Spectral grids for WDM applications: DWDM frequency grid. ITU-T G.694.2 ITU-T Recommendation G.694.2 (2002), Spectral grids for WDM applications:
20、 CWDM wavelength grid. ITU-T G.983.1 ITU-T Recommendation G.983.1 (2005), Broadband optical access systems based on Passive Optical Networks (PON). ITU-T G.983.2 ITU-T Recommendation G.983.2 (2005), ONT management and control interface specification for B-PON. ITU-T G.983.3 ITU-T Recommendation G.98
21、3.3 (2001), A broadband optical access system with increased service capability by wavelength allocation. ITU-T G.983.4 ITU-T Recommendation G.983.4 (2001), A broadband optical access system with increased service capability using dynamic bandwidth assignment. ITU-T G.983.5 ITU-T Recommendation G.98
22、3.5 (2002), A broadband optical access system with enhanced survivability. ITU-T G.984.1 ITU-T Recommendation G.984.1 (2003), Gigabit-capable Passive Optical Networks (G-PON): General characteristics. 3 Terms and definitions This Recommendation defines the following terms: 3.1 cluster: A system cons
23、isting of several servers that can take over a job or application from the other servers when trouble occurs. 3.2 load balancer: Equipment for the management and load distribution of an access request from outside that enables forwarding to another server. 2 ITU-T Rec. L.72 (01/2008) 4 Abbreviations
24、 and acronyms This Recommendation uses the following abbreviations and acronyms: FTTB Fibre to the Building FTTC Fibre to the Curb FTTH Fibre to the Home FTTx Fibre to the x (C: Curb, O: Office, B: Building, N: Node, P: Premises, H: Home) ID Identification LAN Local Area Network OLT Optical Line Ter
25、minal ONU Optical Network Unit QR Quick Response RFID Radio Frequency Identification 5 Database configuration There will be a huge expansion of the optical access network infrastructure as the number of customers increases. Therefore, it is very important that the database for the optical access net
26、work infrastructure for FTTx, including outside plants (e.g., optical fibres, optical fibre cables, closures, manholes, poles) be used easily for the design, maintenance, operation and administration of access networks. Moreover, the database may include data for the physical and logical optical fib
27、re line between OLTs and ONUs. The data for the database described in this Recommendation includes the above. The database for access networks contains several kinds of data including those for maps and symbols indicating places and outside plant, respectively. There is some relation between these k
28、inds of data and they should not be contradictory. Efficient operation cannot be achieved if each kind of data is managed individually. For example, if one kind of data is updated, all the linked data must be updated individually. Therefore, an integrated database should be constructed and all linke
29、d data should be updated simultaneously to reduce the maintenance and management of database operation. When the access network database is designed and constructed, it should be systematized to operate stably as the managed data increase. When systematizing the database, the following main items sh
30、ould be considered: 1) Common data that are managed universally, such as the coordinate data on maps, should be separated from other data and managed efficiently to prevent overlapping data management. 2) Universal data, such as physical plant data, should not depend on changeable data that are prov
31、ided for a plants convenience such as plant name and plant number. Therefore, it is desirable for the universal data and changeable data to be separated and stored in different tables. 3) It is desirable for complementary data, which explain the main data, to be separated and stored in different tab
32、les. 6 Database functions The following should be considered when a database for the optical access network infrastructure is constructed. ITU-T Rec. L.72 (01/2008) 3 6.1 Basic functions 6.1.1 Database contents and structure The database contents (e.g., data items, data format, data fields) and soft
33、ware should first be determined when a database for the optical access network infrastructure is designed based on the database requirements which are made taking into account the optical fibre network configuration (point-to-point network, ring network and/or point-to-multipoint network), optical s
34、ystem (e.g., CWDM, DWDM), maintenance method, etc. In addition, it is necessary to link efficiently between many kinds of data without any contradictions in the database. Therefore, the database structure should be determined so that it links efficiently between many kinds of data without contradict
35、ion. For example, it should be possible to link efficiently without contradiction by using a database structure in which the outside plant for access networks are separated and managed in several layers. 6.1.2 Data input, deletion and updating In general, the database should have data input, deletio
36、n, update, reference and retrieval functions. In addition, easy methods for input, deletion and update using, for example, QR cords and RFID tags should be considered. The data should always be up-to-date. Therefore, a data maintenance procedure should be determined. Moreover, a data checking proced
37、ure or system will also be needed on the assumption that there will be data input errors. In addition, the effective use of the existing database should be taken into consideration. For example, it should display a cable route visibly and easily on a map by using the existing digital map database su
38、ch as the database for a car navigation system. 6.1.3 Network construction for database access In order to access the database from different departments and input, delete, update and/or refer to data when the access network is designed, maintained and operated, it is necessary to construct a networ
39、k for database access that connects between the database server and client terminal. 6.2 Reliability It is important to improve the database reliability to reduce the time needed to link the access network to a customer and to ensure efficient network maintenance when the demand for optical access n
40、etworks increases. The following items should be considered. 6.2.1 Reliability of the database system The database system consists of servers, data storage and networks, client terminals, etc. The server load should be dispersed using a load balancer controlled by middleware, clusters, and/or multi-
41、task systems. Moreover, two or more data storage systems should be used and each system should store the same data as a backup in case of damage. A network configuration such as a ring network should be selected for database access to improve reliability. In addition, a system recovery procedure and
42、 system recovery target time should be determined for use when the database system experiences trouble. 6.2.2 Backup To improve database reliability and to avoid interferring with the design, maintenance and operation when data are accidentally deleted and/or the hardware is broken, a data backup an
43、d recovery system should be provided. 4 ITU-T Rec. L.72 (01/2008) 6.3 Extension There should be a function or data field that allows data to be added as required for the growing access network infrastructure and/or the upgrading of an optical access network when the required transmission capacity, t
44、ransmission length and/or number of customers increase (e.g., change point-to-point network to PON) in the future. 6.4 Security Those responsible for design, maintenance, operation and administration should be able to access the database easily, but unauthorized access should be prevented to avoid d
45、ata draining or destruction. In particular, it is necessary to achieve sufficient database security when several people have access to the database using, for example, a LAN and/or the Internet, to prevent data draining or destruction as the result of illegal access and/or cyber terror. In addition,
46、 it is important to provide virus protection for a database that is connected, for example, to a LAN or the Internet. 6.4.1 Virus protection It is necessary to protect against viruses using anti-virus software or a special closed network for a database that is not connected to a public network such
47、as the Internet. 6.4.2 Account management It is necessary to access the database using an account. Moreover, the database should have addition, deletion and correction functions to keep the account updated. 6.4.3 Log recording The access and system log should be recorded to make it possible to inves
48、tigate the cause and provide a countermeasure when serious trouble or an accident occurs. 6.5 Compatibility The databases of different countries or telecommunication companies may not be compatible. This is because each database is used for the design, maintenance, operation and administration of op
49、tical access networks in individual telecommunication company or country. If necessary, the database contents should be determined so that they can negotiate with each other. ITU-T Rec. L.72 (01/2008) 5 Appendix I Japanese experience (This appendix does not form an integral part of this Recommendation) I.1 Database structure It is necessary to link between many kinds of data in the database. Therefore, a database structure with several layers is employed in Japan to make it possible to link efficiently between many kinds of data without any contradictions. Figure I.1 and
