An application must issue a rapi_sender() call if it intends to send a flow of data for which receivers can make reservations. This call defines, redefines, or deletes the parameters of that flow. A rapi_sender() call can be issued more than once for the same API session; the most recent one takes precedence.

After a successful rapi_sender() call has been made, the application can receive upcalls of type RAPI_RESV_EVENT or RAPI_PATH_ERROR.