views:

95

answers:

1

Hi. is it possible to call Computer A with Computer B in Same Country via theirs dial up modems? i mean use computer as telephone (with Dial Up modem) i no need transferring voice just : 1) Computer A Dialing Computer B (with the Phone number) 2) Computer B is see that computer A is calling. 3) Computer B Answer.

please putting sample code or link for more information. if there is any library exist that made my work easier introduce to me. i don't want to involving with AT Commands. does this library help me? Have I Use TAPI? thanks.

+6  A: 

Yes. As long as both computers have compatible modems. You'll need terminal software for both computers (probably hyperterm for WinXP, but it's been a while, so I can't say for sure). Basically, you'll need to have one computer call the other computer sending a string like "ATDxxxxxxx" where xxxxxxx is the phone number of the receiving computer. When the line starts ringing on the receiver, type "ATA" on the receiving computer to tell the modem to answer. After the handshake you should get a "CONNECT" message. Mind you, all this is subject to individual quirks of the modems and my memory, as it's been at least 8 years since I've done any work with dial up at all. But it should give you the basic idea.

Jim Nutt
IIRC it's ATDT<phone number> to take the phone off-hook and dial. The part that tends to vary on the receiving end is the string that is send over the COM port when the phone is ringing. My USRobotics modem back in the day said "RINGING".
Dave
thanks. your answer was Helpful. is there any library exist to not involving me with AT Commands ?
shaahin
Probably, but there really aren't that many of them that you need to deal with and it's just a matter of sending them as strings to the modem. Here's a list of them from Microsoft that seems fairly complete: http://support.microsoft.com/kb/164660. They are all prefixed with "AT". If you're already connected, you can usually put the modem back into command mode by typing "+++" and waiting a couple of seconds.
Jim Nutt