Process data arriving at the Modem.

[babar]

Data from web servers arrives at modem, Modem handles it over to some other program for the Protocol Stack and finally submit to the reuqesting applications.<br>I needed to keep a check on all the data coming through modem looking for a particular signal.That should be done before data gets distributed between applications and even before it is passed through the protocol stack.<br>&nbsp;&nbsp;&nbsp;&nbsp;In other words, &quot;How to take data for some searching through it as soon as it is available from the modem, after search handle it over to the operating system for further routine processing&quot;.<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;How could I do this, or Where should I start from?<br>