Subject: Re: [babel] Thoughts on rfc6126bis

From: Juliusz Chroboczek <[email-masked]>
Date: Wed, 03 Jan 2018 22:33:00 +0100

> At this point, the whole network must be rebooted in order to solve the
> starvation; this is essentially what EIGRP does when it performs
> a global synchronisation of all the routers in the network with the
> source (the "active" phase of EIGRP).

I've replaced this with:

   The only route available from A to S, the one that goes through B, is
   not feasible: A suffers from spurious starvation.  At that point, the
   whole subtree suffering from starvation must be reset, which is
   essentially what EIGRP does when it performs a global synchronisation
   of all the routers in the sarving subtree (the "active" phase of
   EIGRP).

I don't see any better way of softening this without getting too far into
the details of DUAL's use of the diffusing computation algorithm.  Please
let me know if it's satisfactory for you.

-- Juliusz

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From: Juliusz Chroboczek <[email-masked]>
Date: Wed, 03 Jan 2018 22:52:25 +0100

> As many routing algorithms, Babel computes costs of links between any
> two neighbouring nodes, abstract values attached to the edges between
> two nodes.  We write C(A, B) for the cost of the edge from node A to
> node B.
   
> I think this is probably missing a word? Perhaps "Babel uses an abstract value to represent the cost of the link between any two nodes," or some such?

Rewritten as:

   For every pair of neighbouring nodes A and B, Babel computes an
   abstract value known as the cost of the link from A to B, written
   C(A, B).

I've also merged it with the following paragraph.

> Given a route between any two nodes, the metric of the route is the sum
> of the costs of all the edges along the route.  The goal of the routing
> algorithm is to compute, for every source S, the tree of routes of
> lowest metric to S.

> Because the shortest path is always loop free -- I don't know if this is
> worth mentioning here, but it might be useful for some readers.

If that's okay with you, I'd rather avoid this kind of digression in this
introductory bit.  (The interesting property, actually, is that the set of
shortest paths is a tree.)

-- Juliusz