IBM Advanced Peer-to-Peer Networking
Advanced Peer-to-Peer Networking (APPN) is an extension to Systems Network Architecture.
It includes features such as:
- distributed network control
- dynamic exchange of network topology information to foster ease of connection, reconfiguration, and route selection
- dynamic definition of network resources
- automated resource registration and directory lookup.
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 passed a way before APPN was completed. Today, of course, APPN is completely superseded by TCP/IP (Internet). Note that APPN has nothing to do with controversial peer-to-peer file sharing software such as KaZaa or Napster. The designation peer-to-peer in the case of APPN refers to its independence from a central point of control, unthinkable in today's networks but common in the mainframe era.