Re: [babel] I-D Action: draft-ietf-babel-rtt-extension-01.txt

[Juliusz Chroboczek <[e-mail]>]

> I’ve given the updated draft a first read. Here are my comments so far.
> Sorry if that’s not the correct approach for submitting a review.

Thanks, and yes, that's the traditional way.  (Some WGs prefer to use
Github, but Babel is traditional.)

>> Since this causes a negative feedback loop, special care is needed to ensure
>> that the resulting network is reasonably stable.

> However, in my understanding a control loop is usually qualified as negative
> if it dampens systems responses and hence promotes stability.

Right.  I'll try to clarify this in -02.

A negative feedback loop dampens response.  In a continuous setting, it
leads to convergence, but in a discrete setting, the fixpoint might not
exist, and therefore the system oscillates around the (nonexistent) fixpoint.

In routing, the continuous setting would imply being able to send the
traffic over multiple paths, and the fixpoint would be something like
"send 2/3 of the traffic the the neighbour A and 1/3 of the traffic to the
neighbour B".  However, we're in the discrete setting, we need to choose
between A and B, and so, the system might fail to converge and keep
oscillating between A and B.

-- Juliusz