Re: [Bier] I-D Action: draft-ietf-bier-te-isis-01.txt

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

Some pedantic comments on this draft:

For the new BIER-TE sub-TLV:

1)The relevant registry has been renamed to be "IS-IS Sub-TLVs for TLVs Advertising Neighbor Information". Please use this new name.
https://www.iana.org/assignments/isis-tlv-codepoints/isis-tlv-codepoints.xhtml#isis-tlv-codepoints-advertising-neighbor-information

2)Please do NOT insert padding to keep content aligned on a 4 byte boundary. This may be useful for OSPF, but it is not for IS-IS as TLVs are NOT aligned inside an LSP. All you are doing is wasting space - which is precious in IS-IS given the limited LSP space.

3)You say in Section 2:

"Note that if each of BitPosition
   and DrEndBitPosition uses more than 2 octets, we use 4 or more octets
   for each of them."

I do not see how the receiver of the sub-TLV could tell whether the 2 octet or 4 octet encoding was sent as you have nothing that specifies the length of these fields.
You can't use the total length of the sub-TLV as it could include optional sub-sub-TLVs.

??

4)In IANA section, I do not know why you specified "N" for TLVs 23 and 223.
While RFC 5311 (which defines these TLVs) is not popular, if there was an implementation, I see no reason why it should be invalid to send the BIER-TE info in these TLVs.

Thanx.

    Les


> -----Original Message-----
> From: BIER <[e-mail]> On Behalf Of [e-mail]
> Sent: Friday, July 29, 2022 12:13 PM
> To: [e-mail]
> Cc: [e-mail]
> Subject: [Bier] I-D Action: draft-ietf-bier-te-isis-01.txt
> 
> 
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the Bit Indexed Explicit Replication WG of the IETF.
> 
>         Title           : IS-IS Extensions for BIER-TE
>         Authors         : Huaimo Chen
>                           Mike McBride
>                           Aijun Wang
>                           Gyan S. Mishra
>                           Yanhe Fan
>                           Lei Liu
>                           Xufeng Liu
>   Filename        : draft-ietf-bier-te-isis-01.txt
>   Pages           : 7
>   Date            : 2022-07-29
> 
> Abstract:
>    This document describes IS-IS extensions for distributing
>    BitPositions configured on the links in "Bit Index Explicit
>    Replication Traffic Engineering" (BIER-TE) domain.
> 
> 
> 
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-ietf-bier-te-isis/
> 
> There is also an htmlized version available at:
> https://datatracker.ietf.org/doc/html/draft-ietf-bier-te-isis-01
> 
> A diff from the previous version is available at:
> https://www.ietf.org/rfcdiff?url2=draft-ietf-bier-te-isis-01
> 
> 
> Internet-Drafts are also available by rsync at rsync.ietf.org::internet-drafts
> 
> 
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