(Page 7 of 7 in this chapter)

TxDIOpen

Applications must call TxDIOpen before calling any of the other Ds0 Over IP routines. This function will allocate the previously defined virtual ports for use by the API and open a communications channel to the TX board that is used for all connect and disconnect requests.
Note: If the application being written is designed as a multi-threaded application, it is critical that all TxDIXxxxx functions be called from the same thread. The communications channel opened to the TX board has a read posted through the Host Operating System to the low level driver at all times. This read is posted for the thread that has done the open, if other threads attempt to make connect and disconnect requests, the responses to these requests will completed to the incorrect thread, and a new read will be posted by the thread that does not own the opened channel. This will result in undesirable behavior by the application.