1. draft-chandra-mpls-rsvp-shared-labels-np-00
Node protection for RSVP-TE tunnels on a shared MPLS forwarding plane draft-chandra-mpls-rsvp-shared-labels-np-00
Chandra Ramachandran
Vishnu Pavan Beeram
Harish Sitaraman

2. draft-chandra-mpls-rsvp-shared-labels-np-00
Motivation
With the procedures specified in [draft-ietf-mpls-rsvp- shared-labels], a shared MPLS forwarding plane can be realized by allowing the TE link label to be shared by LSPs traversing the link.
Includes guidelines for providing facility backup link protection at a PLR.
This draft proposes guidelines for providing facility backup node protection at a PLR for Segment Routed RSVP-TE tunnels.

3. Node Protection B C D E At PLR B:
draft-chandra-mpls-rsvp-shared-labels-np-00
Node Protection
At PLR B:
Different node protecting bypass depending on next-next-hop LSR (MP)
Cannot use the same TE link label for B-C for LSPs unless next-next-hop LSR is also shared
Node protecting Bypass B-D
100
200 B C D
300
Node protecting Bypass B-E E

4. PLR Procedures for protecting Next-Hop Non-Delegation LSR
draft-chandra-mpls-rsvp-shared-labels-np-00
PLR Procedures for protecting Next-Hop Non-Delegation LSR
At LSR C, allocate:
321 for the TE link C-B to reach the next-next-hop LSR A
326 for the TE link C-B to reach the next-next-hop LSR F
345 for the TE link C-D to reach the next-next-hop LSR E
348 for the TE link C-D to reach the next-next-hop LSR H etc.
Forwarding actions at PLR C:
Pop the TE link label and forward the packet to the next-hop LSR
Pop the TE link label and the label beneath it and forward the packet over the node protecting bypass tunnel to the next-next-hop LSR (Merge Point).
326
321
348
345 A B C D E
376
378 F G H I

5. PLR Procedures for protecting Next-Hop Delegation LSR
draft-chandra-mpls-rsvp-shared-labels-np-00
PLR Procedures for protecting Next-Hop Delegation LSR
ETLD: 2
DHLD: 2
ETLD: 1
DHLD: 2
ETLD: 2
DHLD: 4
ETLD: 1
DHLD: 4
ETLD: 4
DHLD: 4
1300d
1500d A B C D E F
ETLD: 3
DHLD: 4
1900d L K J I H G
ETLD: 2
DHLD:4
ETLD: 3
DHLD:4
ETLD: 4
DHLD: 4
ETLD: 1
DHLD: 4
ETLD: 2
DHLD: 4
ETLD at LSR C = MIN(computed ETLD = 4, previous hop DHLD = 2).
Forwarding actions at PLR B:
Pop the TE link label and forward the packet to the next-hop LSR C
Pop the TE link label and the label beneath it and and push the label stack on behalf of the next hop delegation LSR C and forwards the packet over the node protecting bypass tunnel to the next-next-hop LSR D (Merge Point).

6. Backwards Compatibility
draft-chandra-mpls-rsvp-shared-labels-np-00
Backwards Compatibility
ETLD: 2
DHLD: 2
ETLD: 1
DHLD: 2
ETLD: 4
ETLD: 3
DHLD: 4
ETLD: 2
DHLD: 4
1300d A B C D E F
ETLD: 1
DHLD: 4
1500d L K J I H G
ETLD: 4
DHLD:4
ETLD: 1
DHLD:4
ETLD: 2
DHLD: 4
ETLD: 3
DHLD: 4
ETLD: 4
DHLD: 4
1700d
Delegation hop C does not support the DHLD extensions and hence sets ETLD normally.
B cannot push the entire label stack that C would push as a delegation hop. Instead, B can offer link protection.

7. Next Steps Request WG feedback
draft-chandra-mpls-rsvp-shared-labels-np-00
Next Steps
Request WG feedback