Precision Time Protocol aka IEEE 1588 TICTOC and

Precision Time Protocol (aka IEEE 1588) TICTOC and PWE 3 WG IETF Prague 2007 Ron Cohen Resolute Networks ronc@resolutenetworks. com

Agenda • • IEEE 1588/PTP Status Protocol overview Transparent clocks TICTOC and PWE 3 2

The Precision Time Protocol (PTP) • PTPv 1 published in 2002 • Industries involved: v 1: Industrial Automation, T&M, Military, Power Generation and Distribution § v 2 : Audio-Visio Bridges (802. 1 AS), 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: //ieee 1588. nist. gov • Version 2 PAR approved March 2005. Technical work completed 3

Protocol overview • Timing Protocol Align slaves to master time § Measure delay between master and slave § Measure per-link delay (v 2) § • Synchronization Hierarchy ‘routing’ Protocol Automatic Best Master Clock Algorithm § Determines the master-slave synchronization clock tree hierarchy § • Management Protocol § Configuration and performance monitoring 4

PTP Master-Slave Hierarchy *Clock symbols taken from ITU-T SG 15 ‘synchronization modeling components – time’ contribution #249 Geneva-2007 by Mike Gilson of BT 5

Timing Protocol Operation 6

Peer Delay Measurement (Optional) 7

End-to-End Transparent Clocks E 2 E TCs cancel queuing and processing delays 8

Peer-to-Peer Transparent Clocks P 2 P TCs cancel queuing, processing and propagation delays 9

E 2 E TC Enabled PSN Packet queuing and processing is removed 10

P 2 P TC Enabled PSN Topology change does not effect slave performance 11

An application: Use of IEEE 1588 for CES PEs use IEEE 1588 clock as common reference E 1/T 1 service clock delivered using differential timing 12

PWE 3 Architecture (single hop) Properties Emulates a native service IWF implemented at Provider Edge PSN is unaware Service and PW is bidirectional 13

PWE 3 Architecture (multi-hop) Properties PW stitching used for to provide inter-provider services PW stitching for in intra-provider network mainly in aggregation scenarios 14

TICTOC properties IEEE 1588 (and TICTOC in general) Provides frequency and time services. Can be used for emulating existing services as well as enable new services PSN can be unaware or can be enhanced by introducing boundary and transparent clocks Timing and time services are mostly unidirectional, however the timing protocol is bidirectional Timing and time services are required mostly within a single provider, from central locations to the provider edges Delivering time and timing services between providers is of no interest Boundary clock (or Transparent clocks) probably required for aggregation scenarios within a provider network 15

Summary • There are commonalities and differences between PWE 3 and TICTOC • We should figure out the relationship between TICTOC and PWE 3 in the following areas: PW architecture § PW MIB § PW signaling § TICTOC protocol mapping to MPLS/L 2 TP § 16

Thank You Ron Cohen Resolute Networks ronc@resolute. Networks. com