Last Call Review of draft-ietf-isis-sr-yang-17
review-ietf-isis-sr-yang-17-rtgdir-lc-peng-2023-11-24-00

Hello,

I have been selected as the Routing Directorate reviewer for this draft. The
Routing Directorate seeks to review all routing or routing-related drafts as
they pass through IETF last call and IESG review, and sometimes on special
request. The purpose of the review is to provide assistance to the Routing ADs.
For more information about the Routing Directorate, please see
​http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir

Although these comments are primarily for the use of the Routing ADs, it would
be helpful if you could consider them along with any other IETF Last Call
comments that you receive, and strive to resolve them through discussion or by
updating the draft.

Document: draft-ietf-isis-sr-yang
Reviewer: Shuping Peng
Review Date: 2023-11-24
IETF LC End Date: 2023-11-30
Intended Status: Standards

Summary:
I have some minor concerns about this document that I think should be resolved
before publication.

Major Issues:
 "No major issues found."

Minor Issues:
1. Page 3, when configure adjacency-sid, do we need to indicate the neighbor's
systemid or IP in order to differentiate the different neighbors in the case of
having multiple neighbors?

augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:interfaces
          /isis:interface:
    +--rw segment-routing
       +--rw adjacency-sid
          +--rw adj-sids* [value]
          |  +--rw value-type?   enumeration
          |  +--rw value         uint32
          |  +--rw protected?    boolean

2. Page 4, since LFA, RLFA and TI-LFA are the three algorithm for computing
backup paths, why they are not in sibling relationship?

  augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:interfaces
          /isis:interface/isis:fast-reroute:
    +--rw ti-lfa {ti-lfa}?
       +--rw enable?   boolean
  augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:interfaces
          /isis:interface/isis:fast-reroute/isis:lfa/isis:remote-lfa:
    +--rw use-segment-routing-path?   boolean {remote-lfa-sr}?

3. Page 4, the keys of the global-block and local-block are not clear.

  augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:router-capabilities:
    +--ro sr-capability
    |  +--ro sr-capability
    |  |  +--ro sr-capability-bits*   identityref
    |  +--ro global-blocks
    |     +--ro global-block* []
    |        +--ro range-size?    uint32
    |        +--ro sid-sub-tlv
    |           +--ro sid?   uint32
    +--ro sr-algorithms
    |  +--ro sr-algorithm*   uint8
    +--ro local-blocks
    |  +--ro local-block* []
    |     +--ro range-size?    uint32
    |     +--ro sid-sub-tlv
    |        +--ro sid?   uint32
    +--ro srms-preference
       +--ro preference?   uint8

4. Currently there is no configuration node for the micro loop avoidance
(https://datatracker.ietf.org/doc/draft-bashandy-rtgwg-segment-routing-uloop/),
any thoughts or plan on it?