Advanced Peer-to-Peer Networking. Enhancement to the original IBM SNA architecture. APPN handles session establishment between peer nodes, dynamic transparent route calculation, and traffic prioritization for APPC traffic. Compare with APPN+.

Distributed Data Management. Software in an IBM SNA environment that provides peer-to-peer communication and file sharing. One of three SNA transaction services.

Term used to describe distributed computing (processing) network systems in which transaction responsibilities are divided into two parts: client (front end) and server (back end). Both terms (client and server) can be applied to software programs or actual computing devices. Also called distributed computing (processing). Compare with peer-to-peer computing.

The major advantages of the client/server networking arrangement include centralized administration and data and resource security.

Asynchronous Balanced Mode. An HDLC (and derivative protocol) communication mode supporting peer-oriented, point to- point communications between two stations, where either station can initiate transmission.

A network in which data sharing occurs directly between computers, with no central server to control communications and other services.