I've a 1721 cisco router and I need to purchase to my ISP (Telefonica Spain) a point to point conection to internet.
What kind of wic have I need to purchase?
since its a point to point (T1) link its limited only to 1.5 Mbps you can make use of that 1.5 Mbps bandwidth alone.
you wont be able to add or remove any channels on this module.
if you want to upgrade the existing bandwidth from 1.5 Mbps then you will have to add up one more module or go with WIC-2T and 2*T1's which can support 2*1.5Mbps ..