To determine the current line status, call TxT1E1CarrierStatus at any time. TxT1E1CarrierStatus returns the following information:
Current state of the line (carrier and frame synchronization status)
Whether or not an alarm is currently present
Current configuration parameters (such as framing mode and line coding)
Current performance statistics
Optionally, the application can request to be notified through an unsolicited message any time the synchronization state of the line changes (carrier or synchronization established or lost) or any time an alarm condition is detected or cleared.
Unsolicited status messages are delivered out-of-band. They come to the application through a separate interface to the TX device driver rather than directly from the library. The application must first call TxT1E1SuperviseCarrier to register the events for which it wants to be notified. Refer to Handling unsolicited T1/E1 notifications for more information.