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.8031/Y.1342 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1 (03/2018) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Packet over Transport aspects Ethernet over Transport aspects SERIES
2、 Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES Internet protocol aspects Transport Ethernet linear protection switching Amendment 1 Recommendation ITU-T G.8031/Y.1342 (2015) Amendment 1 ITU-T G-SERIES RECOMMENDATIONS TR
3、ANSMISSION SYSTEMS AND 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
4、.399 GENERAL CHARACTERISTICS 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
5、 EQUIPMENTS G.700G.799 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 PACKET O
6、VER TRANSPORT ASPECTS G.8000G.8999 Ethernet over Transport aspects G.8000G.8099 MPLS over Transport aspects G.8100G.8199 Synchronization, quality and availability targets G.8200G.8299 Service Management G.8600G.8699 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T
7、Recommendations. Rec. ITU-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) i Recommendation ITU-T G.8031/Y.1342 Ethernet linear protection switching Amendment 1 Summary Recommendation ITU-T G.8031/Y.1342 describes the specifics of linear protection switching for Ethernet VLAN signals. Included are details per
8、taining to ETH linear protection characteristics, architectures and the automatic protection switching (APS) protocol. The protection scheme considered in this Recommendation is: VLAN-based Ethernet subnetwork connection linear protection with sublayer monitoring. History Edition Recommendation Appr
9、oval Study Group Unique ID* 1.0 ITU-T G.8031/Y.1342 2006-06-06 15 11.1002/1000/8779 1.1 ITU-T G.8031/Y.1342 (2006) Amd. 1 2007-10-07 15 11.1002/1000/9174 1.2 ITU-T G.8031/Y.1342 (2006) Cor. 1 2008-06-06 15 11.1002/1000/9392 2.0 ITU-T G.8031/Y.1342 2009-11-13 15 11.1002/1000/10429 2.1 ITU-T G.8031/Y.
10、1342 (2009) Cor. 1 2010-09-06 15 11.1002/1000/10901 3.0 ITU-T G.8031/Y.1342 2011-06-22 15 11.1002/1000/11138 3.1 ITU-T G.8031/Y.1342 (2011) Cor. 1 2012-02-13 15 11.1002/1000/11513 3.2 ITU-T G.8031/Y.1342 (2011) Amd.1 2013-08-29 15 11.1002/1000/12031 4.0 ITU-T G.8031/Y.1342 2015-01-13 15 11.1002/1000
11、/12383 4.1 ITU-T G.8031/Y.1342 (2015) Amd. 1 2018-03-16 15 11.1002/1000/13545 _ * 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
12、-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) 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 Sector (ITU-T) is a permanent org
13、an 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 four years, establishes the
14、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, the necessary standards are
15、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. However, the Recommendatio
16、n 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 negative equivalents are used
17、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 attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectua
18、l 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 Recommendation, ITU had received notice
19、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.itu.int/ITU-T/ipr/. ITU 2018
20、 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.8031/Y.1342 (2015)/Amd.1 (03/2018) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms d
21、efined in this Recommendation . 5 4 Abbreviations and acronyms 5 5 Conventions 6 5.1 Representation of octets . 6 6 Introduction . 6 7 Network objectives . 7 8 Protection characteristics 8 8.1 Monitoring methods and conditions . 8 9 Protection group commands . 9 9.1 End-to-end commands and states .
22、9 9.2 Local commands . 9 10 Protection architectures 9 10.1 Unidirectional and bidirectional switching 10 10.2 Need for APS communication 10 10.3 Revertive and non-revertive switching . 10 10.4 Provisioning mismatches 11 10.5 Protection switching trigger . 11 10.6 Protection switching models . 11 11
23、 APS Protocol 18 11.1 APS format . 18 11.2 1-phase APS protocol . 20 11.3 Request type . 23 11.4 Protection types and bridge type 23 11.5 Requested signal . 24 11.6 Bridged signal . 24 11.7 Control of bridge 24 11.8 Control of selector 24 11.9 Signal fail of the protection transport entity . 25 11.1
24、0 Equal priority requests 25 11.11 Command acceptance and retention . 25 11.12 Hold-off timer . 26 11.13 Wait-to-restore timer 26 11.14 Exercise operation 26 iv Rec. ITU-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) Page 11.15 Failure of protocol defects 27 11.16 Signal degrade of the protection transport
25、entity . 27 Annex A State transition tables of protection switching. 28 A.1 State transition for 1:1 bidirectional switching with revertive mode . 28 A.2 State transition for 1:1 bidirectional switching with non-revertive mode 32 A.3 State transition for 1+1 bidirectional switching with revertive mo
26、de 37 A.4 State transition for 1+1 bidirectional switching with non-revertive mode . 42 A.5 State transition for 1+1 unidirectional switching with revertive mode 48 A.6 State transition for 1+1 unidirectional switching with non-revertive mode . 49 Appendix I Operation example of 1-phase APS protocol
27、 . 52 I.1 Introduction 52 I.2 Example scenario 52 I.3 APS protocol examples 52 Appendix II Interaction between Ethernet protection switching and STP 55 Appendix III MIPs for protection switching environment 57 III.1 Introduction 57 III.2 Considerations 57 III.3 Configuration examples 58 Appendix IV
28、State transition diagrams using SDL . 60 IV.1 Introduction 60 IV.2 SDL diagrams . 60 Rec. ITU-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) 1 Recommendation ITU-T G.8031/Y.1342 Ethernet linear protection switching Amendment 1 Editorial note: This is a complete-text publication. Modifications introduced by
29、this amendment are shown in revision marks relative to Recommendation ITU-T G.8031/Y.1342 (2015). 1 Scope This Recommendation defines the automatic protection switching (APS) protocol and linear protection switching mechanisms for point-to-point VLAN-based ETH subnetwork connection (SNC) in Ethernet
30、 transport networks. All other protection schemes including point-to-multipoint and multipoint-to-multipoint are for further study. Linear 1+1 and 1:1 protection switching architectures with unidirectional and bidirectional switching are defined in this version of the Recommendation. The APS protoco
31、l and protection switching operation for all other Ethernet network architectures (e.g., ring, mesh) are for further study. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At
32、 the time of publication, the editions indicated were valid. 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 b
33、elow. A list of the currently valid ITU-T Recommendations is 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.780 Recommendation ITU-T G.780/Y.1351 (2010), Terms and definitions for synchr
34、onous digital hierarchy (SDH) networks. ITU-T G.805 Recommendation ITU-T G.805 (2000), Generic functional architecture of transport networks. ITU-T G.806 Recommendation ITU-T G.806 (2012), Characteristics of transport equipment Description methodology and generic functionality, plus Corrigendum 1 (2
35、012), Corrigendum 2 (2016), Corrigendum 3 (2017). ITU-T G.808.1 Recommendation ITU-T G.808.1 (20142016), Generic protection switching Linear trail and subnetwork protectionTerms and definitions for network protection and restoration. ITU-T G.870 Recommendation ITU-T G.870/Y.1352 (20122016), Terms an
36、d definitions for Optical Transport Networks, plus Corrigendum 1 (2013). ITU-T G.8010 ITU-T Recommendation G.8010/Y.1306 (2004), Architecture of Ethernet layer networks, plus Erratum 1 (2007), Erratum 2 (2007), Amendment 1 (2006), Amendment 2 (2010). ITU-T G.8013 Recommendation ITU-T G.8013/Y.1731 (
37、20132015), Operation, administration and maintenance (OAM) functions and mechanisms for Ethernet- based networks, plus Amendment Corrigendum 1 (20152018). 2 Rec. ITU-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) ITU-T G.8021 Recommendation ITU-T G.8021/Y.1341 (20152018), Characteristics of Ethernet transpo
38、rt network equipment functional blocks. IEEE 802.1Q IEEE Std 802.1Q-2014, IEEE Standard for Local and Metropolitan Area networksBridges and Bridged Networks. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: Terms defined in ITU-T G.780: 3.1.1
39、bidirectional protection switching 3.1.2 unidirectional protection switching Terms defined in ITU-T G.805: 3.1.3 adapted information 3.1.4 characteristic information 3.1.5 link 3.1.6 link connection 3.1.7 tandem connection 3.1.8 trail 3.1.9 trail termination 3.1.10 transport entity Terms defined in
40、ITU-T G.808: 3.1.11 (1:1)n protection architecture 3.1.12 1:n (protection) architecture (n 1) 3.1.13 1+1 (protection) architecture 3.1.14 active transport entity 3.1.15 APS protocol 3.1.16 APS protocol: 1-phase 3.1.17 bridge 3.1.18 broadcast bridge 3.1.19 detection time 3.1.20 head-end 3.1.21 hold-o
41、ff time 3.1.22 inherent monitored (/I) 3.1.23 network connection protection 3.1.24 non-intrusive monitored (/N) 3.1.25 non-revertive (protection) operation 3.1.26 normal traffic signal 3.1.27 null signal Rec. ITU-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) 3 3.1.28 permanent bridge 3.1.29 protected domai
42、n 3.1.30 protection 3.1.31 protection class: group 3.1.32 protection class: individual 3.1.33 protection class: trail protection 3.1.34 protection transport entity 3.1.35 revertive (protection) operation 3.1.36 selector 3.1.37 selector bridge 3.1.38 sink node 3.1.39 source node 3.1.40 standby transp
43、ort entity 3.1.41 sublayer monitored (/S) 3.1.42 subnetwork connection protection 3.1.43 switch 3.1.44 tail-end 3.1.45 test monitored (/T) 3.1.46 transfer time (Tt) 3.1.47 wait-to-restore time 3.1.48 working transport entity Terms defined in ITU-T G.806: 3.1.49 atomic function 3.1.50 defect 3.1.51 f
44、ailure 3.1.52 server signal degrade (SSD) 3.1.53 server signal fail (SSF) 3.1.54 signal degrade (SD) 3.1.55 signal fail (SF) 3.1.56 trail signal degrade (TSD) 3.1.57 trail signal fail (TSF) Terms defined in ITU-T G.808.1: 3.1.19 transfer time (Tt) Terms defined in ITU-T G.870: 3.1.20 APS protocol 3.
45、1.20.1 1-phase 3.1.21 protection class 4 Rec. ITU-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) 3.1.21.1 individual 3.1.21.2 group 3.1.21.3 network connection protection 3.1.21.4 subnetwork connection protection 3.1.21.4.1 sublayer monitored (/S) 3.1.21.4.2 non-intrusive monitored 3.1.21.4.3 inherent monit
46、ored 3.1.21.4.4 test monitored (/T) 3.1.21.5 trail protection 3.1.22 switch 3.1.23 component 3.1.23.1 protected domain 3.1.23.2 bridge 3.1.23.2.1 permanent bridge 3.1.23.2.2 broadcast bridge 3.1.23.2.3 selector bridge 3.1.23.3 selector 3.1.23.3.1 selective selector 3.1.23.4 head end 3.1.23.5 tail en
47、d 3.1.23.6 sink node 3.1.23.7 source node 3.1.23.8 intermediate node 3.1.24 architecture 3.1.24.1 1+1 protection architecture 3.1.24.2 1:n protection architecture 3.1.24.3 (1:1)n protection architecture 3.1.25 signal 3.1.25.1 traffic signal 3.1.25.2 normal traffic signal 3.1.25.3 extra traffic signa
48、l 3.1.25.4 null signal 3.1.26 time 3.1.26.1 detection time 3.1.26.2 hold-off time 3.1.26.3 wait-to-restore time 3.1.26.4 switching time Rec. ITU-T G.8031/Y.1342 (2015)/Amd.1 (03/2018) 5 3.1.27 transport entity 3.1.27.1 protection transport entity 3.1.27.2 working transport entity 3.1.27.3 active tra
49、nsport entity 3.1.27.4 standby transport entity 3.1.28 protection 3.1.29 impairment 3.1.30 protection ratio 3.1.31 revertive (protection) operation 3.1.32 non-revertive (protection) operation Terms defined in ITU-T G.8010: 3.1.58 Ethernet characteristic information (ETH_CI) 3.1.59 Ethernet flow point (ETH_FP) 3.1.60 maintenance entity 3.1.61 maintenance entity group 3.1.62 maintenance entity group end point (MEP) 3.1.63 maintenance entity group l
