1. P. Psenak, S.Previdi, C. Filsfils – Cisco W. Henderickx – Nokia
draft-ietf-ospf-segment-routing-extensions-10 draft-ietf-ospf-ospfv3-segment-routing-extensions-07
P. Psenak, S.Previdi, C. Filsfils – Cisco
W. Henderickx – Nokia
Jeff Tantsura
H. Gredler, RtBrick
R. Shakir, Jive Communications

2. OSPF SR Drafts Evolution
Originally posted in June 2013 – IETF 87
Drafts went through several rounds of updates
Presented in IETF 88, IETF 90, IETF91, IETF93, IETF94, IETF95, IETF96, IETF97.
OSPFv2/v3 SR drafts are kept in sync

3. Changes since last IETF
Handling of multiple SR-Algorithm sub-TLVs on receiver side has been clarified in section 3.1
Similar rules are used for other SR capability sub-TLVs
SR Local Block Sub-TLV
SRMS Preference Sub-TLV

4. Changes since last IETF (cont.)
SR Local Block Sub-TLV was introduced in section 3.3.
Contains the range of labels the node has reserved for local SIDs.
Adjacency-SIDs, Binding-SIDs, etc.

5. Changes since last IETF (cont.)
SRMS Preference Sub-TLV was introduced in section 3.4.
Used to advertise a preference associated with the node that acts as a SR Mapping Server
Usage described in draft-ietf-spring-conflict-resolution

6. Changes since last IETF (cont.)
Text has been added to clarify the handling of the Algorithm in the Prefix-SID:
“A router receiving a Prefix-SID from a remote node and with an algorithm value that such remote node has not advertised in the SR-Algorithm sub-TLV (Section 3.1) MUST ignore the Prefix-SID sub- TLV.”

7. Changes since last IETF (cont.)
Below text has been removed from the draft.
SID preference rules are now described in draft-ietf-spring-conflict-resolution
“If the Prefix-SID that is advertised in a Prefix SID Sub-TLV is also covered by the OSPF Extended Prefix Range TLV, the Prefix-SID advertised in Prefix SID Sub-TLV MUST be preferred.”

8. Next Steps Socialize draft changes at IETF 97
Discuss changes on mailing list
Gauge readiness for WGLC