Re: [babel] Mirja Kühlewind's Discuss on draft-ietf-babel-rfc6126bis-12: (with DISCUSS and COMMENT)

[Juliusz Chroboczek <[e-mail]>]

Dear Mirja,

> I keep pointing at RFC8085 because that’s what the IETF agreed to be
> “safe” in the general case.

I refer you to my mail of 9 August 2019, where I reply to almost exactly
the same statement.  RFC 8085 discusses what is considered recommended for
protocols that run over the Internet.  To witness:

   Internet paths can have widely varying characteristics, including
   transmission delays, available bandwidths, congestion levels,
   reordering probabilities, supported message sizes, or loss rates.
   Furthermore, the same Internet path can have very different
   conditions over time.

In Babel, like in OSPF, there is no "Internet path" involved -- there is
just an association between two direct neighbours (from the point of view
of layer 3).  It is therefore my opinion -- already stated in my mail of
August 9 --, that obeying the recommendations in RFC 8085 is not required
for Babel to become PS.

In the same mail of 9 August 2019, I make the claim that there is no
mechanism related to RFC 8085 in RFC 5340.  In other words, it would
appear that you are holding Babel to a much higher standard than OSPFv.

If that is the case, then I request that you state explicitly why you
think that Babel must be held to a much higher standard than OSPFv3.  If
that is not the case, then please clear your discuss.

> Currently the document proposes some values but it does not discuss in
> which scenario these values are appropriate to use (or when they are not
> appropriate to use anymore).

Appendix B gives values that are suggested for implementations.

> If you have that experience it should be possible to e.g. to describe
> the network scenario that you used babel in and give the values that
> have been used in that scenario. What are those scenarios?

The first set of parameters in Appendix B gives the values that are used
by recent versions of babeld (the reference implementation of Babel) and
that have been used in production for many years in a wide range of
networks, including wifi meshes, wired networks, and large community
networks consisting of a complex mixture of wireless and wired links.
These scenarios are described in the Applicability statement.

-- Juliusz