what is appn do
Advanced Peer-To-Peer Networking (APPN) Advanced Peer-To-Peer Networking (APPN) Definition - What does Advanced Peer-To-Peer Networking (APPN) mean? Advanced Peer-to-Peer Networking (APPN) is part of an IBM Systems Network Architecture (SNA). It involves protocols for allowing computers to communicate between themselves, rather than being dominated by a central server or other hardware piece.