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 Series G TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 53 (12/2014) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Guidance for Ethernet OAM performance monitoring ITU-T G-series Recomme
2、ndations Supplement 53 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION 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 INTERNAT
3、IONAL 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 LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPT
4、ICAL 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 PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 D
5、ATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. G series Supplement 53 (12/2014) i Supplement 53 to ITU-T G-series Recommendations Guidance for Ethernet OAM
6、 performance monitoring Summary Supplement 53 to ITU-T G-series Recommendations provides an overview of Ethernet operations, administration, maintenance (OAM) performance monitoring. It describes how Ethernet OAM performance measurements are processed, configured and managed as described in Recommen
7、dations ITU-T G.8013, ITU-T G.8021 and ITU-T G.8051. It also introduces the modelling for Ethernet OAM performance monitoring as described in Recommendation ITU-T G.8052. This Supplement is of an informative nature and does not imply any specific requirements. History Edition Recommendation Approval
8、 Study Group Unique ID* 1.0 ITU-T G Suppl. 53 2014-12-05 15 11.1002/1000/12361 _ * 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 G serie
9、s Supplement 53 (12/2014) 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 organ of ITU. ITU
10、-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 topics for stu
11、dy 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 prepared on a
12、collaborative basis with ISO and IEC. NOTE In this publication, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this publication is voluntary. However, the publication may contain certain m
13、andatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the publication 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 to express requirements. T
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16、d by patents, which may be required to implement this publication. 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 2015 All rights reserved. No part of this
17、 publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. G series Supplement 53 (12/2014) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Supplement 1 4 Abbreviations and acro
18、nyms 1 5 Conventions 2 6 Single-ended Ethernet loss measurement function . 2 6.1 Protocol . 2 6.2 Process 3 6.3 Management requirement . 5 6.4 Information model 5 7 Dual-ended ETH-LM 5 7.1 Protocol . 5 7.2 Process 6 7.3 Management requirement . 7 7.4 Information model 7 8 Single-ended Ethernet delay
19、 measurement function 7 8.1 Protocol . 7 8.2 Process 8 8.3 Management requirement . 8 8.4 Information model 9 9 Dual-ended ETH-DM . 9 9.1 Protocol . 9 9.2 Process 10 9.3 Management requirement . 10 9.4 Information model 11 10 Single-ended ETH-SLM . 11 10.1 Protocol . 11 10.2 Process 11 10.3 Manageme
20、nt requirement . 12 10.4 Information model 12 11 Dual-ended ETH-SLM . 12 11.1 Protocol . 12 11.2 Process 13 11.3 Management requirement . 13 11.4 Information model 13 iv G series Supplement 53 (12/2014) Page Appendix I MIs and their values for performance measurement OAM mechanisms 14 G series Suppl
21、ement 53 (12/2014) 1 Supplement 53 to ITU-T G-series Recommendations Guidance for Ethernet OAM performance monitoring 1 Scope This Supplement provides an overview of Ethernet operations, administration, maintenance (OAM) performance monitoring. It describes how Ethernet OAM performance measurements
22、are processed, configured and managed as described in ITU-T G.8013, ITU-T G.8021 and ITU-T G.8051. It also introduces the modeling for Ethernet OAM performance monitoring as described in ITU-T G.8052. This Supplement is of an informative nature and does not imply any specific requirements. 2 Referen
23、ces ITU-T G.8001 Recommendation ITU-T G.8001/Y.1354 (2013), Terms and definitions for Ethernet frames over transport. ITU-T G.8013 Recommendation ITU-T G.8013/Y.1731 (2013), OAM functions and mechanisms for Ethernet based networks. ITU-T G.8021 Recommendation ITU-T G.8021/Y.1341 (2015), Characterist
24、ics of Ethernet transport network equipment functional blocks. ITU-T G.8051 Recommendation ITU-T G.8051/Y.1345 (2013), Management aspects of the Ethernet Transport (ET) capable network element. ITU-T G.8052 Recommendation ITU-T G.8052/Y.1346 (2013), Protocol-neutral management information model for
25、the Ethernet transport capable network element. 3 Definitions 3.1 Terms defined elsewhere This Supplement uses the following terms defined elsewhere: 3.1.1 dual-ended ITU-T G.8001 3.1.2 far-end ITU-T G.8001 3.1.3 on-demand measurement ITU-T G.8001 3.1.4 one-way ITU-T G.8001 3.1.5 proactive measureme
26、nt ITU-T G.8001 3.1.6 single-ended ITU-T G.8001 3.1.7 two-way ITU-T G.8001 3.2 Terms defined in this Supplement None. 4 Abbreviations and acronyms This Supplement uses the following abbreviations and acronyms: 1DM One-way Delay Measurement 2 G series Supplement 53 (12/2014) 1SL One-way Synthetic Los
27、s Measurement CCM Continuity Check Message DA Destination MAC Address DMM Delay Measurement Message DMR Delay Measurement Reply ETH-DM Ethernet Delay Measurement function ETH-LM Ethernet Loss Measurement function ETH-SLM Ethernet Synthetic Loss Measurement function FD Frame Delay FDV Frame Delay Var
28、iation FLR Frame Loss Ratio LF Lost Frame LMM Loss Measurement Message LMR Loss Measurement Reply MEG ME Group MEP MEG End Point MI Management Information OAM Operations, Administration, Maintenance PCP Priority Code Point PDU Protocol Data Unit PM Performance Management SLM Synthetic Loss Message S
29、LR Synthetic Loss Reply TF Total Frame TLV Type, Length and Value 5 Conventions None. 6 Single-ended Ethernet loss measurement function The following clauses describe the protocol and the process used for the single-ended Ethernet loss measurement function (ETH-LM) and the corresponding management r
30、equirements and information models. 6.1 Protocol Single-ended ETH-LM is performed using loss measurement message (LMM) and loss measurement reply (LMR) protocol data units (PDUs). The measurement information carried in the PDU of the LMM/LMR protocol for both on-demand and proactive single-ended los
31、s measurement is described in clause 8.1.2 of ITU-T G.8013. The PDU format for LMM/LMR is described in clauses 9.12 and 9.13 of ITU-T G.8013. G series Supplement 53 (12/2014) 3 Loss measurements for different classes of service can be taken concurrently using single-ended ETH-LM by transmitting LMM
32、frames with different priority code point (PCP) values. Similarly, concurrent proactive and on-demand measurements are supported via use of the “Proactive“ flag in LMM and LMR PDUs. Single-ended ETH-LM is only applicable in point-to-point ME groups (MEGs) since it measures the loss of data traffic f
33、rames. Also, since it is the loss of data traffic frames that is being measured, the size of the LMM/LMR frames has no effect on the measurement. The size of the LMM/LMR frames is fixed. Measurements using single-ended ETH-LM can be inaccurate if the LMM/LMR frames traverse a link aggregation group
34、(LAG) interface. Further details can be found in Appendix VII of ITU-T G.8013. LMM frames are generated with unicast destination MAC addresses (DAs). LMM frames may be generated with a multicast Class 1 DA if multipoint measurements are desired. The detailed behaviour if more than one LMR is receive
35、d for each LMM is not defined. LMR frames are always generated with unicast DAs. 6.2 Process 6.2.1 On-demand process The overview of the process involved with on-demand single-ended ETH-LM using LMM/LMR is described in clause 8.1.9 of ITU-T G.8021. The management information (MI) signals and their v
36、alues for on-demand single-ended ETH-LM using LMM/LMR are listed in Table I.3. The results of measurement are represented via ETHDe_FT_So_MI_LM_Result (N_TF, N_LF, F_TF, F_LF) as: Near-end transmitted frames: N_TF Near-end lost frames: N_LF Far-end transmitted frames: F_TF Far-end lost frames: F_LF
37、Results are returned at the end of the test (on receipt of the ETHDe_FT_So_MI_LM_Terminate signal) or during the test (on receipt of the ETHDe_FT_So_MI_LM_Intermediate_Request signal). The counters used for single-ended ETH-LM count data traffic frames that pass through a MEG end point (MEP). They a
38、lso count certain OAM frames, as shown in Table 1. Note that different OAM frames are counted for single-ended ETH-LM and dual-ended ETH-LM. 4 G series Supplement 53 (12/2014) Table 1 Counting OAM frames for single-ended ETH-LM MEG level of the OAM frame OAM frame OpCode Counted or not counted Atomi
39、c function that receives the PDU Higher than MEP Any Counted ETHx_FT_Sk or ETHDe_FT_Sk at a higher MEG Level Equal to MEP (including frames generated by the MEP) APS, CSF Counted ETHx/ETH_A_Sk CCM Counted ETHx_FT_Sk LBM, LBR, LTM, LTR Not counted ETHDe_FT_Sk TST Not counted ETHDe_FT_Sk AIS Not speci
40、fied, only used when no data traffic is flowing ETHx/ETH_A_Sk LCK Not specified, only used when no data traffic is flowing ETHx/ETH_A_Sk DMM, DMR, 1DM Not counted ETHx_FT_Sk or ETHDe_FT_Sk LMM, LMR Not counted ETHx_FT_Sk or ETHDe_FT_Sk SLM, SLR, 1SL Not counted ETHx_FT_Sk or ETHDe_FT_Sk Lower than M
41、EP Any Not counted ETHx_FT_Sk or ETHDe_FT_Sk at a lower MEG Level It is assumed that the impact on frame loss ratio (FLR) evaluation of counting OAM frames is negligible, as long as both MEPs count the same set of OAM frames. 6.2.2 Proactive process The overview of the process involved with proactiv
42、e single-ended ETH-LM is described in clause 8.1.9 of ITU-T G.8021. The MI signals and their values for proactive single-ended ETH-LM are listed in Table I.1. The results of measurement are represented via ETH_RI_LM_Result (N_TF, N_LF, F_TF, F_LF) 1.MLM as: Near-end transmitted frames: ETHx_FT_Sk_MI
43、_pN_TF Near-end lost frames: ETHx_FT_Sk_MI_pN_LF Far-end transmitted frames: ETHx_FT_Sk_MI_pF_TF Far-end lost frames: ETHx_FT_Sk_MI_pF_LF The counters used for proactive single-ended ETH-LM are the same as those used for on-demand. See clause 6.2.1. It is assumed that the impact on FLR evaluation of
44、 counting OAM frames is negligible, as long as both MEPs count the same set of OAM frames. G series Supplement 53 (12/2014) 5 6.3 Management requirement The generic requirements of performance monitoring are described in clause 10.2 of ITU-T G.7710, including current and history, such as 15-minute a
45、nd 24-hour, data collection and thresholding. 6.3.1 Management requirement for on-demand The Ethernet-specific requirements for on-demand single-ended ETH-LM are specified in clause 10.2 of ITU-T G.8051. The relevant items for on-demand LM are 2, 5, 6, 7 and 16. In the clause, it describes four on-d
46、emand measurements: 1) Single instance; 2) Repetitive instance; 3) Single series; 4) Repetitive series. In each measurement, the mandatory parameters, such as start time, stop time, reception period, message period and measurement interval are shown in Figure 10-1 of ITU-T G.8051. The value ranges o
47、f the MI signals and the default values of the input MI signals are also specified in clause 8.6 of ITU-T G.8051. ITU-T G.8021 defines the primitives mentioned in the above list. ITU-T G.8051 defines the calculation algorithm of near-end and far-end frame loss ratio (TN_FLR and TF_FLR). 6.3.2 Manage
48、ment requirement for proactive The Ethernet-specific requirements for proactive single-ended ETH-LM are specified in clause 10.2 of ITU-T G.8051. Item 17 describes the requirement and it is in common with proactive dual-ended ETH-LM in clause 7.3. The value ranges of the MI signals and the default v
49、alues of the input MI signals for proactive single-ended ETH-LM are also specified in clause 8.5 of ITU-T G.8051. ITU-T G.8021 defines the primitives mentioned in the above list. ITU-T G.8051 defines the calculation algorithm of the temporal minimum, average and maximum statistics of near-end and far-end frame loss ratio (mN_FLR, aN_FLR, xN_FLR, mF_FLR, aF_FLR, xF_FLR). 6.4 Information model The protocol
