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Precision Time Protocol (aka IEEE1588). TICTOC and PWE3 PWE3 WG IETF Prague 2007 Ron Cohen Resolute Networks ronc@resolutenetworks.com. Agenda. IEEE1588/PTP Status Protocol overview Transparent clocks TICTOC and PWE3. The Precision Time Protocol (PTP). PTPv1 published in 2002
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Precision Time Protocol (aka IEEE1588) TICTOC and PWE3 PWE3 WG IETF Prague 2007 Ron Cohen Resolute Networks ronc@resolutenetworks.com
Agenda • IEEE1588/PTP Status • Protocol overview • Transparent clocks • TICTOC and PWE3
The Precision Time Protocol (PTP) • PTPv1 published in 2002 • Industries involved: • v1: Industrial Automation, T&M, Military, Power Generation and Distribution • v2 : Audio-Visio Bridges (802.1AS), Telecom and Mobile • Symposia in 2003, 2004, 2005, and 2006. 2007 in Vienna • Products: Microprocessors, GPS Linked Clocks, Boundary Clocks, NIC Cards, Protocol Stacks, RF Instrumentation, Aircraft Flight Monitoring Instruments, etc. • Information: http://ieee1588.nist.gov • Version 2 PAR approved March 2005. Technical work completed
Protocol overview • Timing Protocol • Align slaves to master time • Measure delay between master and slave • Measure per-link delay (v2) • Synchronization Hierarchy ‘routing’ Protocol • Automatic Best Master Clock Algorithm • Determines the master-slave synchronization clock tree hierarchy • Management Protocol • Configuration and performance monitoring
PTP Master-Slave Hierarchy *Clock symbols taken from ITU-T SG15 ‘synchronization modeling components – time’ contribution #249 Geneva-2007 by Mike Gilson of BT
End-to-End Transparent Clocks E2E TCs cancel queuing and processing delays
Peer-to-Peer Transparent Clocks P2P TCs cancel queuing, processing and propagation delays
E2E TC Enabled PSN Packet queuing and processing is removed
P2P TC Enabled PSN Topology change does not effect slave performance
An application: Use of IEEE1588 for CES PEs use IEEE1588 clock as common reference E1/T1 service clock delivered using differential timing
Summary • There are commonalities and differences between PWE3 and TICTOC • We should figure out the relationship between TICTOC and PWE3 in the following areas: • PW architecture • PW MIB • PW signaling • TICTOC protocol mapping to MPLS/L2TP
Thank You Ron Cohen Resolute Networks ronc@resoluteNetworks.com