Adjacent SSCP table
The adjacent SSCP table is used only by nodes with subarea capability. Thus, nodes which have APPN capability but not subarea capability do not use adjacent SSCP tables.
The adjacent SSCP table contains lists of adjacent SSCPs that can be in session with a host VTAM® or used to establish sessions with SSCPs in other networks. VTAM searches other SSCPs when it receives a session request for a resource that is not in its domain. First, it sends a session initiation request to the SSCP specified in the CDRM operand of that resource's CDRSC statement. If a CDRM is not coded, and you have a default SSCP list, VTAM sends the session setup request for the 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. You can also allow VTAM to dynamically define an adjacent SSCP table by coding the start option DYNASSCP=YES or letting it default.
To improve SSCP search performance, you can use the adjacent SSCP selection function of the session management exit routine to shorten or reorder the list of adjacent SSCPs to which an LU-LU session request is directed.
For more information about adjacent SSCP tables, see the z/OS Communications Server: SNA Network Implementation Guide and the z/OS Communications Server: SNA Resource Definition Reference.
The adjacent SSCP tables for the subarea-capable nodes in the network depicted by Figure 1 follow.