digipeater for APRS

 Aprsdigi is a specialized Amateur Packet Radio (AX.25) UI-frame digipeater for
 the Automatic Position Reporting Systems, APRS(tm). It uses the Linux kernel
 AX.25 network stack as well as the SOCK_PACKET facility to listen for packets
 on one or more radio interfaces (ports) and repeat those packets -- with
 several possible modifications -- on the same or other interfaces. Aprsdigi can
 also use the Internet to tunnel connections among other APRS digipeaters and
 nodes using IPv4 or IPv6 UDP unicast or multicast.