[tech] WAIX Routing ETA

[Adrian Chadd]

On Tue, Mar 01, 2005, Paul Day wrote:

> >theoretical WAIX peer 'DodgyNet' messed up it's router config, and 
> >ignored the advertisements from WAIX, everything could seem fine (routes 
> >being advertised, outbound traffic from UCC goes via WAIX), but the data 
> >going back to UCC could be via a charged link.
> 
> Unlike most, I thought parnet classed incoming traffic as free or charged 
> based on its outbound route, rather than its inbound route?

Its all a bit strange. Specifically, yes, Parnet bill us on traffic based
on the destination route they have for the given subnet. This makes the
rather evil assumption that traffic is symmetric. It isn't /always/
symmetric, as Paul has found out from time to time :), but the amount
of traffic under normal circumstances that is mis billed is almost always
under the noise floor[1].

Answering Davyd: yes, the traffic from internet-2 and whatnot is 'free',
but here's the catch - most of it comes in the same interface (Parnet)
as the bulk of our traffic. The only time this isn't the case is if it
comes in via our link to GrangeNet. The reason that traffic over GrangeNet
isn't free is because the internet isn't a stable place and we don't want/need
people whinging at us because traffic is free one day and isn't free the next.
People /will/ want to start transferring huge, huge bulk amounts of traffic
to and from free sites. Yes, legitimate stuff.

There's solutions to this but it would require re-engineering of the core.
I won't go into examples, I'm sure the Clueful out there know what could be
done with a network full of Cisco switch/routers. And that won't happen
just to make this 'free' network stuff work. We want it, but it'll be part
of a general re-engineering when we start shoe-horning in Quality of Service(tm).

In short: I'm sorry guys, but as much as I'd love the university to be able
to tell that traffic is indeed free when we bloody get it and be able to
communicate this effectively out to our edge devices which also do filtering,
its Just Not Easily Possible Right Now Without Exposing Us To Lots Of Shit,
and therefore won't happen unless Grahame, Toivo or I invent some 5 minute
hack that'll last 3 months before breaking. See if you can simply come up
with an alternative. :)




Adrian

[1] Noise floor: defined (by me) as the constant chatter you hear on todays
    internet by viruses, blackhat scans, stupidly configured DNS and other
    such tripe.