User-written APPC applications

APPN performs many functions in a communications environment. Therefore, it is important to consider time-out parameters in APPC programs which use ICF. In particular, it may be important to increase the WAITFILE parameter for these applications so that they do not time-out while waiting for APPN functions to be performed.

APPN function is not apparent to APPC programs. APPN takes advantage of the following routing functions:

• Non-adjacent nodes appear adjacent and so APPC programs may communicate directly to programs in non-adjacent nodes (without any APPC programs on the intermediate nodes).
• Performance is improved for APPC programs with session endpoints that are not physically adjacent in the network.
• APPC programs may communicate directly to programs in nodes in an adjacent APPN network through network nodes.