[Babel-users] [PATCH] babel: Basic support for a version string

Juliusz Chroboczek jch at pps.univ-paris-diderot.fr
Sun Apr 5 12:43:54 UTC 2015

> 1) It is not clear to me how to generate a release tarball with the
> VERSION file, instead of git.

> I bummed the tiny script from the dnsmasq tree to parse the release
> tags and supply the git commit it was based on.

I'll have a look at your patch.

> 2) I thought about adding the version to the info supplied to
> babelweb, but did not poke there


> 3) It is not clear from reading the man page if diversity routing and
> rtt based stuff can be enabled at the same time.

Yes, they can.  Babel doesn't care.

> If both are set, who wins?

They act at different levels, RTT is at the cost level, diversity is at
the metric level.  Picture:

  A -----> B -----> C
    Cost1    Cost2
       \     /
        \   /

Ordinary Babel on wireless links:

  Cost = ETX
  Metric = Cost1 + Cost2

RTT-based Babel on wireless links:

  Cost = ETX + F(RTT)
  Metric = Cost1 + Cost2

where F is the map defined in Fig. 7 of http://arxiv.org/pdf/1403.3488.pdf .


  Cost = ETX
  Metric = α·Cost1 + Cost2

where α depends on whether A-B and B-C interfere or not.

RTT-based Babel-Z:

  Cost = ETX + F(RTT)
  Metric = α·Cost1 + Cost2

So everything should work fine, although I'd expect the behaviour to be
interesting to analyse.

> 4) Also, diversity routing is the default for me, and I would suspect
> the default for others, so I would suggest flipping the default to
> true in 1.6.

Not in 1.6.0.  There's a huge change in 1.6.0, and if we run into
problems, I need to know why.  So the default configuration is not

I also haven't formally evaluated Babel-Z yet (yeah, I know, it's been two
years), so I'm still a little nervous about it.

> Should I use github pull requests instead?

If you do, please mail, I don't log into Github usually.

— Juliusz

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