[mpls] Re: Rtgdir last call review of draft-ietf-mpls-sr-epe-oam-15

[Joel Halpern <[e-mail]>]

Thank you Shraddha.  In line, marked <jmh></jmh>

Yours,

Joel

On 5/8/2024 4:54 AM, Shraddha Hegde wrote:
> Hi Joel,
>
> Thank you for the careful review and comments.
> Pls see inline <SH> for responses.
>
>
> Rgds
> Shraddha
>
>
> Juniper Business Use Only
> -----Original Message-----
> From: Joel Halpern via Datatracker <[e-mail]>
> Sent: Tuesday, May 7, 2024 10:37 PM
> To: [e-mail]
> Cc: [e-mail]; [e-mail]; [e-mail]
> Subject: Rtgdir last call review of draft-ietf-mpls-sr-epe-oam-15
>
> [External Email. Be cautious of content]
>
>
> Reviewer: Joel Halpern
> Review result: Not Ready
>
> 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 https://urldefense.com/v3/__https://wiki.ietf.org/en/group/rtg/RtgDir__;!!NEt6yMaO-gk!AhctNGPPaKLQ_H79A9RESTF3a29btJzh4iO8NHGpWZzqq9EuPQTv9jm2O_41fO-qR1mCgCzII3RUBXYp$
>
> 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-name-version
> Reviewer: your-name
> Review Date: date
> IETF LC End Date: date-if-known
> Intended Status: copy-from-I-D
>
> Summary:
> I have significant concerns about this document and recommend that the Routing ADs discuss these issues further with the authors.
>
> Comments:
>
> I was very pleased with the clarity and readability of the document.  It lays out the space it is working in, and explains what it does and how very well.
>
> Major Issues:
>      I have significant concern with the structure of the TLVs in two regards.
>      First, the PeerAdj SID Sub-TLV (assigned tbd1 in section 4, defined in
>      section 4.1) uses a single code point for IPv4 and IPv6 and differentiates
>      by length.  Other sub-TLVs for MPLS ping and traceroute use different code
>      points for IPv4 and IPv6. Second, all of the sub-TLVs defined in section 4
>      have length codes.  Looking at RFC 8029, sub-TLVs are defined with fixed
>      lengths and do not have length codes embedded in them.  While one can argue
>      that this is a bad practice, it is the practice, and RFC 8287 follows that
>      practice.  It would seem this document should do so as well.
> <SH> The definition of PeerAdjSID was referenced from IGP Adj SID FEC definition from
> Sec 5.3 of RFC 8287. This uses sigle code point for IPv4/IPv6 addresses. Similar approach is
> Used in PeerAdjSID definition to keep it consistent. Let me know what you think.

<jmh>From where I sit, given that these sub-TLVs are part of the MPLS 
PING and Traceroute protocol, alignment with that protocol is more 
important than aligning with the wire encoding BGP uses.  After all, the 
comparison process inside the router can easily convert between the two 
representations.  In the end whether to leave this as is or align with 
the rest of the MPLS traceroute and ping protocol is up to the MPLS WG 
chairs and the responsible AD.

If the WG already discussed this, pointers to that discussion would seem 
helpful to those responsible for deciding.

</jmh>

>
> Minor Issues:
>      It would be helpful if the document directly referenced RFC 8029 and said
>      that 8029 is where the TLVs that can carry these sub-TLVs is defined.  That
>      should be a normative reference.
> <SH> RFC 8029 is already under normative reference. I'll add text explaining
> RFC 8029 defines main TLVs where these sub-TLVs are carried. Thanks for pointing out.
<jmh>Thank you.</jmh>
>
>
>