1. Towards PAR for Segment Protection Switching
M Vinod Kumar
Abhay Karandikar

2. Agenda Refresh Motivation Gaps in Present Standard
Terminology for Segment Protection- agreed so far
Summary of Segment Protection Requirements
Summary of Segment Protection Solutions discussed so far in the group
Pros and Cons of various solutions
Need for a PAR

3. Prior Arts
Eilat (May Interim) - Abhay presents SPS as means to solve P2MP protection
ay-Abhay-Protection-Switching-for-P2MP-0508.ppt
Denver (July Plenary) – Jointly by Abhay, Bob and John
new-sultan-fast-reroute-te-0708-v02.pdf
Seoul (Sept Interim) - Bob presents interpretations and observations, Dave presents issues to address and Vinod presents case for SPS
new-sultan-segment-protection-scaling-0908-v01.pps
new-martin-PBB-TE-segment-prot-0908-v01.pdf
new-Protection-Vinod-Case-for-Segment-Protection-0908-v1.pps
Dallas (Nov Plenary) -Vinod uploads document on case for SPS and No new work prez due to Lack of time
new-Vinod-SegmentProtectionSwitching-1108-v01.doc
new-martin-PBB-TE-segment-prot-1108-v00.pdf
new-sultan-segment-protection-requirements-1108-v02.pdf
New Orleans (Jan Interim) – Dave presents client-server method, Wei presents 3-tupple translation, Bob presents segment protection for infrastructure, and Vinod presents four distinct methods
new-martin-PBB-TE-segment-prot-0109-v00.pdf
new-weiyh-segment-protection-0109-v00.pdf
new-sultan-segment-protection-technical-proposal-0109-v01.pdf
new-vinod-SPS-modeling-0109-v1.ppt

4. Motivation Reference: Carrier Requirements:
new-Protection-Vinod-Case-for-Segment-Protection-0908-v1.pps
Carrier Requirements:
Infrastructure failure- major cause of outage
Service providers have the knowledge that certain links are more prone to failure
Upcoming areas/floods/road construction
Protection models must include N:1

5. Gaps in Present Standard
PBB-TE has addressed end-to-end protection of P2P TESI within a single domain.
Service providers need efficient mechanism to protect vulnerable links of the topology
N:1 is not addressed in PBB-TE.

6. Definitions of Segment
A Segment is a single link, or a sequence of links and bridges, providing connectivity between two bridges. The segment is bounded at each end by a Provider Network Port (PNP). A bridge lying within the segment is a BCB. A segment endpoint bridge is a BCB or an IB-BEB.
A Primary segment is a segment along whose path one or more TESIs have been coincidently provisioned
A Backup segment is a segment having the same endpoint bridges as the primary segment but whose path is otherwise disjoint from the primary segment.
An Infrastructure Segment is Sequence of links and bridges that protects atleast one TESI coincident with it
A Data Path Segment is portion of a TESI bounded by a PNP at each end
Multiple Data Path segments can be associated with an infrastructure segment
Infrastructure Protection - Preserve connectivity of all TESIs transiting an active infrastructure segment on the failure of one or more links or bridges associated with that segment.
Data Path Protection - Preserve connectivity of a TESI in the presence of a TESI data path failure occurring within the active TESI segment due to link failure, node failure, FDB corruption, etc.
M:1 Protection – Support multiple backup segments (M≥1) to which traffic can be switched in the event of the failure of the primary segment. The backup segment having the highest provisioned priority value among operational backup segments is selected to be the active segment. Should support Load Balancing. M = 3 atleast.

7. Types of Segment Protection Schemes
Infrastructure Segment Protection
Data Path Segment Protection
There is an agreement on the requirements for Infrastructure Segment Protection

8. Infrastructure Segment Protection Requirements
new-sultan-segment-protection-requirements-0109-v01.pdf
new-irene-Segment-Protection-Requirements-0309-v01.ppt
Maintain the same or better quality of transport as offered by PBB-TE
End-to-end integrity must be honored
Solution must be operationally simple and should not require large number of provisioning action
Solution shall not switch traffic when there is no fault unless required by management commands
Shall have minimal impact on bridge architecture
Shall support N:1 protection group with load sharing support
Address the relatively high failure rate of particular links or bridges within a network.
Address the likelihood of concurrent failures occurring in different segments of a network.
Allow maintenance activities to be performed independently in different segments of the network.
Provide an efficient means of protecting portions of a PtMP TESI.
Blind Switching as per Tejas are of two types:
Type 1: This arises due to not checking the switching of TESI over the backup infrastructure segment
Type 2: This concerns with the action of monitoring a segment with different identifiers, different from the actual TESI_ID, and assuming that the TESI has failed if Infrastructure segment CCM has failed.
Both type of blind switching are to be avoided in a transport network. In a data network Type 1 is enough, but in packet transport network!

9. Segment Protection Solutions
Segment Protection Solutions can be broadly classified in three types:
Hierarchical (Client server by Dave, Triple Q by Vinod Tejas)
Cascaded (Tuple switch by Wei ZTE, BB-BEB model by Vinod)
Port redirection by Bob

10. Hierarchical Segment Protection
This is also known as Client-Server model (Dave) or Triple MAC (Vinod)
Upgrade the BCBs at the edges of the segment to IB-BEBs and provide a PBB hierarchal (802.1ah ) S-tagged interface (802.1ah 25.4)􀂾
Each segment is now a new (server layer ) TESI in a regular PBB-TE 1:1 TESI PG, with the corresponding TESI CCM integrity coverage

11. Cascaded Segment Protection
Also known as 3-tupple translation (Wei Yuehua) or Enhanced BB-BEB (Vinod)

12. Overlay Segment Protection
Also known as port-redirect (Bob Sultan)
Only addresses Infrastructure Segment Protection Switching
Special logic needed at AIB and PIB to correlate the faults and port-redirect or switch the TESI without forwarding ambiguity

13. HW complexity increase Minimum HW complexity Same HW logic Yes
Features
Hierarchical PBB-TE
3-Tupple Translation
Port-redirect
Data Frame size
Increase
Same
Standards Impact
None
Minor
Hardware Logic
Same as .1ah
Same as .1ad
Placement at the BEB
HW complexity increase
Minimum HW complexity
Same HW logic
Control Plane Logic (AIB)
Yes
Retracing
Protection Scope
Group of TESIs
TESI
Group of TESI
Data Path Integrity No
Blind Switch
Scalability
CCM complexity
Per Segment
Per TESI
per AIB or PIB
Reinforcing Proposals
E-NNI v2 in MEF and IEEE
Alternate competing Standards
G.8032 v2
Support for Infrastructure
Forwarding Ambiguity

14. PAR

15. What do we get?
Protection segments are pre-provisioned to allow sub-50ms protection switching
The segments forming protection group are constantly monitored
Optimal network resource utilization
By protecting portion of e2e TESI
By supporting load sharing with N:1
By supporting minimal provisioning for protection

16. Value Proposition
Segment Protection has same economic feasibility as that of Backbone Edge Bridges
The protection mechanism is applicable to any topology
Improves network utilization by not performing e2e protection whenever possible
Reduces provisioning complexity of e2e protection mechanism by protecting portion of e2e transport
Enables protection of critical portion of a packet transport
Enables efficient protection of branches of P2MP

17. OAM requirements OAM shall reuse PBB-TE OAM components
No need to use unreliable control plane

18. What would IEEE specify
Amendment to Qay
Amend .1ag

19. Title
IEEE standard for Local and Metropolitan Area Networks --- Virtual Bridged Local Area Networks --- Amendment ?? --- Transport Segment Protection Switching

20. Scope: What project is
The scope of this project is to define feature extension of 802.1Q (2005) supporting protection of critical portion of the provisioned or traffic engineered services by offering at-least the same guarantee as offered originally by the traffic engineered services with minimal impact on existing standards

21. Scope: What Project is not
The project will only provide features necessary to support external management plane command or control plane.
The selection of protection segment and bandwidth management either through management commands or by control plane is outside the scope of this project

22. Scope: Required Features
The features specified in this project enhance, support and rely on the PBB (IEEE 802.1ah), PBB-TE (IEEE 802.1Qay), and CFM (IEEE-802.1ag) standards. In doing so, it shall:
Maintain the same or better quality of transport as offered by PBB-TE
End-to-end integrity must be honored
Solution must be operationally simple and should not require large number of provisioning action
Solution shall not switch traffic when there is no fault unless required by management commands
Shall have minimal impact on bridge architecture
Shall support N:1 protection group with load sharing support
Address the relatively high failure rate of particular links or bridges within a network.
Address the likelihood of concurrent failures occurring in different segments of a network.
Allow maintenance activities to be performed independently in different segments of the network.
Provide an efficient means of protecting portions of a PtMP TESI.

23. Purpose
An important objective of provisioned packet transport is to efficiently protection switch the traffic
Use less network resources
Sub-50 ms resiliency
Build on existing standard building blocks
Provide aggregate protection of all TESI
This project will amend the .1Q standard

24. Need for Project
Currently there is no mechanism to manage portion of a (provisioned) packet transport that is liable to fail more often than other portion of the packet transport
The project will address OAMP and protection switching of critical portion of the end-to-end packet transport and support N:1 load sharing

25. Stakeholders
Developers and users of networking for Provider network environments including networking IC developers, switch and NIC vendors, and users.

26. Thank-you