1、 International Telecommunication Union ITU-T I.610TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 2(12/2006) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Maintenance principles B-ISDN operation and maintenance principles and functions Amendment 2: Measurement of round trip delay using loo
2、pback cell ITU-T Recommendation I.610 (1999) Amendment 2 ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL STRUCTURE Terminology I.110I.119 Description of ISDNs I.120I.129 General modelling methods I.130I.139 Telecommunication network and service attributes I.140I.149 Genera
3、l description of asynchronous transfer mode I.150I.199 SERVICE CAPABILITIES Scope I.200I.209 General aspects of services in ISDN I.210I.219 Common aspects of services in the ISDN I.220I.229 Bearer services supported by an ISDN I.230I.239 Teleservices supported by an ISDN I.240I.249 Supplementary ser
4、vices in ISDN I.250I.259 OVERALL NETWORK ASPECTS AND FUNCTIONS Network functional principles I.310I.319 Reference models I.320I.329 Numbering, addressing and routing I.330I.339 Connection types I.340I.349 Performance objectives I.350I.359 Protocol layer requirements I.360I.369 General network requir
5、ements and functions I.370I.399 ISDN USER-NETWORK INTERFACES Application of I-series Recommendations to ISDN user-network interfaces I.410I.429 Layer 1 Recommendations I.430I.439 Layer 2 Recommendations I.440I.449 Layer 3 Recommendations I.450I.459 Multiplexing, rate adaption and support of existing
6、 interfaces I.460I.469 Aspects of ISDN affecting terminal requirements I.470I.489 INTERNETWORK INTERFACES I.500I.599 MAINTENANCE PRINCIPLES I.600I.699 B-ISDN EQUIPMENT ASPECTS ATM equipment I.730I.739 Transport functions I.740I.749 Management of ATM equipment I.750I.759 Multiplexing aspects I.760I.7
7、69 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. I.610 (1999)/Amd.2 (12/2006) i ITU-T Recommendation I.610 B-ISDN operation and maintenance principles and functions Amendment 2 Measurement of round trip delay using loopback cell Summary Amendment 2 to ITU-T Recom
8、mendation I.610 (1999) defines some previously unused areas in the ATM OA&M loopback (LB) cell format to allow the cell to be used for conducting round trip delay (RTD) measurements. In particular, this amendment defines the usage of a timestamp in association with a service verification indication.
9、 Source Amendment 2 to ITU-T Recommendation I.610 (1999) was approved on 22 December 2006 by ITU-T Study Group 13 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. I.610 (1999)/Amd.2 (12/2006) FOREWORD The International Telecommunication Union (ITU) is the United Nations specia
10、lized agency in the field of telecommunications. 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 on a
11、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 down
12、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 telecommunication ad
13、ministration 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 mandatory pro
14、visions 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 RIGHTS ITU draws attention
15、 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 others out
16、side 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 the lates
17、t information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2007 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. I.610 (1999)/Amd.2 (12/2006
18、) iii CONTENTS Page 1) Clause 10.2.3 1 2) Figure 14. 1 ITU-T Rec. I.610 (1999)/Amd.2 (12/2006) 1 ITU-T Recommendation I.610 B-ISDN operation and maintenance principles and functions Amendment 2 Measurement of round trip delay using loopback cell 1) Clause 10.2.3 Add the following additional major bu
19、llets following the Source ID field bullet point: Timestamp field (4 octets): The use of this field is optional and when used contains an originating timestamp for the purpose of measuring round trip delay. This timestamp, which will be in milliseconds with a value assumed to be of local significanc
20、e only, should be present only when the service verification flag is 1 and otherwise should be set to 6AH. Flags field (1 octet): The use of this field is optional and when used contains the following two flag bits with the remaining bits always set to 110101 in transmission and ignored in reception
21、, and otherwise should be set to 6AH: Service verification indication field (1 bit): This field is set to 1 for LB cells being used to conduct round trip delay measurements, and is otherwise set to 0. Note, specific procedures for using LB cells to perform round trip delay measurements are outside o
22、f the scope of this Recommendation. Hello indication field (1 bit): This field is set to 1 for LB cells being used for CP discovery, especially in conjunction with round trip delay measurements, and is otherwise set to 0. 2) Figure 14 Replace Figure 14 with the following: Figure 14/I.610 Specific fi
23、elds for loopback cell Printed in Switzerland Geneva, 2007 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication
24、 services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against in
25、terference Series L Construction, installation and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of
26、 measuring equipment Series P Telephone transmission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission 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
