External ISDN Router

[ali.asghar]

I have a customer who has Cisco 2620 routers between corporate and branch running Point to Point T1. The already have external ISDN router, and just wants to terminate to Cisco 2621-xm router as a backup. They don't want to spend any money to buy an ISDN card for Cisco 2621-XM router.

An ISDN router supports V.35 port, and am thinking all I need for 2621 router is (1) Serial Port Card. Am I correct?

Do I have to do any special config for 2621 router?

[dgahm]

If you want to use a serial port you will need an external ISDN terminal adapter. It would be cheaper and easier to buy a BRI U interface WIC for your router.