I have cisco 1720 router that was previously installed with a serial interface. The router is used to connect to an ISP leased line. As the ISP changed his equipment, I now need to install a WIC-4ESW 4-Port into my router. So I would like to know which ios version I would exactly need in order to have the card recognized and working. I also need to be able to configure encapsulation.
Thx for your help