Before a SPP for a communication event can receive communication events, its service group name and service name must be specified in the XATMI communication service definition. Communication events that can be received by the SPP vary depending on the operand to which the service group name and service name are assigned as follows:

xat_aso_con_event_svcname operand:

Communication events reporting association establishment

xat_aso_discon_event_svcname operand:

Communication events reporting normal association release

xat_aso_failure_event_svcname operand:

Communication events reporting abnormal association release

If you assign the same service group name and service name to multiple operands, the SPP for a communication event can receive multiple types of communication events.

Assign betran to the server_type operand in the user service definition for the SPP for a communication event.

The SPP for a communication event can invoke a function to establish an association. The function dc_xat_connect() [CBLDCXAT('CONNECT')] is used for this purpose. When this function returns, the SPP for a communication event can receive information about the fact that an association has been normally established.

The function dc_xat_connect() can establish an association only if the local system is the initiating side. In addition, since the function return is not synchronized with the association establishment, the service function that has invoked the function dc_xat_connect() cannot receive the communication event that reports the association establishment.

Association establishment is reported in the following cases:

• Association establishment at the time of OpenTP1 system start
• Association establishment caused by nettactcn command execution
• Association establishment requested by SPP for a communication event
• Association establishment initiated by remote system

Association release is reported in the following cases:

• Forced association release caused by nettactcn command execution
• Association release caused by error in lower layer
• Association release caused by fault in TP1/NET/OSI-TP-Extended
• Association release caused by XATMI communication service failure
• Failure in association release
• Normal association release initiated by remote system
• Forced association release initiated by remote system