T3 or not to T3

Yeah, definately. But most backbones seem to have "customer routes" as
an option, and if I trust them enough to get those routes correct then
I will hopefully not have to bother with extreme amounts of filtering.
It's pretty easy to enforce "no transit" at the packet filtering level
-- only packets destined for my nets will be allowed in. Is there some
other aspect of filtering I'm forgetting about? We have a dedicated
and backup network engineer at any rate. The border router would be a
cisco 7200 or 7500 series with 128Mb.


Is this really how people enforce "no transit"? I have been told that packet
filtering is quite cpu expensive. I would think that packet filtering on a
router that is probably already overburdened is not an attractive solution.