establishing p2mp mpls te lsps draft-raggarwa-mpls-p2mp-te-02.txt
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Establishing P2MP MPLS TE LSPs draft-raggarwa-mpls-p2mp-te-02.txt. Rahul Aggarwal Juniper Networks. Authors. Rahul Aggarwal (Juniper) Liming Wei (Redback) George Apostolopous (Redback) Kireeti Kompella (Juniper) John Drake (Calient). Agenda. Solution Recap Identifiers - PowerPoint PPT PresentationTRANSCRIPT
Establishing P2MP MPLS TE LSPsdraft-raggarwa-mpls-p2mp-te-02.txt
Rahul AggarwalJuniper 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
Rpe3P2P1
1. Setup a P2MP TE LSP from Spe1 to Rpe1, Rpe2, Rpe32. 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
SolutionRequirements
• 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
SolutionMechanism
• 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
SolutionMechanism
• 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
SolutionMechanism
• 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
SolutionMechanism
• 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
Rpe3P2P1
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– <Source Address, Tunnel ID, Application
ID>
• Sender Template– <Destination Address, LSP-ID, Branch ID>
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!
http://www.ietf.org/internet-drafts/draft-raggarwa-mpls-p2mp-te-02.txt
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