Ways to Increase the Number of AS/400 LU6.2 Sessions (126395)

This article was previously published under Q126395

By default there are 64 sessions per LU-LU pairing in SNA Server, as defined by the QPCSUPP mode. To increase the number of sessions, perform one or both of the following:

1. Create more Local APPC LUs in SNA Server Admin/Manager. Each LU/LU partnering over the QPCSUPP mode supports up to 64 sessions by default.
2. Increase the session limits in QPCSUPP mode on the AS/400 and in the SNA Server Admin/Manager. The maximum for session limits is 512. This number is imposed by OS/400 (the AS/400 operating system).
   
   To increase these session limits in SNA Server 2.x:
   1. Choose Remote LU.
   2. Choose Partners.
   3. Choose Mode.
   4. On the QPCSUPP mode, change the Parallel Session Limit to 512 (or the desired number) and change the Minimum Contention Winner Limit to half this value.
   To increase the session limits in SNA Server 3.0 and later:
   1. Select the APPC Modes folder in SNA Server Manager.
   2. Right-click QPCSUPP in the right-hand pane and click Properties on the context menu.
   3. Select the Limits tab in the QPCSUPP Properties dialog box.
   4. Change the Parallel Session Limit to 512 (or the desired number) and change the Minimum Contention Winner limit to half this value.
   NOTE: After you change and save the SNA Server configuration, stop and restart the SNA Server service.

To change the session limits on the AS/400, use the CHGMODD(QPCSUPP) command.

• Maximum sessions (MAXSSN) must match the parallel session limit.
• Maximum conversations (MAXCNV) must match the parallel session limit.
• Locally controlled sessions (LCLCTLSSN) must match the partner minimum contention winner limit.

NOTE: Mode definition changes on the AS/400 may not be dynamic. You will need to vary off the controller for SNA Server and then vary it back on for the mode changes to take affect.

To verify the mode settings that are currently negotiated, use the following AS400 commands at the AS400 command line: and press Enter. Then choose the device (next entry down from the controller), and place a 9 next to the device and press Enter to display the mode status. Finally place a 5 next to the QPCSUPP mode and press Enter to display the currently negotiated mode status.