| 摘要 |
A cleaning system retrieves a telephone number from a telephone number list to regard as a called party number and sends a SETUP message to the network, in which an unrestricted digital information is designated as a bearer capability. In case that an ALERTING or CONNECT message is sent back from the network, the system sends a DISCONNECT message to the network immediately to perform a clear sequence and determines the telephone number effective. In case that a DISCONNECT message is sent back from the network as a result that a call has not been accepted, the system also performs a clear sequence immediately and determines if the telephone number should be treated as an effective number or a null number according to the cause content sent from the network. |
