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(Direct) PTP over MPLS (?)

(Direct) PTP over MPLS (?). Draft-ronc-ptp-mpls-00.txt (expired). Ron Cohen IETF Maastricht 2010 ronc@ieee.org. Transports. PTP UDP IPv6. PTP UDP IPv4. PTP Ethernet. PTP Ethernet PW. PTP MPLS. PTP UDP/IP MPLS. ???. PTP Sync/Delay Message Format. Scenarios.

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(Direct) PTP over MPLS (?)

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  1. (Direct) PTP over MPLS (?) Draft-ronc-ptp-mpls-00.txt (expired) Ron Cohen IETF Maastricht 2010 ronc@ieee.org

  2. Transports PTP UDP IPv6 PTP UDP IPv4 PTP Ethernet PTP Ethernet PW PTP MPLS PTP UDP/IP MPLS ???

  3. PTP Sync/Delay Message Format

  4. Scenarios PTP Transport Service Internal Synchronization

  5. Scenarios PTP Transport Service … And Provision of Timing Services

  6. PTP Transport Service ToD/Phase Accuracy < 1us Last Hop Noise May Be Dominant

  7. PTP Transport Service As each hop adds 10us-s Noise Good QoS is required but not sufficient

  8. Desired SLA Time Error < X ns Using the Correction Fields / Timestamps Asymmetry Error < Y ns Known Asymmetry Can be Compensated At 99.999% of the time

  9. Main Requirement Must Minimize Per Flow/FEC State 1-Step TC Scalability Processing in Fast Path (Hardware) Avoid Deep Packet Inspection PTP LSPs

  10. More to handle… Avoid Legacy LSRs Selecting Co-routed LSPs

  11. Alternative: Distributed TC Approach Assuming the MPLS Edge Devices are Time Traceable Correct At Output Add TS At Input Distributed TC No special PTP awareness required by non-edge LSRs

  12. Direct PTP over MPLS Is Direct PTP over MPLS Transport Required in these ‘Tunnel’ Scenarios? No. The IP/Ethernet Layer Carries the Client addressing. In Distributed TC approach, Should Timestamps be added over MPLS Layer or in PTP? @ PTP would be applicable to other PTP Tunneling Scenarios, On the other hand @MPLS Timestamp would be applicable to NTP as well…

  13. Internal Synchronization Single Timescale Distributed Hop by Hop Solution BC or TC Implementation

  14. Why Not PTP o Layer 2 Hop by Hop - Why not use PTP directly over Layer 2? If TC support is required Forwarding is through label switching, Can not assume Layer 2 or 3 forwarding

  15. Using MPLS Protection Pre-calculate peer-to-peer delays Setup secondary and primary paths Seamless switching

  16. Using MPLS Protection With support of Fast Reroute of less < 50 ms … but FRR may not be needed for PTP LSPs

  17. And p2mp Sync Distribution

  18. Why Not IP over MPLS? Hop by Hop - Why not use PTP over IPv4/6 over MPLS ? IP Layer is Superfluous Is that all?

  19. Summary In Tunneling Scenario Direct PTP over MPLS is not needed But Extension to support Distributed TC may need to be considered In Internal Sync Scenario Direct PTP over MPLS should be considered Use of superfluous layers vs. Yet another encapsulation to Support Any other pros/cons?

  20. Thanks

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