# Receiving overlapped digits

Some protocols support overlapped receiving of digits: the application receives an event as each digit comes in. The application can examine each digit to determine what to do with the call earlier in the call setup process.

The NCC.START.overlappedreceiving parameter in the NCC_START_PARMS structure determines whether the protocol accepts digits in overlapped receiving mode or not. This parameter is referenced within the initial invocation of nccStartProtocol.

If the protocol accepts digits in this mode, the application can receive NCCEVN_RECEIVED_DIGIT while the protocol is in the seizure state. The event value field contains a digit received from the network. At this point, the protocol enters the receiving digits call state. It remains in this state until all digits are received. As each digit is received, a new NCCEVN_RECEIVED_DIGIT is generated with the digit. Receipt of NCCEVN_INCOMING_CALL indicates that all digits were received, and the protocol has entered the incoming call state. The complete set of digits is then available in the NCC_CALL_STATUS structure.

The application can use nccAcceptCall, nccAnswerCall, or nccRejectCall to accept, answer, or reject the call at any time while receiving digits.