Locating resources in a subarea network

In a subarea network, when VTAM® receives a session initiation or directory search request for a resource that is not located in that VTAM domain, it attempts to locate the resource by sending the request to its adjacent SSCPs.

If the resource is statically defined as a CDRSC (or matches an active model CDRSC) and has the CDRM operand defined, VTAM routes the request to the SSCP specified in the CDRM operand. VTAM uses an adjacent SSCP table if:

The CDRM operand is not defined
The resource is not found at the CDRM specified
VTAM has no SSCP-SSCP session with the specified CDRM
The CDRSC is dynamically defined

The adjacent SSCP table can be statically defined or, if the start option DYNASSCP is defined as YES (which is the default), it can be dynamic. VTAM searches each SSCP in the table for the resource until the resource is found or the table is exhausted. See Adjacent SSCPs for additional information about using adjacent SSCP tables.

For independent LUs located on or through adjacent LEN nodes, VTAM uses these definitions to determine connectivity to the resource when establishing a session with the independent LU.