1、 International Telecommunication Union ITU-T X.85/Y.1321TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Corrigendum 1(06/2005) SERIES X: DATA NETWORKS, OPEN SYSTEM COMMUNICATIONS AND SECURITY Public data networks Transmission, signalling and switching SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INT
2、ERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Transport IP over SDH using LAPS Corrigendum 1 ITU-T Recommendation X.85/Y.1321 (2001) Corrigendum 1 ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS, OPEN SYSTEM COMMUNICATIONS AND SECURITY PUBLIC DATA NETWORKS Services and f
3、acilities X.1X.19 Interfaces X.20X.49 Transmission, signalling and switching X.50X.89 Network aspects X.90X.149 Maintenance X.150X.179 Administrative arrangements X.180X.199 OPEN SYSTEMS INTERCONNECTION Model and notation X.200X.209 Service definitions X.210X.219 Connection-mode protocol specificati
4、ons X.220X.229 Connectionless-mode protocol specifications X.230X.239 PICS proformas X.240X.259 Protocol Identification X.260X.269 Security Protocols X.270X.279 Layer Managed Objects X.280X.289 Conformance testing X.290X.299 INTERWORKING BETWEEN NETWORKS General X.300X.349 Satellite data transmissio
5、n systems X.350X.369 IP-based networks X.370X.379 MESSAGE HANDLING SYSTEMS X.400X.499DIRECTORY X.500X.599 OSI NETWORKING AND SYSTEM ASPECTS Networking X.600X.629 Efficiency X.630X.639 Quality of service X.640X.649 Naming, Addressing and Registration X.650X.679 Abstract Syntax Notation One (ASN.1) X.
6、680X.699 OSI MANAGEMENT Systems Management framework and architecture X.700X.709 Management Communication Service and Protocol X.710X.719 Structure of Management Information X.720X.729 Management functions and ODMA functions X.730X.799 SECURITY X.800X.849 OSI APPLICATIONS Commitment, Concurrency and
7、 Recovery X.850X.859 Transaction processing X.860X.879 Remote operations X.880X.889 Generic applications of ASN.1 X.890X.899 OPEN DISTRIBUTED PROCESSING X.900X.999 TELECOMMUNICATION SECURITY X.1000 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. X.85/Y.1321 (2001)/
8、Cor.1 (06/2005) i ITU-T Recommendation X.85/Y.1321 IP over SDH using LAPS Corrigendum 1 Summary This corrigendum to ITU-T Rec. X.85/Y.1321 specifies a revision of the computation of 32/16-bit FCS. Source Corrigendum 1 to ITU-T Recommendation X.85/Y.1321 (2001) was approved on 29 June 2005 by ITU-T S
9、tudy Group 15 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. X.85/Y.1321 (2001)/Cor.1 (06/2005) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sec
10、tor (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 standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets ever
11、y 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 covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview
12、, 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 indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is volunta
13、ry. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the ne
14、gative 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 PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the
15、 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 development process. As of the date of approval of this Recommendat
16、ion, ITU had/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 to consult the TSB patent database. ITU
17、 2005 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. X.85/Y.1321 (2001)/Cor.1 (06/2005) iii CONTENTS Page 1) Clause A.2.7: Frame Check Sequence (FCS) field. 1 ITU-T Rec. X.85/Y.1321 (2001)/Cor.1 (06
18、/2005) 1 ITU-T Recommendation X.85/Y.1321 IP over SDH using LAPS Corrigendum 1 1) Clause A.2.7: Frame Check Sequence (FCS) field Modify clause A.2.7 as follow: The FCS field shall be a 32-bit sequence. It shall be the ones complement of the sum (modulo 2) of: the remainder of xm(x31+ x30+ . + x + 1)
19、 divided (modulo 2) by the generating polynomial, where m is the number of bits of the information over which the CRC is calculated; and the remainder of the division (modulo 2) by the generating polynomial of the product of x32by the information over which the CRC is calculated. The 32-bit FCS gene
20、rating polynomial is: G(x) = x32+ x26+ x23+ x22+ x16+ x12+ x11+ x10+ x8+ x7+ x5+ x4+ x2+ x + 1 The result of the CRC calculation is placed with the least significant bit right justified in the FCS field. As a typical implementation at the transmitter, the initial content of the register of the devic
21、e computing the remainder of the division is preset to all “1“s and is then modified by division by the generating polynomial (as described above) on the address, control, SAPI and information fields over which the CRC is to be calculated; the ones complement of the resulting remainder is put into t
22、he 32-bit FCS field. As a typical implementation at the receiver, the initial content of the register of the device computing the remainder of the division is preset to all “1“s. The final remainder, after multiplication by x32and then division (modulo 2) by the generating polynomial of the serial i
23、ncoming protected bits and FCS, shall be (in the absence of errors): C(x) = x31+ x30+ x26+ x25+ x24+ x18+ x15+ x14+ x12+ x11+ x10+ x8+ x6+ x5+ x4+x3+ x + 1 For compatibility with RFC 2615, The the computation of 32-bit FCS and 16-bit FCS is referred to carried out according to RFC 2615 for compatibi
24、lity with RFC 2615. In theis case of 16-bit FCS, the length of FCS is changed to the two octets in Figures A.1 and A.4. ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Servic
25、es, applications and middleware Y.200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.499 Numbering, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Servic
26、es and applications Y.1100Y.1199 Architecture, access, network capabilities and resource management Y.1200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Cha
27、rging Y.1800Y.1899 NEXT GENERATION NETWORKS Frameworks and functional architecture models Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y
28、.2299 Numbering, naming and addressing Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 For further details, please refer to the list of ITU-T Recommendations. Printed in Switzerland Geneva,
29、2005 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, dig
30、ital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and pro
31、tection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone transmission q
32、uality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
