Jack

There are several things that it would be nice to know to make a recommendation. Things like how many upstream peers do you anticipate, how many downstream peers? Do you anticipate taking full routes from your upstream peers? How many interfaces and what kind of interfaces will you need?

Without knowing those details I would offer this advice: I would probably start looking at the 7200 router line (it has good control plane processing capability, has capacity for plenty of memory, it has a good variety of interface speeds and feeds). You could also probably do it on 3800 gear. You might be able to do it on 2800 depending on how many peers, and full/partial views.

HTH

Rick

I'm going to emphasis a point made by Edison and Rick; very much depends on what you're planning to do with Internet BGP. This will greatly determine what's an acceptable router.

For example, sufficient RAM is crucial. So, a 2801 that might otherwise be acceptable, wouldn't be because of its maximum RAM capacity.

Often you choose a router's minimal performance level on the size of the WAN circuits. Here again, working with large BGP tables places load on the router. So, a 2821 that you might have used to drive a couple of T-1s, might need to be "upsized" to a 3800 model; likewise T-3 on a 3845 might need 72xx.

If you can get by on few interfaces or modules slots, the new 7201 is attractive as is the older 7301. Although it works against minimal expense, consider something like one 7201 per BGP peer. (Otherwise if you multi-home to same box, single box crash drops you off the Internet.)