How do you determine the HW limitation for 2800 Series routers ? I cannot seem to find any related docs for this.
Would a 2811 Router be able to handle upton 4.5Mbps of WAN traffic (Using 3 WICs) ?
This link gives approximate performance levels for the routers in the 2800 family:
According to table 1 the 2811 will handle 2 T1s. To handle 3 T1s it looks like you would want a 2821.