We have a fax machine at a remote office that is consistently ringing with a standard busy.

If you dial the 10 digit number, it will ring, indicating the telco is delivering the call and then go immediately to a standard busy signal.

As of right now, the fax line is plugged into the analog lines directly and working just fine. However, when I dial the internal extension, it still rings busy.

The router has been rebooted and the gateway has been reset multiple times. Several calling search spaces tried as well.

When I place this extension on my phone, it rings in and out with no issues. However, I do use a different CSS. The credit card machine, which uses the same CSS as the fax works fine when dialing the internal number.

Ideas? I'm at a loss on this one. TIA!

System is CM6.1.2