Re: [babel] About BIER in Babel

[Alia Atlas <[e-mail]>]

Pierre,

Just to clarify - of course the bier over IPv6 is an interesting draft that
the WG has discussed - in some aspects extensively.  There were also
aspects that needed consultation with 6man.  It is still an individual
draft.

I'm glad to hear about the implementation, of course. :-)

Regards,
Alia

On Tue, Mar 28, 2017 at 11:50 PM, Pierre Pfister <[e-mail]>
wrote:

> Hello Alia and Dave,
>
> Le 28 mars 2017 à 18:06, Alia Atlas <[e-mail]> a écrit :
>
> Hi Dave,
>
> Take a look at https://datatracker.ietf.org/doc/html/draft-ietf-bier-
> architecture
> and https://datatracker.ietf.org/doc/html/draft-ietf-bier-
> mpls-encapsulation.
> The latter allows use over Ethernet (despite the old draft title).  The
> IPv6 encapsulation does not have WG agreement to adopt and wasn't discussed
> this IETF.
>
>
> It was not discussed this IETF indeed, but was discussed the ietf before,
> and very extensively during the design team meeting. I wouldn't dare
> contradicting the responsible AD, but although we can objectively say that
> the document hasn't been adopted (he has been presented only once), saying
> that it has no "WG agreement" is more prone to discussion. I would be happy
> to see more discussion on BIER ML about that.
>
> Anyway... More interesting information for Dave inlined ...
>
>
> Regards,
> Alia
>
> On Tue, Mar 28, 2017 at 5:48 PM, Dave Taht <[e-mail]> wrote:
>
>> ... up until this moment I was mostly ignorant of bier. I may well
>> still be overly ignorant, but read on.
>>
>> On Tue, Mar 28, 2017 at 1:47 PM, Juliusz Chroboczek <[e-mail]> wrote:
>> > Dear Sandy, dear all,
>> >
>> > I think there are very good reasons why it would be interesting to
>> > experiment with BIER and Babel.  As you explained, there are at least
>> two
>> > approaches worth considering:
>> >
>> >   - announce BIER routing directly in Babel, as your draft suggests;
>> >   - use MLD with Babel.
>> >
>> > I am not competent to judge which approach is suitable, but it is
>> clearly
>> > attractive to run a single protocol.
>> >
>> > As I mentioned at the mike, there are a number of problems with your
>> > encoding.  My personal intuition would be to use a new AE number for
>> BIER,
>> > but of course someone would need to write it down and check the details.
>>
>> However, leveraging this encoding over the others in the core draft seems
>> straightforward to encapsulate into an ae with no afteraffects
>> elsewhere in babel.
>>
>> https://datatracker.ietf.org/doc/html/draft-pfister-bier-over-ipv6
>>
>> 4096 bits (maximum requirement for bier), on the other hand, breaks
>> everything (babel mtu requirement while still fitting in everything
>> else),
>>
>> while (the minimum requirement) of 256 bits may well look a lot like
>> how the new source specific ae is formed.
>>
>
> 256 is the minimum requirement for BIER over MPLS and Ethernet.
> There was discussion and, IMHO, consensus, that the minimum bit-string
> length
> requirement would depend on the encap used.
> Obviously, in the case of bier-over-ipv6, 256 doesn't make sense. 4096
> even less so.
> Using BIERoIPv6, bitstring lengths between 32 and 64 are more reasonable.
>
>
>> if there are other docs in that wg worth reading, running code on
>> linux, or other use cases, please point me at em!
>>
>
> I implemented a very rudimentary version of BIERoIPv6 a while ago, for
> testing and learning purposes:
> https://github.com/Oryon/bier6
>
> But this implementation has nothing to do with Babel, or Zhang's proposal.
>
> Cheers,
>
> - Pierre
>
>
>> > As David mentioned, some of us would feel much more comfortable if there
>> > were a prototype implementation before we are asked to adopt your draft.
>> > I would be interested in helping, but I have neither the competence nor
>> > the manpower to do the implementation on my own.
>> >
>> > -- Juliusz
>> >
>> > _______________________________________________
>> > babel mailing list
>> > [e-mail]
>> > https://www.ietf.org/mailman/listinfo/babel
>>
>>
>>
>> --
>> Dave Täht
>> Let's go make home routers and wifi faster! With better software!
>> http://blog.cerowrt.org
>>
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>>
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