The session accounting exit routine allows you to collect statistics on the number of times that sessions start and end so that users can be charged accordingly.

Whenever possible, you should use a session management exit routine rather than an accounting exit routine to gather accounting information, because the session management routine allows you to combine session-related functions into one exit routine. The session management exit routine also fully supports cross-network and takeover processing. For example, information passed to the accounting exit routine for cross-network sessions might be misunderstood because LU names are not necessarily unique. The session management exit routine's accounting function avoids this problem because additional LU information is provided to the exit in the PLU and the SLU resource information control vectors. (See Session management exit routine for more information about its capabilities.)

The session accounting exit routine is scheduled only in SSCPs that are in the same domain as one of the LUs. If both the accounting and session management exit routines are provided within the LU's domain, VTAM® schedules both exits.

IBM® does not supply a skeleton session accounting exit routine. Write a session accounting exit routine if you want this function. If you do not write this routine, all session accounting information intended for the routine is discarded.

The following topics contain information you need to write a session accounting exit routine.