An independent LU can communicate directly with a peer system and does not need the support of a host computer. Independent APPC LUs, as used in AS/400 APPN networks, provide the ability to run multiple, concurrent, parallel sessions between a local and remote LU pair.
When configuring independent APPC LUs, you should note that when Host Integration Server 2006 is used to communicate with a transaction program (TP) on a mainframe over an independent APPC LU, the host system must be running VTAM version 3, release 2 (V3R2) or later. The version of Network Control Program (NCP) required on the mainframe depends on the type of front-end processor (FEP) used. For 3725 systems, NCP V4R3 or later is required. For 3745 systems, NCP V5R2 or later is required.
Other Resources
APPC Deployment Strategies