Re: [Idr] Éric Vyncke's No Objection on draft-ietf-idr-bgp-ls-segment-routing-msd-17: (with COMMENT)

["Eric Vyncke (evyncke)" <[e-mail]>]

Thank you Ketan, so, I now have to pay attention for “false friends” between French “impose” and English “impose” ;-)

Again, all my COMMENTS were non blocking.

Regards

-éric

From: "Ketan Talaulikar (ketant)" <[e-mail]>
Date: Thursday, 7 May 2020 at 16:57
To: Eric Vyncke <[e-mail]>, Jeff Tantsura <[e-mail]>, Alvaro Retana <[e-mail]>, Éric Vyncke via Datatracker <[e-mail]>, The IESG <[e-mail]>
Cc: Susan Hares <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>
Subject: RE: Éric Vyncke's No Objection on draft-ietf-idr-bgp-ls-segment-routing-msd-17: (with COMMENT)

Hi Eric,

I would like to clarify as a co-author on your comment related to Section 1.

The actual terminology used is “Maximum SID Depth” and “SID stack” that can be imposed and the context is at an SR Policy headend. In case of SR-MPLS it would be label stack while in case of SRv6 it would be list of segments in the SRH – both can be seen as being “imposed” (English term) by the SR Policy headend. In SR architecture RFC8402 and SR Policy architecture (draft-ietf-spring-segment-routing-policy), we have used the term SID/Segment in a data-plane neutral way for both SR-MPLS and SRv6.

The MSD types for SRv6 are documented in IGP and BGP-LS specs for SRv6 that build on the base MSD construct : e.g. https://datatracker.ietf.org/doc/html/draft-ietf-lsr-isis-srv6-extensions-08#section-4

Hope this clarifies.

Thanks,
Ketan

From: Eric Vyncke (evyncke) <[e-mail]>
Sent: 07 May 2020 19:47
To: Jeff Tantsura <[e-mail]>; Alvaro Retana <[e-mail]>; Éric Vyncke via Datatracker <[e-mail]>; The IESG <[e-mail]>
Cc: Susan Hares <[e-mail]>; [e-mail]; [e-mail]; [e-mail]
Subject: Re: Éric Vyncke's No Objection on draft-ietf-idr-bgp-ls-segment-routing-msd-17: (with COMMENT)

Jeff,

I still have some suggested changes / improvements (nothing blocking of course but in the line that this document will / should support SRv6 in the long term), updated based on Alvaro’s reply :

-- Section 1 --
In "doesn't exceed the number of SIDs the node is capable of imposing.", is it "imposing" or "processing" ? Esp. when section 1.1.1 uses the word "supported" and "label imposition" does not really fit SRv6.

If this document is only about SR-MPLS, then suggest to change title, abstract, and introduction to reflect this focus and most of my comments fall off.

-- Section 3 --
Unsure whether "MSD values may be learned via a hardware API or may be provisioned. " provides any added value.

While it is unclear to me whether this document applies only to SR-MPLS, but, if it applies also to SRv6, then is it required to be able to advertise to MSD per node ? One for SR-MPLS and one for SRv6?

Hope this helps to improve the document

-éric


From: Jeff Tantsura <[e-mail]<mailto:[e-mail]>>
Date: Thursday, 7 May 2020 at 00:00
To: Alvaro Retana <[e-mail]<mailto:[e-mail]>>, Éric Vyncke via Datatracker <[e-mail]<mailto:[e-mail]>>, The IESG <[e-mail]<mailto:[e-mail]>>, Eric Vyncke <[e-mail]<mailto:[e-mail]>>
Cc: Susan Hares <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Subject: Re: Éric Vyncke's No Objection on draft-ietf-idr-bgp-ls-segment-routing-msd-17: (with COMMENT)

Eric,

Many thanks for your review and comment.
Great to see - Alvaro has addressed all your questions!

Please let me know if there’s anything else.

Cheers,
Jeff
On May 6, 2020, 2:57 PM -0700, Eric Vyncke (evyncke) <[e-mail]<mailto:[e-mail]>>, wrote:
Alvaro

Thank you for the added piece of information. This clarifies a lot my questions/comments.

Very much appreciated,

Regards

-éric

-----Original Message-----
From: Alvaro Retana <[e-mail]<mailto:[e-mail]>>
Date: Wednesday, 6 May 2020 at 23:32
To: Éric Vyncke via Datatracker <[e-mail]<mailto:[e-mail]>>, Eric Vyncke <[e-mail]<mailto:[e-mail]>>, The IESG <[e-mail]<mailto:[e-mail]>>
Cc: Susan Hares <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Subject: Re: Éric Vyncke's No Objection on draft-ietf-idr-bgp-ls-segment-routing-msd-17: (with COMMENT)

On May 6, 2020 at 10:43:51 AM, Éric Vyncke wrote:


Eric:

Hi!

...
While it is unclear to me whether this document applies only to SR-MPLS, but,
if it applies also to SRv6...


This document is about the ability to carry the MSD in BGP-LS. The
applicability to SR-MPLS and/or SRv6 depends on the type of MSD
carried -- and with it any requirements about how to advertise, etc.

Right now there are only 2 MSD-Types defined, and both are related to
SR-MPLS [1].

If more types are defined, then those documents will have to describe
how the contents should behave and what they mean.


Thanks!

Alvaro.


[1] https://www.iana.org/assignments/igp-parameters/igp-parameters.xhtml#igp-msd-types