[c-nsp] How many DSL L2TP-tunnels on a 3825?

[Garry]

I'm currently looking into a replacement for our redundant set of 7200 
routers (non-VXR) that are doing our DSL l2tp-Tunnels ... currently, 
both routers run at around 20-25% CPU load (peak). We possibly will get 
a large batch of additional dial-ins soon, which would probably be too 
much for the two to handle (especially should one of the two fail), so I 
thought about getting two 3825 to replace them - the two GBit-ethernets 
on the routers being a big plus.

How many real life DSL sessions should I expect a single 3825 to handle 
comfortably w/o performance issue? Dialups are a healthy mix of anything 
between 1M/128k through 6M/512k, with some percentage of SDSL in between 
(2M)

Thanks for you input, -garry