From Tsyplakov Maxim V. on 28 Jul 1998
Regard! Help to solve a problem: Beside my ISP installed by Windows NT. Can will Not be connected with him through dial-up from Linux. Scenario waits login: and password:, but from there does not come no lines. Links Linux-Linux, Linux-Free BSD, worked without any problems. Who known what is wrong? CCL: Invalid command (c).
It sounds like you should try talking to your ISP. If they won't co-operate or help, switch to another one.
If there aren't any others in your area, find some friends and form your own -- either a co-op or a commercial. Welcome to the free market!
They are probably using some proprietary MS RAS (remote access service) or they've done something weird with their terminal servers or PPP software --- though the fact that it connect and prompts for a login and password doesn't sound like a MS NT RAS or PPTP sort of symptom --- those are text and MS prefers to use proprietary binary in their protocols and document formats.
In any event I don't have nearly enough information to help.