The problem of accessing the Internet via dial-up

[ofy]

I just got a Motorola phone and hooked it up via data cable to Windows XP. Xp shows no problem seeing it or controlling it. When I use the dialup feature (so I can get on the internet), it dials (the phone screen states it's dialing too), but almost instantly I hear a "error" tone on the phone and XP comes back with a 678 error - remote computer not responding. I know it's something simple (well.. I hope). Ideas?