1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T X.85/Y.1321TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(04/2004) SERIES X: DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS Public data networks Transmission, signalling and switching SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOC
2、OL ASPECTS AND NEXT GENERATION NETWORKS Internet protocol aspects Transport IP over SDH using LAPS Amendment 1: Bit-oriented method for LAPS ITU-T Recommendation X.85/Y.1321 (2001) Amendment 1 ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATIONS PUBLIC DATA NETWORKS Services a
3、nd facilities 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 specifi
4、cations 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 transmi
5、ssion systems X.350X.369 IP-based networks X.370X.399 MESSAGE HANDLING SYSTEMS X.400X.499 DIRECTORY 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.
6、1) X.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, Concurrenc
7、y and Recovery X.850X.859 Transaction processing X.860X.879 Remote operations X.880X.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)/Amd.1 (04/2004) i ITU-T Recommendati
8、on X.85/Y.1321 IP over SDH using LAPS Amendment 1 Bit-oriented method for LAPS Summary This amendment presents a bit-oriented method related to IP over PDH using LAPS and Ethernet over PDH (i.e., IP traffic data and Ethernet frame are transported in a PDH signal). Source Amendment 1 to ITU-T Recomme
9、ndation X.85/Y.1321 (2001) was approved on 29 April 2004 by ITU-T Study Group 17 (2001-2004) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. X.85/Y.1321 (2001)/Amd.1 (04/2004) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field o
10、f telecommunications. 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 standardizing telecommunications on a worldwide basis. The World
11、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 covered by the procedure laid down in WTSA Resolution 1. In so
12、me 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 indicate both a telecommunication administration and a recogniz
13、ed 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 when all of these mandatory provisions are met. The words
14、“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 PROPERTY RIGHTS ITU draws attention to the possibility that th
15、e 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 asserted by ITU members or others outside of the Recommendation
16、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, implementors are cautioned that this may not represent the latest information and are t
17、herefore strongly urged to consult the TSB patent database. ITU 2004 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)/Amd.1 (04/2004) iii CONTENTS Page 1) Clause 2.1.2 Other normati
18、ve references. 1 2) New Annex D . 1 ITU-T Rec. X.85/Y.1321 (2001)/Amd.1 (04/2004) 1 ITU-T Recommendation X.85/Y.1321 IP over SDH using LAPS Amendment 1 Bit-oriented method for LAPS 1) Clause 2.1.2 Other normative references Add the following references in alphanumerical order to clause 2.1.2: ITU-T
19、Recommendation G.804 (1998), ATM cell mapping into plesiochronous digital hierarchy (PDH). ITU-T Recommendation G.832 (1998), Transport of SDH elements on PDH networks Frame and multiplexing structures. ITU-T Recommendation X.86/Y.1323 (2001), Ethernet over LAPS. IETF RFC 3518 (2003), Point-to-Point
20、 Protocol (PPP) Bridging Control Protocol (BCP). IETF RFC 2472 (1998), IP Version 6 over PPP. IETF RFC 1332 (1992), The PPP Internet Protocol Control Protocol (IPCP). 2) New Annex D Add a new Annex D as follows: Annex D Bit-oriented operation The scope of this annex is located at Ethernet frame, IPv
21、4 and IPv6 over single PDH channel defined in ITU-T Rec. G.703, using bit-oriented method for LAPS. Ethernet, IPv4/v6SAP of data link layer Bit-oriented LAPSSAP of physical layerData link primitivesProtocolPhysical layer primitivesSingle PDH channelFigure D.1/X.85/Y.1321 The relationship between PDH
22、 physical layer, LAPS data link layer and upper layer 2 ITU-T Rec. X.85/Y.1321 (2001)/Amd.1 (04/2004) (It is noted that “single PDH channel“ in Figure D.1 means a pure PDH transport, or mixed PDH/SDH transport with PDH in the access and further transported via SDH in the core.) The purpose of this a
23、nnex is to provide uniform specification of Ethernet, IPv4 and IPv6 over single PDH channel on the basis of the main body of this Recommendation. This annex presents the uniform bit-oriented LAPS related to both IPv4/v6 and Ethernet over PDH channel within SDH VCs or independent PDH transmission sys
24、tem. As defined in this Recommendation, PPP operation is indicated by setting the Address Field to 0xFF. The procedures defined in RFC 1662 and associated RFCs for encapsulation of IPv4 (RFC 1332), IPv6 (RFC 2472) and Ethernet (RFC 3518) should also be used for carrying these protocols over PPP on a
25、 PDH channel. D.1 PDH channels It is also strongly recommended to use the G.703 E11/E12/E21/E22/E31/E32/E4/T12 interfaces. ITU-T Rec. G.703 specifies the digital hierarchy which shall be used to carry bit-synchronous signals, bit rates and code as follows: E11: 1544 kbit/s, code: AMI or B8ZS; E12: 2
26、048 kbit/s, code: HDB3; E21: 6312 kbit/s, code: B6ZS or B8ZS; E22: 8448 kbit/s, code: HDB3; E31: 34 368 kbit/s, code: HDB3; E32: 44 736 kbit/s, code: B3ZS; E4: 139 264 kbit/s, code: CMI. The LAPS treats an E11/E12/E21/E22/E31/E32/E4/T12 channel as bit-oriented synchronous full-duplex links in the bi
27、t-oriented case, and the associated control signals are not used for the physical layer. D.2 Operation The operation is the same as in the octet-oriented case unless otherwise noted. The opening Flag sequence, Address field, Control field, SAPI field, information field and FCS field are applied as s
28、pecified in A.2. D.2.1 Flag sequence The bit stream is examined on a bit-by-bit basis for the binary sequence 01111110 (hexadecimal 0x7e). D.2.2 Transparency Unlike the octet-oriented case, an octet stuffing procedure is not used. Instead, after FCS computation, the transmitter examines the entire f
29、rame between the two flag sequences. A “0“ bit is inserted after all sequences of five contiguous “1“ bits (including the last 5 bits of the FCS) to ensure that a flag sequence is not transmitted. In the receiving side, prior to FCS computation, any “0“ bit that directly follows five contiguous “1“
30、bits is discarded. D.2.3 Invalid frames Frames that end with a sequence of more than six “1“ bits are silently discarded, and not counted as a FCS error. D.2.4 Scrambling For consistency with existing bit-oriented implementations of HDLC, scrambling is not enabled. ITU-T Rec. X.85/Y.1321 (2001)/Amd.
31、1 (04/2004) 3 D.2.5 Rate adaptation for Ethernet over PDH If the rate adaptation is needed in the LAPS transmit processing, transmit entity adds the rate-adaptation octet(s) “0xdd“ within the frame by sending sequence(s) of 0x7d, 0xdd. This function is performed just after transparency processing an
32、d before the end flag is added. In receive direction, receive entity will remove the rate adaptation octet(s) “0xdd“ within the LAPS frame when detecting sequence(s) of 0x7d, 0xdd. This function will be done just before transparency processing and after the end flag is detected. Unlike the octet-ori
33、ented case, the functionality of the rate adaptation is not applied for Ethernet over PDH since the overhead bits are very short while Ethernet data stream is coming during the period of PDH overhead bits. The flag sequence must be transmitted during inter-frame time fill. D.3 Mapping of LAPS frames
34、 into 1544 kbit/s D.3.1 Frame format The multiframe structure for the 24-frame multiframe as described in ITU-T Rec. G.704 shall be used in this case. The LAPS frame is mapped into bits 2 to 193 (i.e., time slots 1 to 24 described in ITU-T Rec. G.704) of the 1544 kbit/s frame with the octet structur
35、e of the 1544 kbit/s frame (see Figure D.2). FF FF F F Header193 bits/125 sLAPS frame mapping field: 24 octets (TS1 TS24)Provides F3 OAM functions: Detection of loss of frame alignmentPerformance monitoring (CRC-6)Transmission of FERF and LOCPerformance reporting; ; .LAPS frame overhead Figure D.2/X
36、.85/Y.1321 Frame structure for 1544 kbit/s used to transport LAPS frames D.4 Mapping of LAPS frames into 2048 kbit/s D.4.1 Frame format The basic frame structure at 2048 kbit/s as described in ITU-T Rec. G.704 shall be used in this case. The LAPS frame is mapped into bits 9 to 128 and bits 137 to 25
37、6 (i.e., time slots 1 to 15 and time slots 17 to 31 described in ITU-T Rec. G.704) of the 2048 kbit/s frame with the octet structure of the 2048 kbit/s frame (see Figure D.3). 4 ITU-T Rec. X.85/Y.1321 (2001)/Amd.1 (04/2004) Header256 bits/125 sLAPS frameProvides F3 OAM functions: Detection of loss o
38、f frame alignment; Performance monitoring (CRC-4); Transmission of FERF and LOC; Performance reporting.HeaderTS16: Reserved for signallingTS0LAPS frame header Figure D.3/X.85/Y.1321 Frame structure for 2048 kbit/s used to transport LAPS frames D.5 Mapping of LAPS frames into 6312 kbit/s D.5.1 Frame
39、format The basic frame structure at 6312 kbit/s as described in ITU-T Rec. G.704 shall be used in this case. The LAPS is mapped into bits 1 to 768 (i.e., time slots 1 to 96 described in ITU-T Rec. G.704) of the 6312 kbit/s frame with the octet structure of the 6312 kbit/s frame. Bits 769 to 784 (tim
40、e slots 97 and 98) are reserved for user communication channels and the last five bits (F-bits) are used for frame alignment and OAM (see Figure D.4). Provides F3 OAM functions: Detection of loss of frame alignmentPerformance monitoring (CRC-5)Transmission of FERF and LOCPerformance reporting; ; .F
41、FF F FF LAPS frame mapping field: 96 octets (TS1 TS96)TS97,98: Reserved for signalling789 bits/125 sLAPS frame header Figure D.4/X.85/Y.1321 Frame structure for 6312 kbit/s used to transport LAPS frames D.6 Mapping of LAPS frames into 8448 kbit/s For further study. ITU-T Rec. X.85/Y.1321 (2001)/Amd.
42、1 (04/2004) 5 D.7 Mapping of LAPS frames into 44 736 kbit/s For further study. D.8 Mapping of LAPS frames into 34 368 kbit/s D.8.1 Frame format The basic frame structure at 34 368 kbit/s as described in ITU-T Rec. G.832 shall be used in this case. The LAPS frames are mapped into the 530 payload octe
43、ts of the 34 368 kbit/s frame with the octet structure of the 34 368 kbit/s frame (see Figure D.5). 59 octets9 rowsLAPS frameOverhead octetFigure D.5/X.85/Y.1321 Frame structure for 34 368 kbit/s used to transport LAPS frame D.9 Mapping of LAPS frames into 139 264 kbit/s D.9.1 Frame format The basic
44、 frame structure at 139 264 kbit/s, as described in ITU-T Rec. G.832, shall be used in this case. The LAPS frames are mapped into the 2160 payload octets of the 139 264 kbit/s frame with the octet structure of the 139 264 kbit/s frame (see Figure D.6). 240 octetsOverhead octetLAPS frame header9 rows
45、Figure D.6/X.85/Y.1321 Frame structure at 139 264 kbit/s ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects Y.30
46、0Y.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 Services and applications Y.1100Y.1199 Architecture, access, network
47、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 Charging Y.1800Y.1899 NEXT GENERATION NETWORKS Frameworks and func
48、tional 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.2299 Numbering, naming and addressing Y.2300Y.2399 Network man
49、agement 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, 2004 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series B Means of expression: definitions, symbols, classification Series C General telecommunication statistics Series D General tariff principles
