RXTX to dial a telephone number in digiteal ine
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I made an applet , to dial a telephone number using RXTX . The applet is working fine with analog modem(V.92) and an anlog telephone line.
Now, I am interested in using the same applet for dialing a telephone number with a digital line.
I , undertand that analog modem ain't compatiable with digital line, still tried to connect my analog modem(V.92) with the digital line and ran my applet. Unfortunately I dont see any thing happening in the modem , which I guess, means there is no call getting placed.
Can someone suggest how to get this done with digital telphone lines.
should I buy a digital modem ? 
also , do I need to change anything in code as well ? e.g baud rate etc.

Any kind of help would be highly appreciated ?