Basic APPN Concepts

Advanced Peer-to-Peer Networking (APPN) is a network architecture that supports distributed network control. It makes networks easy to configure and use, provides centralized network management, and supports flexible connectivity.

An APPN network is composed of type 2.1 nodes. Each node in the network is connected by a link to at least one other node in the APPN network. CP-CP sessions are established over each of these links to adjacent nodes (nodes in the same network that can establish direct links without going through a third node). All of the nodes in an APPN network share a common network name.

APPN nodes can include processors of various sizes, such as the Application System/400 (AS/400), PCs running Communications Server for Data Center Deployment running Linux, systems using Virtual Terminal Access Method (VTAM®), and AIX servers running CS/AIX.

APPN provides the following functions:

Support for APPN network nodes and end nodes as well as non-APPN peer nodes (see APPN node types)
APPN control point functions (see APPN control point)
Directory services to support finding specific logical units (see Locating resources)
Topology and routing services to support session establishment using intermediate session routing (ISR), automatic network routing (ANR), or connection networks (CNs) (see Session Routing and APPN connection networks)

Note: An APPN node can also be connected to a subarea network, serving as both an APPN node in a peer network and a peripheral node in a subarea network.