IBM Advanced Peer-to-Peer Networking
（重定向自APPN）
Advanced Peer-to-Peer Networking (APPN) is an extension to the Systems Network Architecture (SNA).
It includes features such as these:
APPN was meant to complement IBM's Systems Network Architecture, a legacy from the mainframe era. It was designed as a simplification, but it turned out to be utterly complex, in particular in migration situations. APPN was originally meant to be a "DECNET killer", but DEC actually died before APPN was completed. APPN has been largely superseded by TCP/IP (Internet).