url_cisco

Understanding 2-Port Serial WAN Interface Card (WIC-2T)
http://www.cisco.com/en/US/products/hw/routers/ps274/products_tech_note09186a00800b0858.shtml#intro


2-Port Async/Sync WAN Interface Card (WIC-2A/S)
http://www.cisco.com/warp/public/107/wic-2as.shtml