LU 6.2 enables a VTAM® application program to communicate with nonhost application programs on an advanced program-to-program communication (APPC) level. Without LU 6.2, the nonhost program usually must emulate a terminal when communicating with a VTAM application program, using protocols that are not well-suited for application programs and that diminish the nonhost application program ability to handle errors and to initiate and end communications.

LU 6.2 protocols are designed to optimize use of sessions and improve the efficiency of data transfer through the network. LU 6.2 can also simplify the program logic needed to establish communications with other application programs and to send and receive data. Though VTAM support simplifies the task of writing application programs that use LU 6.2, be aware that enabling VTAM support requires some LU 6.2 functions to be implemented by an application program.

You can write or modify host application programs to use LU 6.2 protocols throughout the network.