Related work in other SDOs

1. Related work in other SDOs Silvana Rodrigues System Architect Phone: +1 613 2707258 silvana.rodrigues@zarlink.com http://timing.zarlink.com/

2. Standards Organizations • Multiple standards bodies are involved with Synchronisation of the Packet Network • International Telecommunication Union (ITU-T) • Defining synchronization requirements for Packet Networks • Institute of Electrical and Electronic Engineer – IEEE1588TM • Defining the Protocol to be used to carry Synchronisation over the Packet Network • IEEE802.1AS – Audio/Video Bridging Task Group • Timing and Synchronization for Time-Sensitive Applications in Bridged Local Area Networks • ATIS - Optical Transport and Synchronization Committee – OPTXS-SYNC • Defining a technical report “Synchronization of Packet Networks”

3. ITU-T – Study Group 15, Working Part 3, Question 13 – Synchronization experts group • October 2003 • Proposal for investigating precision timing synchronization requirements & characteristics over asynchronous packet Networks were presented • April 2004 – Start the work on G.pactiming • February 2006 • G.8261 (former G.pactiming) was consented • February 2006 – Question 13 decided to: • Continue to work on G.8261 • Start the work on G.paclock • Start the work on G.pacmod • Rapporteur – Jean-Loup Ferrant from Alcatel

4. ITU, Study Group 15, Question 13 cont’d • ITU-T G.8261 • Recommendation published in May 2006 available • Defines timing and synchronization elements of packet networks • Specifies the minimum equipment tolerance to jitter and wander at the boundary of the packet networks at TDM interfaces • Outlines the minimum requirements for the synchronization function of network elements • Editor: Stefano Ruffini from Ericsson • ITU-T G.pacmod • Under development • Defines various aspects related to timing distribution in packet networks and to its modeling. • Includes clock distribution (network and equipment), network equipment modeling and SSM usage • Editor: Michael Mayer from Nortel

5. ITU, Study Group 15, Question 13 cont’d • ITU-T G.paclock • Under development • Outlines minimum requirements for timing devices used in synchronizing network equipment that operates in the IWF and to other Network Elements as defined in G.8261 • Supports clock distribution based on plesiochronous and network synchronous method (e.g. Synchronous Ethernet) and packet-based methods (e.g. Adaptive and Differential Clock Recovery) • Defines clock (PLL) performance characteristics such as wander, jitter, phase transients, clock bandwidth, frequency accuracy, holdover, etc… • Synchronous Ethernet clocks will be similar to G.813 (Timing characteristics of SDH equipment slave clocks – SEC) performance characteristics • Editor: Silvana Rodrigues from Zarlink

6. IEEE-1588 • IEEE-1588 – Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems • Defines a Precision Time Protocol (PTP) designed to synchronize real-time clocks in a distributed system • Intended for Local Area Networks using multicast communications (including Ethernet) • IEEE-1588 designed to work within a building or factory • Intended typically for industrial automation and test and measurement systems (e.g. synchronized printing presses) • Targeted accuracy of microsecond to sub-microsecond • Approved in September 2002 and published November 2002 • Available from the IEEE-1588 web site • http://ieee1588.nist.gov/

7. IEEE-1588 – Version 2 • The PAR (Project Authorization Request) was approved in March 2005 • P1588 – Precise Networked Clock Synchronization Working Group was formed • Resolution of known errors • Conformance enhancements • Enhancements to address new applications (including telecom) • P1588 meets twice a week via conference calls • Chairman – John Eidson from Agilent • Secretary – Silvana Rodrigues from Zarlink • Editor – John MacKay from Progeny

8. IEEE-1588 – Version 2 cont’d • Version 2 of the standard includes key features for Telecom • Short Frame • Unicast • Fault Tolerant Clocks • Allows different methods for Master clock selection • The technical work is complete • No technical features will be introduced or deleted in the standard • Correct errors and ambiguities of technical facts • Correct editorial mistakes and English • Consider inputs from NIST for the security informative appendix • Letter ballot in April/May 2007

9. Profiles in Version 2 • Profile is a set of required options, prohibited options, and the ranges and defaults of configurable attributes • “An IEEE-1588 profile may be developed by external organizations including: a)  A recognized standards organization with jurisdiction over the industry, e.g. IEC, IEEE, IETF, ANSI, ITU, or; b)  An industry trade association or other similar organization recognized within the industry as having standards authority for the industry; c)   Other organizations as appropriate.”

10. IEEE 802.1AS • Home entertainment applications for voice, video, interactive applications and musical equipment • Trend is to use Ethernet to connect home entertainment equipment • For example, playing different audio tracks in each room, or playing same track in multiple room • Network model of 7 Switches • Synchronization accuracy • 1us maximum wander from the grand-master station • Status • PAR approved May 25, 2006 • Draft 0.6 available at http://www.ieee802.org/1/pages/802.1as.html • Editor: Geoff Garner from Samsung

11. ATIS – OPTXS • OPTXS-SYNC (formerly T1X1.3) • Working on a technical report “Synchronization of Packet Networks” • addresses synchronization issues in packet networks • The technical report is going through the letter ballot process • United States input to ITU-T • US position • Sector member contributions • Next meeting • May 2007

12. Thank you!