Although the VTAM® program implements a large portion of the LU 6.2 function, the application program must implement some of it. The application program also can implement some optional LU 6.2 functions. This chapter describes the following items:

• Functions that VTAM implements
• Functions that the application program implements (pass-through verbs and mapped conversation verbs)
• Optional LU 6.2 functions

Refer to SNA Transaction Programmer's Reference Manual for LU Type 6.2 for more information on the architecture.