Abbreviated APPN. IBM's SNA (Systems Network Architecture) protocol, based on APPC (Advanced Program-to-Program Communications). APPN allows nodes on the network to interact without a mainframe host computer and implements dynamic network directories and dynamic routing in an SNA network.
APPN can run over a variety of network media, including Ethernet, token ring, FDDI, ISDN, X.25, SDLC, and higher-speed links such as B-ISDN or ATM.
See also Asynchronous Transfer Mode; Customer Information Control System; Systems Network Architecture.