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.8273.2/Y.1368.2 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1 (01/2015) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Packet over Transport aspects Synchronization, quality and avail
2、ability targets SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Transport Timing characteristics of telecom boundary clocks and telecom time slave clocks Amendment 1 Recommendation ITU-T G.8273.2/Y.1368.2 (2014) Amendment
3、1 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 INTERNATIONAL CARRIER TELEPHO
4、NE 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 OPTICAL SYSTEMS CHARACTE
5、RISTICS 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 DATA OVER TRANSPORT GE
6、NERIC ASPECTS G.7000G.7999 PACKET OVER 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,
7、 please refer to the list of ITU-T Recommendations. Rec. ITU-T G.8273.2/Y.1368.2 (2014)/Amd.1 (01/2015) i Recommendation ITU-T G.8273.2/Y.1368.2 Timing characteristics of telecom boundary clocks and telecom time slave clocks Amendment 1 Summary Amendment 1 to Recommendation ITU-T G.8273.2/Y.1368.2 (
8、2014) introduces the following changes: modifies clauses 7.1, 7.1.1 and 7.1.2 adds clause 7.1.3, Dynamic time error (dTEH) high frequency noise generation adds Note 3 to Annex A modifies clause C.1.2.2 adds clause C.2.1.3, Dynamic time error (dTEH) high frequency noise generation. History Edition Re
9、commendation Approval Study Group Unique ID* 1.0 ITU-T G.8273.2/Y.1368.2 2014-05-14 15 11.1002/1000/12196 1.1 ITU-T G.8273.2/Y.1368.2 (2014) Amd. 1 2015-01-13 15 11.1002/1000/12395 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed
10、 by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T G.8273.2/Y.1368.2 (2014)/Amd.1 (01/2015) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and com
11、munication 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 on a worldwide basis.
12、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 in WTSA Resolutio
13、n 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 administration and
14、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 provisions are met
15、. 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 attention to the possibil
16、ity 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 outside of the Reco
17、mmendation development process. As of the date of approval of this Recommendation, ITU had not 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 latest informatio
18、n 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 publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.8273.2/Y.1368.2 (2014)/Amd.1 (01/2015
19、) 1 Recommendation ITU-T G.8273.2/Y.1368.2 Timing characteristics of telecom boundary clocks and telecom time slave clocks 1) Clause 7 Add the following note after the first paragraph: NOTE The 1 PPS input pertains to telecom grand master functions, and it is for further study. 2) Clause 7.1 Change
20、the following note from: NOTE The values in Table 1 are valid for 1 PPS, 1 gigabit Ethernet (GbE) and 10 GbE interfaces. Above 10 GbE is for further study. to: NOTE The values in Table 1 are valid for 1 PPS, 1 gigabit Ethernet (GbE) and 10 GbE interfaces. Values for signals above 10 GbE or below 1 G
21、bE are for further study. 3) Clause 7.1.1 Change the following note from: NOTE The values in Table 2 are valid for 1 PPS, 1 GbE and 10 GbE interfaces. Above 10 GbE is for further study. to: NOTE 1 The values in Table 2 are valid for 1 PPS, 1 GbE and 10 GbE interfaces. Values for signals above 10 GbE
22、 or below 1 GbE are for further study. 4) Clause 7.1.2 i) Change the title of clause 7.1.2 from: Dynamic time error noise generation to: Dynamic time error low-pass filtered noise generation (dTEL) ii) Add the following note after Table 7-4: NOTE Guidelines for variable temperature testing are descr
23、ibed in Appendix I of ITU-T G.8273. 5) Clause 7.1.3 Add clause 7.1.3 after clause 7.1.2 as follows: 7.1.3 Dynamic time error high-pass filtered noise generation (dTEH) For a T-BC Class A or Class B containing an EEC-Option 1 clock, and operating in a locked mode synchronized to both a noise-free tim
24、e reference at the PTP input, and a noise-free frequency reference at the SyncE/SDH input, the peak-to-peak time error at the T-BC output interfaces, measured over a 1 000 second measurement interval, with a first-order high-pass filter of 0.1 Hz must be less than 70 ns. NOTE The value of 70 ns is a
25、 conservative limit based on the SEC/EEC noise generation specification. This is based on the assumption that most of this noise is generated by the high-pass filtered noise of the SEC/EEC oscillator. It is expected that implementations based on better clocks can result in significantly lower values
26、. It is not intended and not assumed that the component of the high-pass filtered noise due to timestamp granularity is a major portion of the 70 ns. 2 Rec. ITU-T G.8273.2/Y.1368.2 (2014)/Amd.1 (01/2015) 6) Annex A Add Note 3 after Note 2 in Annex A as follows: NOTE 3 T-BC functional model is also a
27、pplicable to the T-TSC, except for the PTP master side (the T-TSC functional model includes the 1PPS and ToD interface). 7) Annex C.2.1.2 Change the title of clause C.2.1.2 from: Dynamic time error noise generation to: Dynamic time error low-pass filtered noise generation (dTEL) 8) Annex C.2.1.3 Add
28、 clause C.2.1.3 after clause C.2.1.2 as follows: C.2.1.3 Dynamic time error high-pass filtered noise generation (dTEH) For a T-TSC containing an EEC-Option 1 clock, and operating in a locked mode synchronized to both a noise-free time reference at the PTP input, and a noise-free frequency reference
29、at the SyncE/SDH input, the peak-to-peak time error at the T-TSC output interfaces, measured over a 1 000 second measurement interval, with a first-order high-pass filter of 0.1 Hz must be less than 70 ns. NOTE The value of 70 ns is a conservative limit based on the SEC/EEC noise generation specific
30、ation. This is based on the assumption that most of this noise is generated by the high-pass filtered noise of the SEC/EEC oscillator. It is expected that implementations based on better clocks can result in significantly lower values. It is not intended and not assumed that the component of the hig
31、h-pass filtered noise due to timestamp granularity is a major portion of the 70 ns. ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.20
32、0Y.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 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Arc
33、hitecture, 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.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 IPTV over NGN Y.1
34、900Y.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 architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Enh
35、ancements to NGN Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Packet-based Networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 FUTURE NETWORKS Y.3000Y.3499 CLOUD COMPUTING Y
36、.3500Y.3999 For further details, please refer to the list of ITU-T Recommendations. Printed in Switzerland Geneva, 2015 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 operati
37、on 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 services digital network Series J Cable networks and transmission of television, sound programm
38、e 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, including TMN and network maintenance Series N Maintenance: international sound programme an
39、d 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 transmission Series S Telegraph services terminal equipment Series T Terminals for telematic servi
40、ces 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
