(also TNC)
A terminal node controller (TNC) is a device that acts as an interface between a computer and a radio to facilitate data communication over amateur radio networks. TNCs are primarily used for packet radio, a communication protocol that enables transmission of digital data packets via radio frequencies. They consist of a modem, a processor, and firmware that encodes and decodes data packets according to the AX.25 protocol, ensuring reliable data exchange between radio devices.
See also: broadcast address, class C IP address, network security protocols
While TNCs have dedicated hardware and firmware for handling digital communication, sound card modems utilize a computer’s sound card and software to perform similar functions. Sound card modems are more affordable and versatile but may be less reliable and perform more slowly than dedicated TNCs.