The splitting of national vs international traffic is an interesting point, and not very common internationally i.e. the people that write the applications that provide traffic calculations don't differentiate the two. Arguably, it is possible to do this with BGP communities; assuming, of course, that both Telecom and Telstra were willing to exchange national routing information at peering points with other providers. Otherwise the split will not be very accurate.

From the perspective of software management, I do know that boxes like the ERX pass traffic accounting information in the form of RADIUS interim accounting records, and as such have absolutely no awareness of traffic paths. In order to do a split, I'd guess that you'd have to come up with a way of reconciling NetFlow data with radius records, and I'm pretty sure that'd be pretty hard to make scalable

Cheers, Gordon