Webuser Forums: Wiring problem connecting modem

I tried to connect my modem to a BT phone line, but the modem couldn't detect a signal (couldn’t detect dial tone, or make call). It turns out that changing the modem cable solved the problem.

I tried several cables. It turns out that some of the cables would work only with the phone and not with the modem. Other cables would work only with the modem and not with the phone.

I tried several phones, and several modems; all had the same result.

I took a couple of the cables to another house, where they worked fine in both a phone and in a modem.

So, my question is: what's going on?

I assume that there is come difference between the cables that work in the phones, versus the ones that work in the modem; perhaps some have 4 wires and others have 2. But even so, I can't understand why I should get different results in different houses.

Any insight would be much appreciated.

colin..