Local TPs are created by issuing the TP_STARTED verb to SNA Server. The TP_STARTED verb has been modified by adding the new VCB member syncpoint_rqd to allow a TP to specify that it requires Sync Point services.
By setting syncpoint_rqd to AP_YES, a TP indicates that it requires Sync Point services from SNA Server. A value of AP_NO (the default) indicates that Sync Point services are not required.
Since this member cannot be incorporated within the existing TP_STARTED VCB, the TP must use a larger VCB structure. To indicate that the VCB is longer than usual, the opext member of the VCB must be combined using OR with the value AP_EXTD_VCB before calling APPC.
If the TP is started on a server running SNA Server software earlier than version 3.0 with the opext member of the VCB set for Sync Point support, the TP_STARTED verb will fail with a primary return code of AP_INVALID_OPCODE.
Conversations started by TPs requiring Sync Point support will be routed only by the SNA Server software running on the same machine. They will not be routed to other LAN-attached servers.