An LU 6.2 application can specify itself on the LUNAME parameter of a CNOS request. This allows transaction programs on the application to allocate LU=OWN conversations. If VTAM® determines that the target LU is the same as the source LU for the CNOS request, VTAM accepts the request and manages the CNOS negotiation as follows:

1. Builds source-side LU-mode table entries as needed.

   VTAM determines whether an LU-mode table entry exists for the logon mode being negotiated between the LU-LU pair. If one does not exist, VTAM builds and initializes the entry using default defined negotiation limits.

2. Builds a CNOS session limits control block, if needed.

   If the application program did not specify a CNOS session limits control block when it issued the APPCCMD CONTROL=OPRCNTL, QUALIFY=CNOS macroinstruction, VTAM builds one for the application program, using the defined negotiation limits in the LU-mode table. This CNOS session limits control block represents the proposed session limits for the source side.

3. Starts SNASVCMG conversation.

   The source-side VTAM starts a conversation with the target-side VTAM using the SNASVCMG mode.

   Note: The application program does not have to negotiate CNOS session limits for the SNASVCMG mode before requesting a CNOS negotiation for another user logon mode. VTAM defaults the SNASVCMG mode limits to (2,1,1) automatically when needed.
4. Bypasses target side CNOS processing.

   Because the source side LU and the target side LU are the same, the proposed session limits are not sent to the target side. A separate target side LU-mode entry is not built. One LU-mode entry suffices for both sides.

5. Adjusts proposed session limits.
   The proposed session limits are adjusted as follows:

   • The requested SESSLIM value is doubled. This is because each time a session is used, internal session representations are used two at a time.
   • The number of contention winner sessions is set to the requested SESSLIM value.
   • The number of contention loser sessions is set to the requested SESSLIM value.

   For example, if SESSLIM=10, then VTAM sets the session limits to (20,10,10).

6. Updates the LU-mode table.

   If the adjusted session limits are deemed acceptable, then VTAM updates the session limits in the LU-mode table to reflect the adjusted values.

7. Does not schedule the ATTN exit.

   Unlike normal CNOS processing, when an LU requests a session with itself, the ATTN(CNOS) exit is not scheduled on the target side.

8. Initiates session activation or deactivation as needed.

   When the session limit negotiation is successful, VTAM initiates session activation or deactivation as needed. If AUTOSES is set on, VTAM tries to match it within the constraints of the session limits and to satisfy all session activation requests that are waiting.

9. Completes the CNOS macroinstruction.

   VTAM sets return codes and posts them to the source application program. If the application program specified a CNOS session limits control block on the APPCCMD CONTROL=OPRCNTL, QUALIFY=CNOS macroinstruction, the negotiated session limits are copied back to the CNOS session limits control block when the macroinstruction completes.