concern over public peering points

Mon Jul 5 11:02:37 UTC 2004

* scg at gibbard.org (Steve Gibbard) [Mon 05 Jul 2004, 10:19 CEST]:
[..]
> The performance arguments are probably more controversial.  The
> arguments are that shortening the path between two networks increases
> performance, and that removing an extra network in the middle increases
> reliability. The first argument holds relatively little water, since
> it's in many cases only the AS Path (not really relevant for packet
> forwarding performance) that gets shortened, rather than the number of
> routers or even the number of fiber miles.

"Not really"?  Not always, perhaps.  But it's more the rule than the
exception, I think.

> If traffic goes from network A, to network A's router at an exchange
> point, to network C, that shouldn't be different performance-wise from
> the traffic going from network A, to Network B's router at the exchange
> point, to Network C.

Except that, due to "peering games" some companies tend to engage in,
the exchange point where A and B exchange traffic may well be in a
different country from where A, C and their nearest exchange point is.

> Assuming none of the three networks are underprovisioning, the
> ownership of the router in the middle shouldn't make much difference.
> The reliability argument is probably more valid -- one less network
> means one less set of engineers to screw something up, but the big
> transit networks tend to be pretty reliable these days, and buying
> transit from two of them should be quite safe.

The correct phrasing is indeed "one less network" and not "one less
router."  It's rarely one device in my experience.

	-- Niels.