Sample session management exit routine

The session management exit routine controls various functions associated with VTAM® logical unit session processing. These functions include:

Initial and secondary session authorization
Initial and final session accounting
Gateway path selection
XRF session switch
Adjacent SSCP selection
Alias selection
ALS selection
Exit replacement
Exit replaced

For a complete description of the exit functions, see Session management exit routine. If you write a session management exit routine, you should use the interface information described in that section.

The sample session management exit routine in this topic is only prototype code that can be included in a more complete and comprehensive session management exit routine. The sample code illustrates how the initial session management exit routine environment is established, the type of information that is available in each parameter list for the specific sample environment, and some techniques used to examine the various parameter lists. The sample session management exit routine is written specifically for the SNA network environment illustrated in Figure 1. The sample uses only the following session management exit routine functions:

Begin
Secondary session authorization
Gateway path selection
Alias selection
End

A portion of a final accounting function is also included. However, the code is related specifically to the alias function. The initial and final accounting functions are normally used to record session connection time.

Note: The examples in this topic are intended as an educational tool. They show how various functions in a session management exit routine can be used to control VTAM functions. The examples shown are coded to a specific network environment and are not compatible with any other installation configuration or processing requirements.

Figure 1. Network environment for sample session management exit routine

Shows the SNA network for which the sample session management exit routine is written