Last Call Review of draft-ietf-spring-problem-statement-06
review-ietf-spring-problem-statement-06-opsdir-lc-chown-2016-01-25-00
Request | Review of | draft-ietf-spring-problem-statement |
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Requested revision | No specific revision (document currently at 08) | |
Type | Last Call Review | |
Team | Ops Directorate (opsdir) | |
Deadline | 2016-02-02 | |
Requested | 2015-12-22 | |
Authors | Stefano Previdi , Clarence Filsfils , Bruno Decraene , Stephane Litkowski , Martin Horneffer , Rob Shakir | |
I-D last updated | 2016-01-25 | |
Completed reviews |
Opsdir Last Call review of -06
by Tim Chown
(diff)
Secdir Last Call review of -06 by Klaas Wierenga (diff) Genart Telechat review of -06 by Meral Shirazipour (diff) Genart Telechat review of -06 by Meral Shirazipour (diff) Genart Last Call review of -06 by Meral Shirazipour (diff) |
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Assignment | Reviewer | Tim Chown |
State | Completed | |
Request | Last Call review on draft-ietf-spring-problem-statement by Ops Directorate Assigned | |
Reviewed revision | 06 (document currently at 08) | |
Result | Has issues | |
Completed | 2016-01-25 |
review-ietf-spring-problem-statement-06-opsdir-lc-chown-2016-01-25-00
Hi, I have reviewed this document as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written with the intent of improving the operational aspects of the IETF drafts. Comments that are not addressed in last call may be included in AD reviews during the IESG review. Document editors and WG chairs should treat these comments just like any other last call comments. Overall this document is quite close to being ready, but I have a few comments below for consideration by the AD / authors. This draft is a problem statement (in the form of a number of use cases) and a set of requirements for Source Packet Routing in Networks (SPRING) or, as it is otherwise known, Segment Routing. It is one of a large number of active documents in the SPRING WG, as listed at https://tools.ietf.org/wg/spring/ . These include forays into solution space (e.g. the IPv6 SRH, tagged as a 6man draft) and the SPRING architecture, which can be found at https://tools.ietf.org/html/draft-ietf-spring-segment-routing-07 . There is clearly significant interest in the IETF in developing the SR architecture(s) and solutions. The work in SPRING is already quite advanced, and thus one might query the value of extensive effort in nailing down the problem statement and requirements. However, I feel it is proper that the WG should ensure that the basis for their published solutions has been through an appropriate consensus process, esp. should the rationale for certain requirements need to be revisited in the future. In that light, the document feels somewhat ‘note form’, in that requirements are scattered through the discussed use cases, and many are not explained in any detail (presumably as the authors assume certain level knowledge from those in the WG), e.g. what is meant by ‘shared risk constraints’? The terminology could be better explained, for a broader audience, and to reduce any potential ambiguity. The requirements take the form of (depending on how you count them) 32 SHOULDs, and there are, perhaps a little surprisingly, no MUSTs. Are the authors confident that every SHOULD is just that, and that there are no mandatory requirements? I might have queries over certain capabilities (implementations of requirements) in the document, e.g. insertion / removal of IPv6 SRHs, but I think it’s better that this document avoids drifting into discussing potential solution spaces. The Security Considerations section is quite light, though it does contain one SHOULD. I assume more detailed security discussion is to be contained in the solution documents, although I note that the Security Considerations section of the architecture document is also very brief. Tim