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Segment Protection Models

Segment Protection Models. M Vinod Kumar Dr. Abhay Karandikar. Agenda. Definitions and Abbreviations Prior art Possible models Comparison of models. Definitions and Abbreviations.

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Segment Protection Models

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  1. Segment Protection Models M Vinod Kumar Dr. Abhay Karandikar

  2. Agenda • Definitions and Abbreviations • Prior art • Possible models • Comparison of models

  3. Definitions and Abbreviations • Segment: A logical management entity defined over transitive closure of bridges and LANs or linear/open chain of connected bridges • Segment Edge Bridge (SEB): The bridge that defines end point of a segment • Infrastructure Segment (IS): • Data-path Segment (DS): • BB-BEB: 3-tupple translation bridge that translates incoming TESI to outgoing TESI. At finer granularity is may also do I-SID grooming.

  4. Prior Arts • Eilat (May Interim) • Tejas presents SPS as means to solve P2MP protection • ay-Abhay-Protection-Switching-for-P2MP-0508.ppt • Denver (July Plenary) • Jointly with Huawei and Adtran • new-sultan-fast-reroute-te-0708-v02.pdf • Seoul (Sept Interim) • Huawei presents interpretations • new-sultan-segment-protection-scaling-0908-v01.pps • Nortel presents issues to address • new-martin-PBB-TE-segment-prot-0908-v01.pdf • Tejas presents case for SPS • new-Protection-Vinod-Case-for-Segment-Protection-0908-v1.pps • Dallas (Nov Plenary) • Tejas uploads document on case for SPS • new-Vinod-SegmentProtectionSwitching-1108-v01.doc • No new work prez due to Lack of time • new-martin-PBB-TE-segment-prot-1108-v00.pdf • new-sultan-segment-protection-requirements-1108-v02.pdf • New Orleans (Jan Interim) • Tejas, Nortel, Huawei, ZTE, Adtran, …

  5. Segment Protection Models • Server Layer Model • Triple MAC or Mac-in-Mac-in-Mac • Triple Q or B-VID-in-B-VID or New VID-Ethertype • Segmented Domain Model • Segmented Q-in-Q • Segmented PBB-TE (B-B BEB)

  6. Server Layer Models Triple MAC Triple Q

  7. Triple MAC

  8. Triple MAC (SEB in middle) Work-IS 1 2 3 4 5 SEB I-tagged frame Protect-IS IB-BEB NMS trace route will be issue: inner domain is invisible to outer domain- whether it is 1-2-3-4 or 1-2-5-3-4? B-tagged frame BCB

  9. Model Components When SEB is not at the BEB S-tagged frame I-comp I-tagged MiM frame B-comp B-tagged MiM frame

  10. Triple MAC (SEB at Edge) IB-IB-BI-BI BI-IB Primary-IS 1 2 3 4 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  11. Model Component When SEB is at the BEB S-tagged frame I-comp B-comp I-comp B-comp B-tagged frame

  12. Operations and Integrity • SEB => I-comp + B-comp (Can we avoid I-comp? No) • If SEB is defined at node 4 instead of node 2 or 3 then MAC-in-MAC-in-MAC function is needed at node 4 • New and complex Chip • Integrity breaks or is not applicable as original M-i-M frame acts as client layer to the Segment Server layer • 1:1 PG integrity is not same as e2e service integrity • NMS trace route function has to maintain two valid routes 1-2-3-4 and 1-2-5-3-4 • Throughput decreases • Provisioning over segment cannot be done independently of e2e provisioning • This is contrary to Client and Server layer principle which assumes that provisioning in client and server are independent

  13. Final Model Component When SEB is not at the BEB S-tagged frame I-comp I-tagged MiM frame B-comp B-tagged MiM frame When SEB is at the BEB S-tagged frame I-comp B-comp I-comp B-comp B-tagged frame

  14. No Fault Single Fault ? ? Forwarding Ambiguity Problem • Forwarding Ambiguity arises in the two segments given below because • forwarding in Datapath segments is based on end-to-end DA+B-VID • node 5 cannot know if fault is in link 2-3 or 3-4 Primary-IS Primary-IS 1 2 3 4 Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  15. IB-IB-BI-BI BI-IB No Forwarding Ambiguity Primary-IS Primary-IS 1 2 3 4 Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB There is no forwarding ambiguity as the 3-tuple is different for every segment B-tagged frame BCB

  16. Triple Q

  17. Triple Q (SEB in Middle) Primary-IS 1 2 3 4 Additional VLAN tag for each segment 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  18. Model Component When SEB is not at the BEB B-tagged QiQ frame S-comp S-tagged QiQiQ frame New Ethertype?

  19. S-BI S-S Triple Q (SEB at Edge) Primary-IS Primary-IS 1 2 3 4 Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  20. Model Component When SEB is at the BEB S-tagged frame IB-comp S-comp S-tagged QiQiQ frame B-tagged QiQ frame New Ethertype?

  21. Operations and Integrity • SEB => S-comp + S-comp • If segment is defined at node 4 instead of node 2 or 3 then Q-in-Q-in-Q function is needed • New and complex Chip • Integrity breaks or is not applicable as original M-i-M frame acts as client layer to the Segment Server layer • 1:1 PG integrity is not same as e2e service integrity • Throughput decreases • NMS trace-route issue just as in Triple-MAC

  22. Final Model Component When SEB is not at the BEB B-tagged QiQ frame S-comp S-tagged QiQiQ frame New Ethertype? When SEB is at the BEB S-tagged frame IB-comp S-comp S-tagged QiQiQ frame B-tagged QiQ frame New Ethertype?

  23. S-S VIDs are different for every cascaded segments protecting the same service No Forwarding Ambiguity S-BI Primary-IS Primary-IS 1 2 3 4 Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  24. Segmented Domain Models Segmented Q Segmented PBB-TE or BB-BEB

  25. Segmented Q (SEB in Middle) Even though Segment is not defined between 3-4 new VLAN is needed Primary-IS 1 2 3 4 New VLAN tag for each segment 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  26. Model Component Internal point When SEB is not at the BEB B-tagged MiM frame B-comp I-tagged MiM frame B-comp B-tagged MiM frame

  27. Segmented Q (SEB at BEB) B-I B-B Primary-IS Primary-IS 1 2 3 4 New VLAN tag for each segment Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  28. Model Component When SEB is at the BEB S-tagged frame I-comp B-comp B-tagged MiM frame

  29. Operations and Integrity • Maintaining same end-to-end ESP-VID is impossible sometimes • B-VLAN translation => B-comp + B-comp • I-SID shall not be multiplexed or looked into • B-MAC remains same end-to-end; only VID changes • Blue VID terminates at 2 on to a protection group: PG(cyan, Red) • PG(cyan, Red) terminates on Brown VID (or on Blue to maintain ESP-VID requirements) • Integrity breaks or is not applicable as VID in original M-i-M frame changes within the Segment Domain • 1:1 PG integrity is not same as e2e service integrity • Throughput does not decrease as frame size is same

  30. Final Model Component Internal point When SEB is not at the BEB B-tagged MiM frame B-comp I-tagged MiM frame B-comp B-tagged MiM frame When SEB is at the BEB S-tagged frame I-comp B-comp B-tagged MiM frame

  31. No Forwarding Ambiguity B-I B-B Primary-IS Primary-IS 1 2 3 4 Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB B-MAC remains unchanged so to prevent forwarding ambiguity VID should be different B-tagged frame BCB

  32. Segmented PBB-TE or B-B BEB

  33. Segmented PBB-TE or BB-BEB (SEB in Middle) Irrespective of Segment defined between 3-4 new VLAN is needed Primary-IS 1 2 3 4 New 3-tupple for each segment 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  34. Model Component Internal point When SEB is at the BEB B-tagged MiM frame B-comp I-tagged MiM frame B-comp B-tagged MiM frame

  35. Segmented PBB-TE or BB-BEB (SEB at BEB) B-I B-B Primary-IS Primary-IS 1 2 3 4 New 3-tupple for each segment Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB B-tagged frame BCB

  36. Model Component When SEB is at the BEB S-tagged frame I-comp B-comp B-tagged MiM frame

  37. Operations and Integrity • SEB => B-comp + B-comp • TESI translation, incoming TESI is mapped to outgoing TESI • At finer granularity I-SID mux-demux can also be done • Smaller PBB-TE segments interacting as peers • Integrity is not applicable as original M-i-M frame terminates and new M-i-M frame starts • PG function is same as defined in e2e service • N:1 PG to be defined • Throughput remains same

  38. Final Model Component Internal point When SEB is not at the BEB B-tagged MiM frame B-comp I-tagged MiM frame B-comp B-tagged MiM frame When SEB is at the BEB S-tagged frame I-comp B-comp B-tagged MiM frame

  39. No Forwarding Ambiguity B-I B-B Primary-IS Primary-IS 1 2 3 4 Backup-IS 5 SEB I-tagged frame Backup-IS IB-BEB 3-tupple differs from segment to segment so there will never arise forwarding ambiguity B-tagged frame BCB

  40. Pros and Cons

  41. Questions?

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