1、 International Telecommunication Union ITU-T Y.1563TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(12/2009) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Quality of service and network performance Ethernet fr
2、ame transfer and availability performanceAmendment 1: New Annex B Terminology for consecutive severely errored seconds in Ethernet services Recommendation ITU-T Y.1563 (2009) Amendment 1 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION N
3、ETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects Y.300Y.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 Performanc
4、es Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Architecture, access, network capabilities and resource management Y.1200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599Signalling Y.160
5、0Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 IPTV over NGN Y.1900Y.1999 NEXT GENERATION NETWORKS Frameworks and functional architecture models Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service archit
6、ecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Numbering, naming and addressing Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Future networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mob
7、ility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.1563 (2009)/Amd.1 (12/2009) i Recommendation ITU-T Y.1563 Ethernet frame transfer and availability performance Amendment 1 New Annex B Terminology for c
8、onsecutive severely errored seconds in Ethernet services Summary Recommendation ITU-T Y.1563 for Ethernet performance and availability parameters includes a definition for severely errored seconds (SESs). As the quantification of consecutive SESs has been useful in the past, and the definition is wi
9、dely implemented in other ITU-T Recommendations, Annex B to Recommendation ITU-T Y.1563 gives a definition of consecutive SESs. Source Amendment 1 to Recommendation ITU-T Y.1563 (2009) was approved on 14 December 2009 by ITU-T Study Group 12 (2009-2012) under Recommendation ITU-T A.8 procedures. ii
10、Rec. ITU-T Y.1563 (2009)/Amd.1 (12/2009) 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 or
11、gan 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
12、 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
13、 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 Recommendati
14、on 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 t
15、o 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 use of a claimed Intellectua
16、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 not received not
17、ice 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
18、2010 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 Y.1563 (2009)/Amd.1 (12/2009) 1 Recommendation ITU-T Y.1563 Ethernet frame transfer and availability performance Amendment 1 New Annex B Terminolo
19、gy for consecutive severely errored seconds in Ethernet services (This annex forms an integral part of this Recommendation) B.1 Introduction The body of this Recommendation specifies a normative definition for severely errored second performance of Ethernet services (SESETH) in clause 9.1. This anne
20、x defines a related parameter which can be used to quantify short-time outages of more than one-second duration, consecutive severely errored seconds for Ethernet services (CSESETH). B.2 Definition of consecutive severely errored seconds for Ethernet services (CSESETH) A CSESETHoutcome is detected a
21、t an egress MPiwhen two or more SESETHoutcomes occur for blocks of frames observed during consecutive one-second intervals at ingress MP0. The consecutive sequence terminates when a second occurs with insufficient frame loss to qualify as an SESETHoutcome. CSESETHoutcomes are not detected during una
22、vailable time. Since the SESETHoutcome is dependent on frame loss ratio (FLR) (i.e., an SESETHoccurs when the ratio of lost frames to total frames in the block at egress MPiexceeds s1), CSESETHis also dependent on the loss threshold, s1, and the provisional value of s1= 0.5 is used. B.3 Definition o
23、f n-CSESETHfor Ethernet services An n-CSESETHoutcome is detected at an egress MPiwhen n or more SESETHoutcomes occur for blocks of frames observed during consecutive one-second intervals at ingress MP0. The permissible values for n range from 2 to 9, inclusive. n-CSESETHoutcomes are not detected dur
24、ing unavailable time. The variable n permits the user to focus on a particular CSESETHduration of interest. B.4 Form of n-CSESETHobjectives for Ethernet services Numerical objectives for n-CSESETHwill usually be expressed as a limit on the frequency of the outcomes (for a pair of ingress and egress
25、MP) per unit time. Usually one value of n will be chosen as a basis for the objectives. For example, the objective could be specified as less than X n-CSESETHoutcomes per month. Printed in Switzerland Geneva, 2010 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D Ge
26、neral tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated s
27、ervices digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant Series M Telecommunication management
28、, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Terminals and subjective and objective assessment methods Series Q Switching and signalling Series R Telegraph tran
29、smission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
