Digiboard Drops DTR After Disconnect

When a client disconnects from a RAS server, the DTR line on the Digiboard COM port may not return. Because the modem is not reset, no additional calls can come in on that port. If a client attempts to dial in, the modem picks up the line, but the RAS server does not respond. As a result, the client receive a 640 error message. The RAS server does not log any errors in the event log, but the RAS Administrators tool show that the port has been disconnected and is not ready.

These symptoms will appear only after the RAS server has been in operation for some time. Stress tests indicate that several hundred inbound calls are needed to produce the problem.

There is a problem in the Digiboard DIGIFEP5.SYS driver.

Microsoft has confirmed this to be a problem Windows NT version 3.5.