1. Optical Fast Reroute Adrian Farrel : Old Dog Consulting
• Protect close to the fault to minimize fault propagation times • Best-effort recovery pending end-to-end rerouting • Applicable to all MPLS traffic (RSVP-TE and LDP)
Why use Fast Reroute (FRR) in Packet Networks?
Facility Backup
MPLS FRR Features
• Protection LSPs locally computed or pre-planned • Resources guaranteed, shared, or best-effort • Protected traffic filtered by priority • FRR requires knowledge of “exit label”
Issues in Optical Networks
• LSP nesting not possible in homogeneous networks • Labels are synonymous with resources • Statistical multiplexing can’t be done • Best-effort traffic delivery doesn’t make sense
One-to-One FRR

2. LSP Stitching For Span Protection GMPLS Segment Protection (RFC 4873)
Optical FRR : Options for Deployment
Path
Resv
Switch configuration
LSP Stitching (RFC 5150)
• Looks like one-to-one FRR • Pre-planned or on-demand • 1+1 or 1:1 protection • Switchover coordination with Notify
LSP Stitching For Span Protection
• 1+1 or 1:1 protection on span • Pre-planned • End-to-end LSP stitched to protection segment • Signaling like hierarchical LSPs
GMPLS Segment Protection (RFC 4873)
• Complex, overlapping protection spans
• Source-based planning and signaling
• Association object relates all LSPs
• 1:n, m:n, and extra traffic schemes
OLD DOG CONSULTING