Example network-specific lists

The rest of the adjacent SSCP table is used when VTAM® sets up sessions with CDRSCs whose owning CDRM and network are known. For example, if GWSSCP21 has the following definition statement coded in its CDRSC major node:

        NETWORK  NETID=NETWORK3
TSO02   CDRSC    CDRM=GWSSCP32

Because the CDRM is coded on the CDRSC definition statement, VTAM assumes that this CDRM is the true owner of the resource. Because the NETWORK definition statement is coded, VTAM uses the coded CDRM and the network-specific SSCP table to try to locate the CDRSC.

VTAM first builds an adjacent SSCP table for the CDRSC. The CDRM is defined as SSCP1, so GWSSCP32 is the first entry in the list. The rest of the list consists of the SSCPs that are adjacent to GWSSCP32, as defined in the default portion of the sample table:

GWSSCP32 CDRM
GWSSCP31 ADJCDRM

If the session setup fails through GWSSCP32, VTAM routes the request through GWSSCP31.

If no network had been coded for TSO02, VTAM would have used the default SSCP list (GWSSCP11, GWSSCP31, GWSSCP32, GWSSCP41, GWSSCP42). This could result in some session setup requests being routed outside the network through the gateway SSCPs. The adjacent SSCP table can thus prevent time and resources from being used in a search that might be unnecessary. The session management SSCP selection function can also be used to alter the SSCP list.

For VTAM Version 3 Release 2 and later releases, an ADJSSCP table defined with a NETWORK definition statement for the host network is used only when the destination resource is known to reside in the host network. If a destination resource is known to reside in NETWORK2, the list of ADJSSCPs used for a session request is:

GWSSCP22
GWSSCP23

Before VTAM Version 3 Release 2, an ADJSSCP table defined with a NETWORK definition statement for the host network is treated as a default table.