The US Robotics modems that were donated to WICEN cannot distinguish correctly between ring tone and busy tone. They therefore return “Busy” when the phone number they are dialing rings. Peter Thorp has produced a document describing how to overcome this problem.
As supplied, the modem is capable of speeds up to 33k6 Baud, however it can be upgraded to 56k by running this patch software. Click here for instructions.