Advice on BGP traffic engineering for classified traffic

[jbates at brightok.net (Jack Bates)]

I'm curious if anyone has a pointer on traffic manipulation for 
classified traffic.

Basics, I have a really cheap transit connection that some customers are 
paying reduced rates to only use that connection (and not my other 
transits). Though I've considered support for cases where NSP peering 
disputes break out. While I can advertise their networks out the correct 
transit for return traffic, I still have to figure out how to handle 
egress traffic.

I'm guessing the crux of it is policy routing based on source address, 
but I'm interested in ways to engineer it to easy management and 
scalability. I've considered the possibility of an l3vpn to interconnect 
customers that are not requiring full routes, and possibly some type of 
vpls tunnel terminated at the necessary router for customers who need 
full routes.

Thoughts, pointers, suggestions?


Jack