Defining the location of cross-domain resource managers by coding adjacent SSCP tables

In a multiple-domain network, session setup involves VTAM® locating resources (session partners) in the network. Resources are located by routing a session initiation request to VTAMs in other domains. You can define a list of cross-domain resource managers (CDRMs) to which a session setup request can be routed. The list of CDRMs that you code for the search (referred to as adjacent SSCPs) can be supplemented dynamically by your VTAM domain. The search order, and the number of VTAMs to which the session request is routed, can affect session setup time. For more information, see Adjacent SSCPs.

VTAM provides two start options, SSCPDYN and SSCPORD, that control how VTAM processes adjacent SSCP tables. SSCPORD can be specified as a start option or coded on individual ADJSSCP table definitions (or both).

SSCPDYN start option: SSCPDYN determines whether VTAM should add entries dynamically to the adjacent SSCP table (that is, supplement the list of adjacent SSCPs that you have coded with other SSCPs that it discovers dynamically). The addition of these entries to the list can increase the time needed to search for a cross-domain resource.
If you code SSCPDYN=NO, you might have to define additional adjacent SSCP tables. When an application program passes a session (issues a CLSDST PASS macro instruction) during session setup, VTAM does not build an adjacent SSCP table in the application program network. When SSCPDYN=YES is specified in the application program network, VTAM builds an entry in the table automatically.
SSCPORD start option: SSCPORD determines the order in which VTAM processes the entries in the table to route session requests to adjacent SSCPs. SSCPORD can be specified as a start option, modified using MODIFY VTAMOPTS, or coded separately for each ADJSSCP table (or all three). If SSCPORD is not coded for a given ADJSSCP table, the current value of the SSCPORD start option value is used each time that ADJSSCP table is selected for use. SSCPORD indicates whether VTAM is to process the list in the order in which it is defined (DEFINED) or whether it is to route the session request to the last successful entry (PRIORITY). VTAM remembers successful and unsuccessful adjacent SSCP entries for routing session initiation requests. If you specify SSCPORD=PRIORITY, VTAM always uses the last successful adjacent SSCP entry to route the session setup request.
One exception to order of search, regardless of the SSCPORD value, is that VTAM always routes the session-initiation request directly to the VTAM that owns the resource if it has an SSCP-SSCP session with that owner.