1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T G.7041/Y.1303 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Corrigendum 1 (03/2018) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Data over Transport Generic aspects General SERIES Y: GLOBAL INFOR
2、MATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES Internet protocol aspects Transport Generic framing procedure Corrigendum 1 Recommendation ITU-T G.7041/Y.1303 (2016) Corrigendum 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND
3、MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERI
4、STICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC 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
5、DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE 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.7099 Transport
6、network control aspects G.7700G.7799 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.7041/Y.1303 (2016)/Cor.1 (03/2018) i Recommendation ITU-T G.7041/Y.1303 Generic framing procedure Corrigen
7、dum 1 Summary Recommendation ITU-T G.7041/Y.1303 defines a generic framing procedure (GFP) to delineate octet-aligned, variable-length payloads 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.8
8、040/Y.1340 and ITU-T G.709/Y.1331. This Recommendation defines: frame formats for protocol data units (PDUs) transferred between GFP initiation and termination points; the mapping procedure for the client signals into GFP; responses to certain defect conditions. This edition adds the information fro
9、m Amendment 1 (2012), Amendment 2 (2012) and Amendment 3 (2015) to Recommendation ITU-T G.7041 (2011), in addition to new material and text enhancements from contributions to the February 2016 meeting. Corrigendum 1 replaces a mistakenly expanded abbreviation with the correct terminology. It also pr
10、ovides some minor editorial clean-up. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.7041/Y.1303 2001-12-14 15 11.1002/1000/5644 1.1 ITU-T G.7041/Y.1303 (2001) Amd. 1 2002-06-13 15 11.1002/1000/6062 1.2 ITU-T G.7041/Y.1303 (2001) Cor. 1 2003-03-16 15 11.1002/1000/6285 1.3
11、 ITU-T G.7041/Y.1303 (2001) Amd. 2 2003-03-16 15 11.1002/1000/6284 2.0 ITU-T G.7041/Y.1303 2003-12-14 15 11.1002/1000/7082 2.1 ITU-T G.7041/Y.1303 (2003) Amd. 1 2004-10-07 15 11.1002/1000/7352 2.2 ITU-T G.7041/Y.1303 (2003) Amd. 2 2004-06-13 15 11.1002/1000/7353 2.3 ITU-T G.7041/Y.1303 (2003) Cor. 1
12、 2005-01-13 15 11.1002/1000/7476 2.4 ITU-T G.7041/Y.1303 (2003) Amd. 3 2005-01-13 15 11.1002/1000/7475 3.0 ITU-T G.7041/Y.1303 2005-08-22 15 11.1002/1000/8528 3.1 ITU-T G.7041/Y.1303 (2005) Amd. 1 2006-03-29 15 11.1002/1000/8769 3.2 ITU-T G.7041/Y.1303 (2005) Cor. 1 2006-12-14 15 11.1002/1000/8997 *
13、 To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T G.7041/Y.1303 (2016)/Cor.1 (03/2018) 3.3 ITU-T G.7041/Y.1303 (2005) Amd. 2 200
14、7-07-29 15 11.1002/1000/9170 4.0 ITU-T G.7041/Y.1303 2008-10-07 15 11.1002/1000/9399 4.1 ITU-T G.7041/Y.1303 (2008) Amd. 1 2009-01-13 15 11.1002/1000/9655 4.2 ITU-T G.7041/Y.1303 (2008) Amd. 2 2010-07-29 15 11.1002/1000/10893 5.0 ITU-T G.7041/Y.1303 2011-04-13 15 11.1002/1000/11133 5.1 ITU-T G.7041/
15、Y.1303 (2011) Amd. 1 2012-02-13 15 11.1002/1000/11506 5.2 ITU-T G.7041/Y.1303 (2011) Amd. 2 2012-10-29 15 11.1002/1000/11799 5.3 ITU-T G.7041/Y.1303 (2011) Amd. 3 2015-01-13 15 11.1002/1000/12378 6.0 ITU-T G.7041/Y.1303 2016-08-06 15 11.1002/1000/12801 6.1 ITU-T G.7041/Y.1303 (2016) Cor. 1 2018-03-1
16、6 15 11.1002/1000/13538 Keywords Generic framing procedure, optical transport network, synchronous digital hierarchy. Rec. ITU-T G.7041/Y.1303 (2016)/Cor.1 (03/2018) iii FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunicatio
17、ns, 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 standardizing telecommunications
18、 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 covered by the procedure laid
19、 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 indicate both a telecommunicat
20、ion 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 when all of these manda
21、tory 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 PROPERTY RIGHTSITU draws at
22、tention 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 asserted by ITU members or oth
23、ers outside of the Recommendation development process. As of the date of approval of this Recommendation, 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 th
24、e latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2018 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. iv Rec. ITU-T G.7041/Y.1303 (20
25、16)/Cor.1 (03/2018) Table of Contents Page 1 Scope . 1 2 References . 1 3 Terms and definitions . 3 4 Abbreviations and acronyms 4 5 Conventions 6 6 Aspects common to both frame-mapped and transparent-mapped modes of GFP 6 6.1 Basic signal structure for GFP client frames 7 6.2 GFP control frames . 1
26、8 6.3 GFP frame-level functions . 19 6.4 Management communications frame . 24 7 Payload-specific aspects for frame-mapped GFP . 24 7.1 Ethernet media access control payload . 24 7.2 HDLC/PPP payload 27 7.3 Fibre channel payload via FC-BBW_SONET . 28 7.4 Error handling in frame-mapped GFP 29 7.5 IEEE
27、 802.17 resilient packet ring payload . 29 7.6 Direct mapping of multiprotocol label switching into GFP-F frames 30 7.7 Direct mapping of IP and OSI network layer PDUs into GFP-F frames . 31 7.8 DVB ASI payload . 32 7.9 Transporting Ethernet 10GBASE-R payloads with preamble transparency and ordered
28、set information 33 7.10 Precision time protocol . 36 7.11 Synchronization status messages 37 8 Payload-specific aspects for transparent mapping of 8B/10B clients into GFP . 38 8.1 Common aspects of GFP-T 38 8.2 Running disparity in 64B/65B codes 42 8.3 Client-specific signal fail aspects . 44 8.4 Sy
29、nchronous full-rate transparent mapping of 8B/10B clients into GFP . 47 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 types . 53 Appendix III GFP frame example illustrating
30、transmission order and CRC calculation . 54 III.1 Worked example for a GFP-F frame 54 III.2 Worked example for a GFP-T superblock CRC calculation 57 III.3 Worked example for a GFP-F encapsulated MPLS frame . 57 Rec. ITU-T G.7041/Y.1303 (2016)/Cor.1 (03/2018) v Page Appendix IV Number of superblocks
31、used in transparent GFP 59 IV.1 Introduction 59 IV.2 Calculation of spare bandwidth 59 IV.3 Calculation of available bandwidth for CMFs and MCFs 60 Appendix V Bandwidth requirements for Ethernet transport . 62 Appendix VI Ethernet physical layer defect signals . 65 Appendix VII Ethernet throughput o
32、f ODUflex for GFP-F mapped client signals 67 Bibliography. 69 vi Rec. ITU-T G.7041/Y.1303 (2016)/Cor.1 (03/2018) Introduction A generic framing procedure (GFP) provides a generic mechanism to adapt traffic from higher-layer client signals over a transport network. Client signals may be protocol data
33、 unit- (PDU)-oriented such as Internet protocol/point-to-point protocol (IP/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 specification
34、 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-oriented adapt
35、ation 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 paths. G. 7041
36、-Y . 1303 (1 1) _F 01E t he rn e t IP / P P P O t he r c l i e nt s i gna l sG F P C lie nt -s pe c ifi c a s pe c ts(p a yl oa d de pe nde nt ) G F P C om m on a s pe c ts(p a yl oa d i nde pe nde nt )S D H V C - p a t hnO t he r oc t e t -s ync hr ono uspa t hs O T N O D U k pa t hFigure 1 GFP rel
37、ationship to client signals and transport paths Figure 2 illustrates the environment in which GFP operates. B r i dge or s w i t c h o r r out e r f unc t i on i n T N EP H Y - TP H Y - XG F P - T G F P - F G F P - FCB A A B C G F P - F G F P - F G F P - TP H Y - XE S C O NF I C O NF i br e c ha nne
38、 l100 0B A S ED a t a l a ye r ne t w or k B r i dge or s w i t c h o r r out e r f unc t i on i n T N ET r a ns por t l a ye r ne t w or kP H Y - T10B A S E100 B A S E100 0B A S E10G B A S EE S C O NF I C O NF i br e c ha nne l100 0B A S E10B A S E100 B A S E100 0B A S E10G B A S EFigure 2 GFP func
39、tional model (single client) 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 visibility is obtained when the client PDUs are received from either the data layer
40、network e.g., Internet protocol (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.g., an Ethernet interface (A/A in Figure 2). Rec. ITU-T G.7041/Y.
41、1303 (2016)/Cor.1 (03/2018) vii 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). Typically, inte
42、rconnections 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 with the above
43、GFP processing can be found in Appendix I.Rec. ITU-T G.7041/Y.1303 (2016)/Cor.1 (03/2018) 1 Recommendation ITU-T G.7041/Y.1303 Generic framing procedure Corrigendum 1 Editorial note: This is a complete-text publication. Modifications introduced by this corrigendum are shown in revision marks relativ
44、e to Recommendation ITU-T G.7041/Y.1303 (2016). 1 Scope This Recommendation defines a generic framing procedure (GFP) to encapsulate variable-length payload of various client signals for subsequent transport over synchronous digital hierarchy (SDH), plesiochronous digital hierarchy (PDH) and optical
45、 transport network (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 framing procedure
46、 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 mapped into ef
47、ficient 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. All Recom
48、mendations 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 regularly
49、 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 Recommendation ITU-T G.709/Y.1331 (2016), Interfaces for the optical transport network (OTN). ITU-T G.781 Recommendation ITU-T G.781 (2008), Synchronization layer functions. ITU-T G.783 Recommendatio
