Routing with adjacent SSCP tables

If you have defined an SSCP list, VTAM® sends the session setup request for an undefined destination logical unit to each SSCP in the list until either the owning SSCP is found or the end of the list is reached. If VTAM does not have an SSCP-SSCP session with an adjacent SSCP in the list, the SSCP is ignored. If a session setup request is routed to an SSCP that does not own the destination logical unit, the request is rejected.

For reliability during session setup, VTAM does the following actions:

Associates the adjacent SSCP with a cross-domain resource whenever it receives a session initiation request from an SSCP that is not already in the table
When looking for an SSCP with which to initiate a session, scans the adjacent SSCP table in priority order, giving preference to:
- SSCPs for which the most recent session initiation attempt succeeded
- SSCPs for which no session initiation attempts have been made

VTAM bypasses any SSCP in the list with which it does not have an SSCP-SSCP session. If the owning SSCP is not found, the session request is rejected, and the dynamic CDRSC is deleted immediately. VTAM does not wait for the time value specified in the CDRSCTI start option.