I am little new to Linux and Amateur Radio however I am interested in the subject area. However despite all the HOWTO's and documentation however I am still unsure as to what the AX.25 protocol actual does. I have bought a second hand BayCom Modem and understand that the bits written by Thomas Sailer make Linux one of the few OS's to support it. Am I right in thinking that the AX.25 is a basic layer that any of the applications can use? Or do most of them communicate with the TNC itself. I would apreciate anyone who tries to explain this to me. Thanks a lot Tom Edwards