Re: [Isis-wg] [Bier] WGLC: draft-ietf-bier-isis-extensions-04

["Acee Lindem (acee)" <[e-mail]>]

With respect to the text in section 5.2, I agree with Peter.

Thanks
Acee 

On 2/12/18, 9:59 AM, "BIER on behalf of Peter Psenak (ppsenak)" <[e-mail] on behalf of [e-mail]> wrote:

    Hi Tony,
    
    OSPF does not have the original text, so it does not need the new one.
    
    IMHO, the text in section 5 of ISIS BIER draft suits better to the BIER 
    architecture draft than to the IGP extension draft.
    
    thanks,
    Peter
    
    
    On 09/02/18 20:17 , Tony Przygienda wrote:
    > Sure ;-)  let me ping Peter @ the bottom then ... I don't think any of
    > the stuff applies to OSPF (was ISIS nits) except we can consider an
    > encaps paragraph. We basically suggest both to replace in ISIS the
    > encaps section like this
    >
    > before:
    >
    > "
    >     All routers in the flooding scope of the BIER TLVs MUST advertise the
    >     same encapsulation for a given <MT,SD>.  A router discovering
    >     encapsulation advertised that is different from its own MUST report a
    >     misconfiguration of a specific <MT,SD>.  All received BIER
    >     advertisements associated with the conflicting <MT, SD> pair MUST be
    >     ignored.
    >
    > "
    >
    > now
    >
    > "
    >
    >     Multiple encapsulations MAY be advertised/supported for a given
    >     <MT,SD>.  Clearly, however, there MUST be at least one encapsulation
    >     type in common in order for a BIER encapsulated packet to be
    >     successfully forwarded between two BFRs.
    >
    > "
    >
    > I do think that OSPF would benefit from adding this section to clarify
    > the issue which is not theoretical now that we have Ethernet.
    >
    >
    > So Peter, any ETA on outstanding OSPF nits now that we're tying up the
    > IETF LC?
    >
    > thanks
    >
    > --- tony
    >
    >
    > On Fri, Feb 9, 2018 at 11:12 AM, Greg Shepherd <[e-mail]
    > <mailto:[e-mail]>> wrote:
    >
    >     No I didn't. Why would I? These are the changes you and Les worked
    >     out. I assumed you'd share them as needed. If for some reason you're
    >     uncomfortable engaging with the OSPF draft thread and authors with
    >     your proposed changes, let me know and I'll broker the conversation.
    >
    >     Greg
    >
    >     On Fri, Feb 9, 2018 at 11:04 AM, Tony Przygienda
    >     <[e-mail] <mailto:[e-mail]>> wrote:
    >
    >         Les has the diff, I'd expect him to publish any minute to the
    >         list ... The encaps was a real defect, the rest is just
    >         tightening down the language/spec where it was too loose/too
    >         strict.
    >
    >         OSPF still needs update with conversion TLV removed, same
    >         paragraph on encaps could be useful. I hope Greg pinged Peter ...
    >
    >         thanks
    >
    >         tony
    >
    >         On Fri, Feb 9, 2018 at 10:58 AM, Alia Atlas <[e-mail]
    >         <mailto:[e-mail]>> wrote:
    >
    >             On Fri, Feb 9, 2018 at 12:46 PM, Tony Przygienda
    >             <[e-mail] <mailto:[e-mail]>> wrote:
    >
    >                 Went last nits with Les, we found one issue (encaps
    >                 section was wrong, need to look @ OSPF as well) and
    >                 basically tightened language in few places.
    >
    >
    >             K - please get that  out with the details of changes to the
    >             list.  I did my AD review back in Oct and looked at the
    >             differences before issuing
    >             IETF Last Call.
    >
    >             I look forward to reviewing the minor changes.
    >
    >             Regards,
    >             Alia
    >
    >                 tony
    >
    >                 On Tue, Feb 6, 2018 at 3:45 PM, Greg Shepherd
    >                 <[e-mail] <mailto:[e-mail]>> wrote:
    >
    >                     Thanks Les.
    >
    >                     Any other feedback? Looks like the concerns have
    >                     been addressed. Speak now.
    >
    >                     Cheers,
    >                     Greg
    >
    >                     On Thu, Feb 1, 2018 at 7:26 AM, Les Ginsberg
    >                     (ginsberg) <[e-mail]
    >                     <mailto:[e-mail]>> wrote:
    >
    >                         Greg –____
    >
    >                         __ __
    >
    >                         This thread is outdated.____
    >
    >                         In V6 of the draft we removed the restriction to
    >                         limit IS-IS BIER support to area boundaries – so
    >                         Toerless’s comment (and my proposed text) are no
    >                         longer relevant.____
    >
    >                         __ __
    >
    >                         Specifically:____
    >
    >                         __ __
    >
    >                         Section 4.1:____
    >
    >                         __ __
    >
    >                         “At present, IS-IS support for a given BIER
    >                         domain/sub-domain is ____
    >
    >                                             limited to a single area -
    >                         or to the IS-IS L2 sub-domain.”____
    >
    >                         __ __
    >
    >                         The above text was removed.____
    >
    >                         __ __
    >
    >                         Section 4.2____
    >
    >                         __ __
    >
    >                         o  BIER sub-TLVs MUST NOT be included when a
    >                         prefix reachability____
    >
    >                                advertisement is leaked between levels.____
    >
    >                         __ __
    >
    >                         Was changed to____
    >
    >                         __ __
    >
    >                         o  BIER sub-TLVs MUST be included when a prefix
    >                         reachability____
    >
    >                                advertisement is leaked between levels.____
    >
    >                         __ __
    >
    >                         This aligns IS-IS and OSPF drafts in this
    >                         regard.____
    >
    >                         __ __
    >
    >                              Les____
    >
    >                         __ __
    >
    >                         *From:*Greg Shepherd [mailto:[e-mail]
    >                         <mailto:[e-mail]>]
    >                         *Sent:* Thursday, February 01, 2018 2:23 AM
    >                         *To:* Toerless Eckert <[e-mail]
    >                         <mailto:[e-mail]>>
    >                         *Cc:* Les Ginsberg (ginsberg)
    >                         <[e-mail]
    >                         <mailto:[e-mail]>>; Tony Przygienda
    >                         <[e-mail]
    >                         <mailto:[e-mail]>>; Hannes Gredler
    >                         ([e-mail] <mailto:[e-mail]>)
    >                         <[e-mail] <mailto:[e-mail]>>;
    >                         [e-mail] <mailto:[e-mail]>;
    >                         [e-mail] <mailto:[e-mail]> list
    >                         <[e-mail] <mailto:[e-mail]>>;
    >                         Christian Hopps <[e-mail]
    >                         <mailto:[e-mail]>>
    >
    >
    >                         *Subject:* Re: [Bier] WGLC:
    >                         draft-ietf-bier-isis-extensions-04____
    >
    >                         __ __
    >
    >                         Have these changes been reflected in the draft?
    >                         We're in WGLC but this discussion needs to come
    >                         to a conclusion so we can progress. ____
    >
    >                         __ __
    >
    >                         Greg____
    >
    >                         __ __
    >
    >                         On Tue, Jul 25, 2017 at 12:52 PM, Toerless
    >                         Eckert <[e-mail] <mailto:[e-mail]>>
    >                         wrote:____
    >
    >                             Thanks, Less, that would be lovely!
    >
    >                             I didn't check the OSPF draft, if its
    >                             similar state, explanatory text wold equally
    >                             be appreciated.____
    >
    >
    >                             On Sun, Jul 23, 2017 at 11:28:08PM +0000,
    >                             Les Ginsberg (ginsberg) wrote:
    >                              > Toerless -
    >                              >
    >                              > I am thinking to add a statement in
    >                             Section 4.1 - something like:
    >                              >
    >                              > "At present, IS-IS support for a given
    >                             BIER domain/sub-domain is limited to a
    >                             single area - or to the IS-IS L2 sub-domain."
    >                              >
    >                              > If you believe this would be helpful I
    >                             will spin a new version (subject to
    >                             review/agreement from my co-authors).
    >                              >
    >                              >    Les
    >                              >
    >                              >
    >                              > > -----Original Message-----
    >                              > > From: Toerless Eckert
    >                             [mailto:[e-mail] <mailto:[e-mail]>]
    >                              > > Sent: Saturday, July 22, 2017 6:34 AM
    >                              > > To: Les Ginsberg (ginsberg)
    >                              > > Cc: Tony Przygienda; Hannes Gredler
    >                             ([e-mail]
    >                             <mailto:[e-mail]>); Greg Shepherd;
    >                              > > [e-mail] <mailto:[e-mail]>;
    >                             [e-mail] <mailto:[e-mail]>
    >                             list; Christian Hopps
    >                              > > Subject: Re: [Bier] WGLC:
    >                             draft-ietf-bier-isis-extensions-04
    >                              > >
    >                              > > Thanks Les
    >                              > >
    >                              > > When searching various terms in the doc
    >                             to figure out what happens i am not
    >                              > > sure why i missed this one.
    >                              > >
    >                              > > But: IMHO, RFCs can not only be the
    >                             minimum number of words to get a
    >                              > > running implementation. It also needs
    >                             to specify what this implementation
    >                              > > intends to achieve. Otherwise its not
    >                             possible to do a useful review:
    >                              > > The reviewer can to verify whether the
    >                             spec will achieve what it claims to
    >                              > > achieve is there no definitionn of what
    >                             it claims to achieve.
    >                              > >
    >                              > > If i understand ISIS correctly, my
    >                             reverse engineering of the intent is:
    >                              > >
    >                              > > - BIER TLVs stay within single ISIS
    >                             areas. BFIR and BFER must therefore be
    >                              > >   in the same ISIS area: There is no
    >                             inter-area BIER traffic possible
    >                              > >   with this specification. This is also
    >                             true for ISIS area 0.
    >                              > >
    >                              > > - The same BIER sub-domain identifiers
    >                             can be re-used
    >                              > >   across different ISIS areas without
    >                             any current impact. If these BFR-IDs
    >                              > >   are non-overlapping, then this would
    >                             allow in the future to create a single
    >                              > >   cross ISIS area BIER sub-domain by
    >                             leaking TLVs for such a BIER sub-domain
    >                              > >   across ISIS levels. Leakage is
    >                             outside the scope of this specificication.
    >                              > >
    >                              > > I actually even would like to do the
    >                             following:
    >                              > >
    >                              > > - If BIER sub-domains are made to span
    >                             multiple ISIS areas and BFR-ids
    >                              > > assignemtns
    >                              > >   are made such that all BFR-ids with
    >                             the same SI are in the same ISIS ara,
    >                              > >   then it should be in the future
    >                             reasonably easy to create inter-area BIER
    >                              > >   not by leaking of the BIER TLV but by
    >                             having BFIR MPLS unicastBIER packets
    >                              > >   for different SIs to an appropriate
    >                             L2L1 BFIR that is part of the destination
    >                              > > area/SI.
    >                              > >   (if you would use SI number that are
    >                             the same as ISIS area numbers then
    >                              > >    you could probably do this without
    >                             any new signaling. Not quite sure if
    >                              > >    you can today easily find L1L2
    >                             border router for another area via existing
    >                              > >    TLVs).
    >                              > >
    >                              > >   Alas, this idea will probably be
    >                             killed because of the BIER architecture
    >                              > >   intent not to engineer SI assignments
    >                             in geographical fashions to
    >                              > >   minimize traffic duplication in the
    >                             presence of multiple SIs.
    >                              > >
    >                              > > Cheers
    >                              > >     Toerless
    >                              > >
    >                              > > On Sat, Jul 22, 2017 at 06:03:53AM
    >                             +0000, Les Ginsberg (ginsberg) wrote:
    >                              > > > Tony/Toerless ???
    >                              > > >
    >                              > > > There is an explicit statement as to
    >                             scope:
    >                              > > >
    >                              > > > <snip>
    >                              > > > Section 4.2
    >                              > > > ???
    >                              > > >    o  BIER sub-TLVs MUST NOT be
    >                             included when a prefix reachability
    >                              > > >       advertisement is leaked between
    >                             levels.
    >                              > > > <end snip>
    >                              > > >
    >                              > > > Tony seems to have forgotten that we
    >                             had a discussion about how BIER
    >                              > > might be supported across areas and the
    >                             conclusion was we did not know
    >                              > > how to do that yet.
    >                              > > > (Sorry Tony)
    >                              > > >
    >                              > > > Note this is ???consistent??? with
    >                             https://www.ietf.org/id/draft-ietf-bier-
    >                             <https://www.ietf.org/id/draft-ietf-bier->
    >                              > > ospf-bier-extensions-07.txt Section
    >                             2.5<https://www.ietf.org/id/draft-ietf-
    >                             <https://www.ietf.org/id/draft-ietf->
    >                              > >
    >                             bier-ospf-bier-extensions-07.txt%20Section%202.5>
    >                             - which limits the
    >                              > > flooding scope of BIER information to a
    >                             single area unless it can be validated
    >                              > > that the best path to the prefix with
    >                             BIER info can be validated to be to a
    >                              > > router which itself advertised the BIER
    >                             info. This is not something IS-IS can do
    >                              > > since a single IS-IS instance only
    >                             supports one area and therefore does not
    >                              > > have the Level-1 advertisements of the
    >                             originating router when that router is
    >                              > > in another area.
    >                              > > >
    >                              > > > A few more responses inline.
    >                              > > >
    >                              > > > From: BIER
    >                             [mailto:[e-mail]
    >                             <mailto:[e-mail]>] On Behalf Of
    >                             Tony Przygienda
    >                              > > > Sent: Friday, July 21, 2017 5:17 AM
    >                              > > > To: Toerless Eckert
    >                              > > > Cc: Hannes Gredler ([e-mail]
    >                             <mailto:[e-mail]>); Greg Shepherd;
    >                             [e-mail] <mailto:[e-mail]>;
    >                              > > > [e-mail]
    >                             <mailto:[e-mail]> list; Christian Hopps
    >                              > > > Subject: Re: [Bier] WGLC:
    >                             draft-ietf-bier-isis-extensions-04
    >                              > > >
    >                              > > > Terminology is a bit nits  IMO since
    >                             the doc is reading clear enough for
    >                              > > someone who read BIER & ISIS. I can
    >                             reread it or Les can comment whether
    >                              > > we should tighten glossary ...
    >                              > > >
    >                              > > > With the scope I agree, that got lost
    >                             and the doc should be possibly rev'ed
    >                              > > before closing LC. Yes, we flood AD
    >                             wide was the agreement but something
    >                              > > mentioning that this could change in
    >                             the future is good so we are forced to
    >                              > > give it some thought how that would
    >                             transition ...
    >                              > > >
    >                              > > > Thinking further though, in ISIS we
    >                             have a clean document really. The  BIER
    >                              > > sub-TLVs go into well defined TLVs in
    >                             terms of flooding scope. Normal L1-L2
    >                              > > redistribution can be used to get the
    >                             info to all needed places AFAIS. So
    >                              > > maybe nothing needs to be written. I
    >                             wait for Les to chime in.
    >                              > > >
    >                              > > > OSPF I would have to look @ scopes
    >                             again & think whether we need to
    >                              > > write something or maybe Peter can
    >                             comment ...
    >                              > > >
    >                              > > > --- tony
    >                              > > >
    >                              > > >
    >                              > > >
    >                              > > > On Fri, Jul 21, 2017 at 8:27 AM,
    >                             Toerless Eckert
    >                              > > <[e-mail]
    >                             <mailto:[e-mail]><mailto:[e-mail]
    >                             <mailto:[e-mail]>>> wrote:
    >                              > > > Sorry, past the two weeks, but
    >                             hopefully  benign textual comments:
    >                              > > >
    >                              > > > We tried to find an explicit
    >                             statement about the scope of BIER TLVs - eg:
    >                              > > > are they meant to stay within an
    >                             area, have some redistribution across
    >                              > > > areas/levels or not.
    >                              > > >
    >                              > > > Tony said WG agreement was to have
    >                             these TLV be flooded across the
    >                              > > > whole ISIS domain for now (this
    >                             draft). So an explicit statement to that
    >                              > > effect would
    >                              > > > be great (All BIER sub-domains TLVs
    >                             are flooded across all ISIS areas/levels,
    >                              > > so they span the whole ISIS domain).
    >                              > > >
    >                              > > > Also, if future work may/should could
    >                             improve on that maybe some
    >                              > > > sentence about that (i guess one
    >                             could just have ISIS intra-area BIER sub-
    >                              > > domains ?).
    >                              > > >
    >                              > > > Also: Do a check about possible
    >                             ambiguity of any generic terms like
    >                              > > sub-domain, level, area, topology so
    >                             that reader that don't know the
    >                              > > terminology ofall protocols (ISIS,
    >                             BIER) by heart can easily know which
    >                              > > protocol is referred to.
    >                              > > >
    >                              > > > [Les:] There is no mention of
    >                             ???level??? in the document.
    >                              > > > The use of ???sub-domain??? is
    >                             clearly always associated with ???BIER???.
    >                              > > > ???topology??? is always used as an
    >                             RFC 5120 topology ??? therefore
    >                              > > clearly an IS-IS topology.
    >                              > > > There is only one use of the term
    >                             ???area??? (in Section 5.1). That text
    >                              > > might deserve a bit of clarification
    >                             given this might be either a Level 1 area or
    >                              > > the Level2 sub-domain. I???ll take a
    >                             pass at it.
    >                              > > > (BTW ??? I am talking about IS-IS
    >                             area/L2sub-domain Toerless. ???)
    >                              > > >
    >                              > > > I don???t see that any other
    >                             clarification is needed ??? but Toerless ??? if
    >                              > > you can point to any specific
    >                             sentences/paragraphs which you find confusing
    >                              > > - I???ll take a second look.
    >                              > > >
    >                              > > >    Les
    >                              > > >
    >                              > > >
    >                              > > > I guess there are no BIER level, area
    >                             or topologies, but still makes
    >                              > > > reading easier if the doc would say
    >                             "ISIS level", "ISIS area", or at
    >                              > > > least have them in the Terminology
    >                             section. And probably in
    >                              > > > terminology say "domain -> in the
    >                             context of this document the BIER
    >                              > > domain which is also the same as the
    >                             ISIS domain"
    >                              > > > (which i hope is the correct
    >                             statement, see above).
    >                              > > >
    >                              > > > Cheers
    >                              > > >     Toerless
    >                              > > >
    >                              > > >
    >                             _______________________________________________
    >                              > > > BIER mailing list
    >                              > > > [e-mail]
    >                             <mailto:[e-mail]><mailto:[e-mail]
    >                             <mailto:[e-mail]>>
    >                              > > >
    >                             https://www.ietf.org/mailman/listinfo/bier
    >                             <https://www.ietf.org/mailman/listinfo/bier>
    >                              > > >
    >                              > > >
    >                              > > >
    >                              > > > --
    >                              > > > We???ve heard that a million monkeys
    >                             at a million keyboards could
    >                              > > produce the complete works of
    >                             Shakespeare; now, thanks to the Internet,
    >                              > > we know that is not true.
    >                              > > > ???Robert Wilensky
    >                              > >
    >                              > > --
    >                              > > ---
    >                              > > [e-mail] <mailto:[e-mail]>____
    >
    >                         __ __
    >
    >
    >
    >
    >                 _______________________________________________
    >                 BIER mailing list
    >                 [e-mail] <mailto:[e-mail]>
    >                 https://www.ietf.org/mailman/listinfo/bier
    >                 <https://www.ietf.org/mailman/listinfo/bier>
    >
    >
    >
    >
    >
    >
    >
    > _______________________________________________
    > BIER mailing list
    > [e-mail]
    > https://www.ietf.org/mailman/listinfo/bier
    >
    
    _______________________________________________
    BIER mailing list
    [e-mail]
    https://www.ietf.org/mailman/listinfo/bier