LUs, Local LUs, and Partner LUs
A logical unit (LU) manages the exchange of data between application programs. Every LUA application program gains access to an SNA network through an LU, which acts as an intermediary between the LUA application program and the SNA network.
In LUA, there is a one-to-many relationship between LUA application program processes and LUs. One LUA application program process can own multiple LUs simultaneously, but a given LU can be owned by only one LUA application program process simultaneously. Before a second application program process can use an LU, the first application program must release the LU.
An LUA application program issues LUA verbs to its local LU. These
verbs cause commands and data to flow across the network to the partner LU.
Note:
You need to define your local LU only once for each machine, as
described in Quick Beginnings.