Re: [Bier] Last Call: <draft-ietf-bier-tether-04.txt> (Tethering A BIER Router To A BIER incapable Router) to Proposed Standard

["Les Ginsberg (ginsberg)" <[e-mail]>]

This draft is at a minimum underspecified and has some technical errors in the encoding which should be addressed prior to publication.

There is no discussion as to what the "address" should be in the proposed "BIER Helped node" sub-sub-TLVs.
I would presume that what should be used is the "Router-ID" as specified in the various protocols - but there is no mention of this and I think there should be.

As there is provision for IPv4 and/or IPv6, this suggests that a given router could send two such sub-sub-TLVs - one for each address-family. But there is no discussion as to whether this is allowed nor is it discussed what would happen if a given node advertised multiple such sub-sub-TLVs for the same address family.

The name as defined in the IANA section is "BIER Helped Node" - but I would think this was meant to be "BIER Helper Node". (I could argue that a more apt name would be "BIER Tether Node".)

The encoding defined in Section 3.1 needs to be made protocol specific. OSPF typically pads things to a four byte boundary, but IS-IS does not - which means the "Reserved" field should not be present for IS-IS.

I am not enamored of this technology - but at this time I will refrain from commenting further as the WG seems to have decided to go forward.
But please address the comments above.

Apologies for the lateness of these comments.

   Les


> -----Original Message-----
> From: BIER <[e-mail]> On Behalf Of The IESG
> Sent: Thursday, February 15, 2024 6:22 AM
> To: IETF-Announce <[e-mail]>
> Cc: [e-mail]; [e-mail]; [e-mail];
> [e-mail]; [e-mail]
> Subject: [Bier] Last Call: <draft-ietf-bier-tether-04.txt> (Tethering A BIER
> Router To A BIER incapable Router) to Proposed Standard
> 
> 
> The IESG has received a request from the Bit Indexed Explicit Replication WG
> (bier) to consider the following document: - 'Tethering A BIER Router To A
> BIER incapable Router'
>   <draft-ietf-bier-tether-04.txt> as Proposed Standard
> 
> The IESG plans to make a decision in the next few weeks, and solicits final
> comments on this action. Please send substantive comments to the
> [e-mail] mailing lists by 2024-02-29. Exceptionally, comments may
> be sent to [e-mail] instead. In either case, please retain the beginning
> of the Subject line to allow automated sorting.
> 
> Abstract
> 
> 
>    This document specifies optional procedures to optimize the handling
>    of Bit Index Explicit Replication (BIER) incapable routers, by
>    attaching (tethering) a BIER router to a BIER incapable router.
> 
> 
> 
> 
> 
> The file can be obtained via
> https://datatracker.ietf.org/doc/draft-ietf-bier-tether/
> 
> 
> The following IPR Declarations may be related to this I-D:
> 
>    https://datatracker.ietf.org/ipr/3331/
> 
> 
> 
> 
> 
> 
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