LSP Fast-Reroute Using LSP Fast-Reroute Using RSVP DetoursRSVP Detours

Ping Pan (presenter)

IETF 51, 8/6/2001

2

MotivationMotivation

• Flexible

• Protect user traffic from both link and node failure.

• Minimize user intervention and configuration.

3

OperationOperation

A B C ED

Fast-reroute Request

A B C ED

Detour Setup

A B C ED

Fast Reroute

4

Operation (detour merging)Operation (detour merging)

A E

E G

B D

F

C

Detour Merging: Merging all detour reservations that come fromdifferent ingress, but have the same egress and next-hop.

Goal: To shrink the states.

5

Protocol IssuesProtocol Issues

• Fast-Reroute RequestFast-Reroute Request– Inside Path messages– FAST-REROUTE object

• Detour path parameters (e.g. bandwidth, etc.)

• Detour Setup– Use IGP/TE to setup a new LSP– DETOUR object

• Detour destination (learnt from RRO)

• Process detour LSP’s independentlyProcess detour LSP’s independently

6

SummarySummary

• Flexible and extensibleFlexible and extensible– Guarantee CoS and b/w per LSP.

• Single solution for both node and link Single solution for both node and link protection.protection.

• Adaptive:Adaptive:– Does not require all nodes to support it.

• Minimal user intervention.Minimal user intervention.• Operational.Operational.• Require IGP/TE and RRO support.Require IGP/TE and RRO support.

7

ScalingScaling Issues Issues

• Designed to protect selective LSP’s.Designed to protect selective LSP’s.

• Support detour LSP merging to reduce Support detour LSP merging to reduce the total number of LSP’s.the total number of LSP’s.

• Refresh reduction helps!Refresh reduction helps!