Re: [spring] https://datatracker.ietf.org/doc/html/draft-filsfilscheng-spring-srv6-srh-compression-02#section-4.1.1

Gyan Mishra <hayabusagsm@gmail.com> Fri, 24 September 2021 14:54 UTC

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From: Gyan Mishra <hayabusagsm@gmail.com>
Date: Fri, 24 Sep 2021 10:53:27 -0400
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To: "Darren Dukes (ddukes)" <ddukes@cisco.com>
Cc: SPRING WG <spring@ietf.org>, "draft-filsfilscheng-spring-srv6-srh-compression@ietf.org" <draft-filsfilscheng-spring-srv6-srh-compression@ietf.org>, "spring-chairs@ietf.org" <spring-chairs@ietf.org>
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Subject: Re: [spring] https://datatracker.ietf.org/doc/html/draft-filsfilscheng-spring-srv6-srh-compression-02#section-4.1.1
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Thank you Darren!

Few comments.

I do see many early allocation for C-SID for various endpoint behaviors.

https://www.iana.org/assignments/segment-routing/segment-routing.xhtml

I was trying to find out where in the CSID draft that is stated.  Please
provide the section.

“CSID draft recommended NEXT-C-SID use for 16-bit C-SIDs, and REPLACE-C-SID
use for 32-bit C-SIDs. “

Just based on the CSID draft SRv6 forwarding plane flavors, SID formatting,
 the NEXT-C-SID used a 16-bit combined NF -Locator/Function uSID variant
where the REPLACE-C-SID uses a 32-bit combined NF-Locator/Function.

I did not see explicit verbiage as to one flavor or the other for 16 or 32
bit SID.

I believe this  information is important to be included in the analysis
draft as well.

Section 6 talks about CSID length, Block length and GIB/LIB usage but does
not specify explicitly what you are stating.

As the WG has clearly stated that they would like a single solution,
however CSID is inclusive of 2 SRv6 forwarding compression solutions not
one from the two drafts - uSID & G-SID.

So that would have to be hashed out by the WG taking into account the
 interoperability issue that is the key point of contention to having
multiple solutions from an operators perspective.

Kind Regards

Gyan



On Fri, Sep 24, 2021 at 10:10 AM Darren Dukes (ddukes) <ddukes@cisco.com>
wrote:

> Hi Gyan, as a DT member, I can answer your analysis draft question.
>
> Consistent with the requirement document, proposals were analyzed with
> 16-bit and 32-bit SID lengths, though several supported additional options.
>
> The CSID draft recommended NEXT-C-SID use for 16-bit C-SIDs, and
> REPLACE-C-SID use for 32-bit C-SIDs. The design team followed this
> recommendation in its analysis, though the CSID draft notes all flavors
> support both 16-bit and 32-bit C-SID length.
>
> Darren
>
>
>
>
>
> On 2021-09-19, 3:34 PM, "spring" <spring-bounces@ietf.org> wrote:
>
>
>
> Dear Authors
>
>
>
> After having a few discussions on threads related to the SRv6 compression
> analysis draft results, as well as WG coming to consensus on a single SRv6
> compression solution, a few critical questions have come up related to
> C-SID draft that requires clarification by the authors.
>
>
>
> The C-SID draft has 3 compression solutions below and is a combination of
> the two drafts below which introduces 2 of the 3 compression solutions with
> the  C-SID draft introduction of yet a 3rd compression solution.
>
>
>
> Which of the 3 C-SID draft compression solutions was included as part of
> the DT analysis draft results and conclusion?
>
>
>
> This is a critical question that needs to be answered for clarification on
> the C-SID draft solution.
>
>
>
> As the WG has consensus on a single solution we need to have clarification
> from the authors which of the 3 compression solutions was included in the
> analysis.
>
>
>
> The three solutions are very different and all would yield different
> analysis results.
>
>
>
> I understand the authors have called the each solution a endpoint flavor
> which I see from the IANA codepoint allocations, however each flavor is a
> different solution.
>
>
>
> https://www.iana.org/assignments/segment-routing/segment-routing.xhtml
>
>
>
> So the WG as stated would like a single solution so now we need feedback
> from the authors which of the three solutions or endpoint flavors was part
> of the DT analysis draft that the authors would like to put forward as the
> single compression solution.
>
>
>
> C-SID is a combination of the two drafts below:
>
>
>
> Combination of the two drafts below:
>
>
>
> G-SID - Generalized SID “REPLACE-C-SID”
>
>
> https://datatracker.ietf.org/doc/html/draft-cl-spring-generalized-srv6-for-cmpr-03
>
>
>
> SRv6 uSID micro-segment “ NEXT-C-SID”
>
>
> https://datatracker.ietf.org/doc/html/draft-filsfils-spring-net-pgm-extension-srv6-usid-10
>
>
>
> Kind Regards
>
>
>
> Gyan
>
> --
>
> <http://www.verizon.com/>
>
> *Gyan Mishra*
>
> *Network Solutions Architect *
>
> *Email gyan.s.mishra@verizon.com <gyan.s.mishra@verizon.com>*
>
> *M 301 502-1347*
>
>
>
-- 

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *

*Email gyan.s.mishra@verizon.com <gyan.s.mishra@verizon.com>*



*M 301 502-1347*