Systems Network Architecture Considerations (SNA) › Allocating a Session

Allocating a Session

ALLOCATE LU_NAME
         MODE_NAME
         SYNC_LEVEL
         TPN
         SECURITY (PROGRAM (USER_ID, PASSWORD))
         TYPE (CONVERSATION)
         RETURN_CONTROL (WHEN_SESSION_ALLOCATED)
         RETURN_CONTROL (IMMEDIATE)
         RESOURCE
         RETURN_CODE

The #TREQ ALLOC statement allows you to allocate a conversation with another logical unit. In most cases, CA IDMS/DC selects a session for you from sessions defined at system generation. The system bases its selection on session attributes you have established in the UIOCB. You should initialize the following UIOCB fields before you allocate a session:

• The name of the LU (UIORLU) with which your program will be communicating.
• In some special cases your program may need to specify the name of a MODEENT table (UIOMODE), requesting a specific session for the conversation. Most programs do not have to specify UIOMODE.

  Note: For more information about session modes, see the System Generation Guide.

• The maximum sync level (UIOSYNC) your task will need (LU6.2 only).

Instead of coding these parameters and letting CA IDMS/DC select a session for you, you can use the LTERMID parameter of the #TREQ ALLOC statement to allocate a specific session, identified by the logical terminal name of the other LU. For example:

#TREQ ALLOC,LTERMID=LTERMIDA

When LTERMID is specified, the UIORLU and UIOMODE fields in the UIOCB are ignored.