Establishing P2MP MPLS TE LSPs draft-raggarwa-mpls-p2mp-te-02.txt Rahul Aggarwal Juniper Networks

Slide 2 Authors Rahul Aggarwal (Juniper) Liming Wei (Redback) George Apostolopous (Redback) Kireeti Kompella (Juniper) John Drake (Calient) Rahul Aggarwal (Juniper) Liming Wei (Redback) George Apostolopous (Redback) Kireeti Kompella (Juniper) John Drake (Calient)

Slide 3 Agenda Solution Recap Identifiers Secondary P2MP LSPs Non-adjacent Signaling Fast Reroute LSP Hierarchy Conclusion Solution Recap Identifiers Secondary P2MP LSPs Non-adjacent Signaling Fast Reroute LSP Hierarchy Conclusion

Slide 4 Solution Basic Requirement Rpe1 Spe1 Rpe2 Rpe3P2 P1 1.Setup a P2MP TE LSP from Spe1 to Rpe1, Rpe2, Rpe3 2.Minimize Enhancements to Current RSVP-TE

Slide 5 Solving the Practical Problem The problem is to introduce multicast functionality in the MPLS data plane –Optimize the data plane for high volume multicast –No need to optimize the control plane for multicast P2MP TE is done in the data plane Control plane uses P2P LSPs as building blocks The problem is to introduce multicast functionality in the MPLS data plane –Optimize the data plane for high volume multicast –No need to optimize the control plane for multicast P2MP TE is done in the data plane Control plane uses P2P LSPs as building blocks

Slide 6 Solution Requirements Operational simplicity –P2P RSVP-TE is deployed and understood –Leverage the existing control plane model Protocol simplicity –Minimize complex protocol changes Implementation simplicity –Minimize changes to deployed software: Less Bugs ! Operational simplicity –P2P RSVP-TE is deployed and understood –Leverage the existing control plane model Protocol simplicity –Minimize complex protocol changes Implementation simplicity –Minimize changes to deployed software: Less Bugs !

Slide 7 Solution Mechanism RSVP-TE already supports the notion of multiple P2P LSPs per session Extend this notion to build P2MP LSPs RSVP-TE already supports the notion of multiple P2P LSPs per session Extend this notion to build P2MP LSPs

Slide 8 Solution Mechanism P2MP LSP is setup by merging individual P2P TE LSPs in the network –Merge occurs in the data plane –Not in the control plane: Minimal enhancments to current RSVP-TE MPLS multicast label mappings are setup at the merge nodes P2MP LSP is setup by merging individual P2P TE LSPs in the network –Merge occurs in the data plane –Not in the control plane: Minimal enhancments to current RSVP-TE MPLS multicast label mappings are setup at the merge nodes

Slide 9 Solution Mechanism Spe initiates individual P2P LSPs to each Rpe for a given P2MP LSP –Common P2MP Session object –Distinct Sender Templates for each P2P LSP –Individual PATH messages –P2P TE ERO in each PATH message Each Rpe originates a RESV message Spe initiates individual P2P LSPs to each Rpe for a given P2MP LSP –Common P2MP Session object –Distinct Sender Templates for each P2P LSP –Individual PATH messages –P2P TE ERO in each PATH message Each Rpe originates a RESV message

Slide 10 Solution Mechanism An upstream merge node follows RSVP- TE SE style merge semantics –Allocates a merge label –Merges RESV flowspecs –Sets up a multicast label binding An upstream merge node follows RSVP- TE SE style merge semantics –Allocates a merge label –Merges RESV flowspecs –Sets up a multicast label binding

Slide 11 Solution Example Rpe1 Spe1 Rpe2 Rpe3P2 P1 L1 L2 L3 L3->{L1, L2} L4->{L5}

Slide 12 Enhancements since version 00 Identifiers Secondary P2MP LSPs Non-adjacent signaling Fast reroute Hierarchy using P2P LSPs

Slide 13 Identifiers A ‘constituent’ P2P LSP is identified by –Common session object –Unique sender template Session Object – Sender Template –

Slide 14 Secondary P2MP LSPs Multiple instances of a P2MP LSP One instance is the primary One or more secondary instances Each instance has a different LSP-ID Within an instance branch-ID of each P2P LSP is different Instances may share resources

Slide 15 Non-Adjacent Signaling Optimization to reduce PATH message processing and state on nodes that are along the common path of 2 or more branch LSPs Ingress sends the successive PATH message directly to the branch LSR where the new P2P LSP branches from the first –Path message does not contain a label request object Hence only one PATH message for a P2MP LSP instance between two nodes

Slide 16 Make Before Break Entire P2MP Tree re-optimization –A new P2MP LSP instance is signaled –The old instance is torn down after ingress moves traffic to the new instance Re-optimization of a specific branch –The re-optimized branch is signaled with a different branch ID

Slide 17 Fast Reroute Draft-ietf-mpls-rsvp-lsp-fastreroute-xx.txt mechanisms apply Facility backup –Link protection ‘just works’ –For Node protection the bypass tunnel can only backup a set of branch LSPs that pass through a common downstream MP from the PLR

Slide 18 Fast Reroute..cont One to one backup –One or more of the branch LSPs can be protected –DETOUR object inserted in the backup PATH message –Node protection possible as long as there is an alternate path to the destination

Slide 19 LSP Hierarchy A traditional P2P LSP can be used as a link of a P2MP LSP –P2P LSP is advertised as a FA by the ingress of the P2P LSP –FA is used by P2MP LSP head-end when computing the path of each branch LSP Scalability: Transit LSRs along a FA do not process P2MP control plane messages Legacy support: Transit LSRs along a FA do not have to be P2MP capable

Slide 20 Conclusion The updated revision matures the solution Mechanism re-uses RSVP-TE machinery for building P2MP LSPs and for protection Ability to signal different attributes along each constituent P2P LSP can be useful in inter-region TE Move this to a WG Doc. Comments The updated revision matures the solution Mechanism re-uses RSVP-TE machinery for building P2MP LSPs and for protection Ability to signal different attributes along each constituent P2P LSP can be useful in inter-region TE Move this to a WG Doc. Comments

Thank You! 02.txt