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

[Toerless Eckert <[e-mail]>]

Thanks, Huaimo, inline

On Mon, Aug 15, 2022 at 03:20:29PM +0000, Huaimo Chen wrote:
> A)
> 
> > No Sub-Sub-TLV is defined so far.
> 
> are ?
> [HC]: No Sub-Sub-TLV is defined so far.

I think the correct english is "No Sub-Sub-TLV are defined so far",
or maybe even better "No Sub-Sub-TLV have been defined so far.".

> B)
> [HC]:  The BitPosition assigned to (or configured for) an adjacency of
> the network topology is distributed in the Sub-TLV.
> If the number of adjacencies is greater than 64k in the network,
> it cannot be represented by 16 bits directly.
> I also don't think the BIER/BIER-TE architecture would permit this
> field to be longer than 16 bits, we (BIER/BIER-TE) only support 64k in both.
> [HC]: If BIER-TE architecture does not permit this and only supports 64k
> adjacencies, then the distribution of the bit positions for the adjacencies
> in this draft will follow it.

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

> C) I think the word BitPosition and DrEndBitPosition are not correct.
> 
> What you do seemingly want to encode is what BIER (and RFC8401) calls BFR-id,
> and BIER-TE unfortunately weaseled out giving a new name (unfortunately,
> bfr-id does not make sense for BIER-TE even though the values themselves
> do make equally sense). I guess we should have given it a name like ADJ-id,
> and that is what i would suggest calling this field. Maybe add simple
> explanation:
> 
>    ADJ-id = BitPosition + SI * BSL (like BFR-id in BIER)
> 
> Or else, we can also just call it bfr-id like RFC8401, just noting that
> the semantic of the indicated bit is not that of a BIER bfr-id, but of
> a BIER-TE foward_connected() adjacency.
> 
> In any case, bit position / BitPosition is consistently used in rfc8279 and
> BIER-TE to solely refer to bits within a BitString in a packet (<= 4096), not
> across all the BitString bits spossible for an SD (<= 64k).
> [HC]: This draft just distributes the bit position configured for or assigned to
> an adjacency.

BitPosition in BIER/BIER-TE does not go to 64k, it only goes to 2^BSL, thats
why its IMHO not a good word to use here for this field.

> D) I still don't think i have seen an answer giving an exxample of what
> DrEndBitPosition could be. Still curious.
> [HC]: Draft "BIER-TE for Broadcast Link" describes it in detail.

Please add reference to that draft and refer to that reference in the paragraph
explaining DrEndBitPosition.

Cheers
    Toerless

> On Fri, Jul 29, 2022 at 12:13:19PM -0700, [e-mail] wrote:
> >
> > 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://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-ietf-bier-te-isis%2F&amp;data=05%7C01%7Chuaimo.chen%40futurewei.com%7C18da4fa2fc66453333b908da7c7abbf4%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637959163847747562%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=VcsW5ozVjbFNZIo%2BBxHJPzAuMlM1puXxE0NsRBfA7CI%3D&amp;reserved=0
> >
> > There is also an htmlized version available at:
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fhtml%2Fdraft-ietf-bier-te-isis-01&amp;data=05%7C01%7Chuaimo.chen%40futurewei.com%7C18da4fa2fc66453333b908da7c7abbf4%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637959163847747562%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=TSJ%2BADJv2yT6tcL7UKuCi%2F8t0%2BMYfP%2Fpm7R28KnPHek%3D&amp;reserved=0
> >
> > A diff from the previous version is available at:
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ietf.org%2Frfcdiff%3Furl2%3Ddraft-ietf-bier-te-isis-01&amp;data=05%7C01%7Chuaimo.chen%40futurewei.com%7C18da4fa2fc66453333b908da7c7abbf4%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637959163847747562%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=HtA2iK%2FdNH551QWCSRfkalgkFnGBgxDbCRkV8wb02Nk%3D&amp;reserved=0
> >
> >
> > Internet-Drafts are also available by rsync at rsync.ietf.org::internet-drafts
> >
> 
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