If your installation has VTAM® Version 4 Release 4 installed, you can enable APPC/MVS LUs to support of VTAM network-qualified LU names, which reduces the effort of changing the distributed processing environment in an installation that includes several interconnected networks. Previously, if your company merged with another, and added that company's existing network to your installation, system programmers or administrators had to rename any LU that did not have a unique network LU name (the 8-byte local LU name) within the larger installation. Renaming an LU requires changes to several sources of configuration data on several systems, which complicates the tasks required only to define an LU on other systems.

With APPC/MVS support of network-qualified names, renaming LUs is no longer necessary when your installation adds networks containing z/OS systems. To use this support, you specify the NQN parameter on the LUADD statement to enable that APPC/MVS LU to use the entire network-qualified name for partner LUs. (Without this support, APPC/MVS uses only the network-LU-name portion of an LU name on outbound Allocate calls. In this case, the results of Allocate calls using a network-qualified partner LU name are not guaranteed to be established with the correct partner LU.)

Once your installation changes LUADD statements to make LUs capable of using the entire LU name, the network ID makes the LU name unique. Then, your installation's TPs can use network-qualified partner LU names on Allocate calls, with guaranteed results.