1、 International Telecommunication Union ITU-T G.7041/Y.1303TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (04/2011) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Data over Transport Generic aspects General SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECT
2、S AND NEXT-GENERATION NETWORKS Internet protocol aspects Transport Generic framing procedure Recommendation ITU-T G.7041/Y.1303 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERIST
3、ICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC
4、 LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE AND PE
5、RFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 General G.7000G.7099Transport network control aspects G.7700G.7799 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For furt
6、her details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.7041/Y.1303 (04/2011) i Recommendation ITU-T G.7041/Y.1303 Generic framing procedure Summary Recommendation ITU-T G.7041/Y.1303 defines a generic framing procedure (GFP) to delineate octet-aligned, variable-length payloads
7、from higher-level client signals for subsequent mapping into octet-synchronous paths such as those defined in Recommendations ITU-T G.707/Y.1322, ITU-T G.8040/Y.1340 and ITU-T G.709/Y.1331. This Recommendation defines: frame formats for protocol data units (PDUs) transferred between GFP initiation a
8、nd termination points; the mapping procedure for the client signals into GFP; responses to certain defect conditions. This edition adds the information from both Amendment 2 (2010) to Recommendation ITU-T G.7041 (2008) and the Implementers Guide ITU-T G.Imp7041 (2009). History Edition Recommendation
9、 Approval Study Group 1.0 ITU-T G.7041/Y.1303 2001-12-14 15 1.1 ITU-T G.7041/Y.1303 (2001) Amd. 1 2002-06-13 15 1.2 ITU-T G.7041/Y.1303 (2001) Cor. 1 2003-03-16 15 1.3 ITU-T G.7041/Y.1303 (2001) Amd. 2 2003-03-16 15 2.0 ITU-T G.7041/Y.1303 2003-12-14 15 2.1 ITU-T G.7041/Y.1303 (2003) Amd. 2 2004-06-
10、13 15 2.2 ITU-T G.7041/Y.1303 (2003) Amd. 1 2004-10-07 15 2.3 ITU-T G.7041/Y.1303 (2003) Cor. 1 2005-01-13 15 2.4 ITU-T G.7041/Y.1303 (2003) Amd. 3 2005-01-13 15 3.0 ITU-T G.7041/Y.1303 2005-08-22 15 3.1 ITU-T G.7041/Y.1303 (2005) Amd. 1 2006-03-29 15 3.2 ITU-T G.7041/Y.1303 (2005) Cor. 1 2006-12-14
11、 15 3.3 ITU-T G.7041/Y.1303 (2005) Amd. 2 2007-07-29 15 4.0 ITU-T G.7041/Y.1303 2008-10-07 15 4.1 ITU-T G.7041/Y.1303 (2008) Amd. 1 2009-01-13 15 4.2 ITU-T G.7041/Y.1303 (2008) Amd. 2 2010-07-29 15 5.0 ITU-T G.7041/Y.1303 2011-04-13 15 Keywords Generic framing procedure, optical transport network, s
12、ynchronous digital hierarchy. ii Rec. ITU-T G.7041/Y.1303 (04/2011) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Secto
13、r (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 every
14、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,
15、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 voluntary
16、. 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
17、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
18、 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
19、ion, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www
20、.itu.int/ITU-T/ipr/. ITU 2012 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.7041/Y.1303 (04/2011) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Terms and definitions . 3 4 Abbreviations
21、and acronyms 4 5 Conventions 6 6 Aspects common to both frame-mapped and transparent-mapped modes of GFP 7 6.1 Basic signal structure for GFP client frames 7 6.2 GFP control frames . 18 6.3 GFP frame-level functions . 19 6.4 Management communications frame (MCF) . 24 7 Payload-specific aspects for f
22、rame-mapped GFP . 24 7.1 Ethernet MAC payload . 24 7.2 HDLC/PPP payload 26 7.3 Fibre channel payload via FC-BBW_SONET . 28 7.4 Error handling in frame-mapped GFP 29 7.5 IEEE 802.17 RPR payload . 29 7.6 Direct mapping of MPLS into GFP-F frames 30 7.7 Direct mapping of IP and OSI network layer PDUs in
23、to GFP-F frames . 31 7.8 DVB ASI payload . 32 7.9 Transporting Ethernet 10GBASE-R payloads with preamble transparency and ordered set information 34 8 Payload-specific aspects for transparent mapping of 8B/10B clients into GFP . 37 8.1 Common aspects of GFP-T 37 8.2 Running disparity in 64B/65B code
24、s 41 8.3 Client-specific signal fail aspects . 44 8.4 Synchronous full-rate transparent mapping of 8B/10B clients into GFP . 46 8.5 Asynchronous (full- or sub-rate) mapping of 8B/10B clients into GFP 50 Appendix I Examples of functional models for GFP applications . 51 Appendix II Sample GFP payload
25、 types . 54 Appendix III GFP frame example illustrating transmission order and CRC calculation . 55 III.1 Worked example for a GFP-F frame 55 III.2 Worked example for a GFP-T superblock CRC calculation 58 III.3 Worked example for a GFP-F encapsulated MPLS frame . 58 Appendix IV Number of superblocks
26、 used in transparent GFP 60 IV.1 Introduction 60 IV.2 Calculation of “spare“ bandwidth . 60 IV.3 Calculation of available bandwidth for CMFs and MCFs 61 iv Rec. ITU-T G.7041/Y.1303 (04/2011) Page Appendix V Bandwidth requirements for Ethernet transport . 63 Appendix VI Ethernet physical layer defect
27、 signals . 67 Appendix VII Ethernet throughput of ODUflex for GFP-F mapped client signals 69 Bibliography. 71 Rec. ITU-T G.7041/Y.1303 (04/2011) v Introduction Generic framing procedure (GFP) provides a generic mechanism to adapt traffic from higher-layer client signals over a transport network. Cli
28、ent signals may be packet data unit (PDU)-oriented (such as IP/point-to-point protocol (PPP) or Ethernet media access control (MAC) or block-code oriented constant bit rate stream (such as fibre channel or enterprise systems connection/single-byte command code sets connection (ESCON/SBCON). The GFP
29、specification consists of both common and client-specific aspects. Common aspects of GFP apply to all GFP-adapted traffic and they are specified in clause 6. Client-specific aspects of GFP are specified in clauses 7 and 8. Currently, two modes of client signal adaptation are defined for GFP. A PDU-o
30、riented adaptation mode, referred to as frame-mapped GFP (GFP-F), is specified in clause 7. A block-code oriented adaptation mode, referred to as transparent GFP (GFP-T), is specified in clause 8. Figure 1 illustrates the relationship between the higher-layer client signals, GFP and GFP transport pa
31、ths. G.7041-Y.1303(11)_F01Ethernet IP/PPPOther client signalsGFP Client-specific aspects(payload dependent) GFP Common aspects(payload independent)SDH VC- pathnOther octet-synchronouspathsOTN ODUk pathFigure 1 GFP relationship to client signals and transport paths Figure 2 illustrates the environmen
32、t in which GFP operates. Bridge or switch or router function in TNEPHY-TPHY-XGFP-T GFP-F GFP-FCB AA BCGFP-F GFP-F GFP-TPHY-XESCONFICONFibre channel1000BASEData layer networkBridge or switch or router function in TNETransport layer networkPHY-T10BASE100BASE1000BASE10GBASEESCONFICONFibre channel1000BA
33、SE10BASE100BASE1000BASE10GBASEFigure 2 GFP functional model (single client) vi Rec. ITU-T G.7041/Y.1303 (04/2011) In the frame-mapped adaptation mode, the client/GFP adaptation function may operate at the data link layer (or higher layer) of the client signal. Client PDU visibility is required. This
34、 visibility is obtained when the client PDUs are received from either the data layer network (e.g., IP router fabric or Ethernet switch fabric (C/C in Figure 2) or, e.g., a bridge, switch or router function in a transport network element (TNE). In the latter case, the client PDUs are received via, e
35、.g., an Ethernet interface (A/A in Figure 2). For the transparent adaptation mode, the client/GFP adaptation function operates on the coded character stream rather than on the incoming client PDUs. Thus, processing of the incoming codeword space for the client signal is required (B/B in Figure 2). T
36、ypically, interconnections can be set up between ports A and A, B and B, C and C, A and C, and C and A. Note that the physical port type of B and B must be the same to support an interconnection, while the physical port type of A and A may be different. Some high-level functional models associated w
37、ith the above GFP processing can be found in Appendix I. Rec. ITU-T G.7041/Y.1303 (04/2011) 1 Recommendation ITU-T G.7041/Y.1303 Generic framing procedure 1 Scope This Recommendation defines a generic framing procedure (GFP) to encapsulate variable-length payload of various client signals for subseq
38、uent transport over SDH, PDH and OTN networks as defined in ITU-T G.707, ITU-T G.8040 and ITU-T G.709. This Recommendation defines the: frame formats for protocol data units (PDUs) transferred between GFP initiation and termination points; mapping procedure for the client signals into GFP. The frami
39、ng procedure described in this Recommendation can be applied to both the encapsulation of entire client frames (frame-mapped GFP) in which a single client frame is mapped into a single GFP frame, and to character-mapped transport (transparent GFP) in which a number of client data characters are mapp
40、ed into efficient block codes for transport within a GFP frame. 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.
41、 All Recommendations and other references are subject 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
42、 regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.707 Recommendation ITU-T G.707/Y.1322 (2007), Network node interface for the synchronous digital hierarchy (SDH). ITU-T G.709 Recommendati
43、on ITU-T G.709/Y.1331 (2009), Interfaces for the Optical Transport Network (OTN). ITU-T G.783 Recommendation ITU-T G.783 (2006), Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks. ITU-T G.798 Recommendation ITU-T G.798 (2006), Characteristics of optical transport net
44、work hierarchy equipment functional blocks. ITU-T G.806 Recommendation ITU-T G.806 (2006), Characteristics of transport equipment Description methodology and generic functionality. ITU-T G.8021 Recommendation ITU-T G.8021/Y.1341 (2007), Characteristics of Ethernet transport network equipment functio
45、nal blocks. ITU-T G.8040 Recommendation ITU-T G.8040/Y.1340 (2005), GFP frame mapping into Plesiochronous Digital Hierarchy (PDH). ITU-T H.222.0 Recommendation ITU-T H.222.0 (2006) | ISO/IEC 13818-1:2007, Information technology Generic coding of moving pictures and associated audio information: Syst
46、ems. ITU-T I.363.1 Recommendation ITU-T I.363.1 (1996), B-ISDN ATM Adaptation Layer specification: Type 1 AAL. ITU-T I.432.1 Recommendation ITU-T I.432.1 (1999), B-ISDN user-network interface Physical layer specification: General characteristics. 2 Rec. ITU-T G.7041/Y.1303 (04/2011) ITU-T J.131 Reco
47、mmendation ITU-T J.131 (1998), Transport of MPEG-2 signals in PDH networks. ITU-T J.132 Recommendation ITU-T J.132 (1998), Transport of MPEG-2 signals in SDH networks. ITU-T J.133 Recommendation ITU-T J.133 (2002), Measurement of MPEG-2 transport streams in networks. ITU-T X.233 Recommendation ITU-T
48、 X.233 (1997) | ISO/IEC 8473-1:1998, Information technology Protocol for providing the connectionless-mode network service: Protocol specification. ANSI INCITS 230 ANSI INCITS 230-1994, Information Technology Fibre Channel Physical and Signaling Interface (FC-PH). ANSI INCITS 296 ANSI INCITS 296-199
49、7, Information Technology Single-Byte Command Code Sets CONnection (SBCON) Architecture. BS EN 50083-9 BS EN 50083-9:2002, Cabled distribution systems for television and sound signals. Interfaces for CATV/SMATV headends and similar professional equipment for DVB/MPEG-2 transport streams. ETSI TR 101 290 ETSI TR 101 290 (2001), Digital Video Broadcasting (DVB); Measurement guidelines for DVB systems. ETSI TR 101 891 ETSI TR 101 891 (2001)
