This is the protocol used for computer communication over amateur
radio. It is either used by itself for point-to-point links, or to
carry other protocols such as tcp/ip. To use it, you need a device
that connects your Linux box to your amateur radio. You can either
use a low speed TNC (a Terminal Node Controller acts as a kind of
modem connecting your computer's serial port to your radio's
microphone input and speaker output) supporting the KISS protocol or
one of the various SCC cards that are supported by the generic Z8530
or the DMA SCC driver. Another option are the Baycom modem serial
and parallel port hacks or the sound card modem (supported by their
own drivers). If you say Y here, you also have to say Y to one of
those drivers.

Information about where to get supporting software for Linux amateur
radio as well as information about how to configure an AX.25 port is
contained in the AX25-HOWTO, available from
<https://www.tldp.org/docs.html#howto>. You might also want to
check out the file <file:Documentation/networking/ax25.rst> in the
kernel source. More information about digital amateur radio in
general is on the WWW at
<https://www.tapr.org/>.

To compile this driver as a module, choose M here: the
module will be called ax25.

source code:

net/ax25/