The CPCP start option specifies whether an APPN node supports CP-CP sessions with an adjacent node. The CPCP start option is valid only for nodes at which the NODETYPE start option is specified. APPN nodes use CP-CP sessions to communicate topology, routing, directory, and session information to adjacent control points. If you use the default, CP-CP sessions are supported on all APPN leased links. Because CP-CP sessions carry network control information, they should be active as long as the node is active. Using the default allows you to control whether your APPN switched links support CP-CP sessions on a link-by-link basis by defining the CPCP operand.

You can use the CPCP start option to specify support for CP-CP sessions on leased links only, on switched links only, on both leased and switched, or on neither leased nor switched.

The CPCP operand can be coded on the PU definition statement for the local SNA, model, NCP, and switched major nodes.