We have a 3745 that's connected to a T-1 and a cable modem. Heavy inbound/outbound traffic to either ISP is slowing traffic through the router which in turn affects browsing, Citrix, etc. Ping times go from 50ms to 300-400ms or greater. The odd thing is that the router CPU is not busy (<10%, usually 2-3%), the interfaces show no errors, and there's no obvious signs (to me) that the router is overworked at all. I've gone through Performance Tuning Basics (doc 12809) with no improvement.
The router terminates about 15 VPN's with very little traffic on them. We have NAT setup using multiple pools and route-maps.
I can post relevant parts of the config here if I know what would be helpful.
What am I missing??