# WNK and NCC service call control

When applications receive inbound calls using NCC service call control with the WNK TCP, they can process digits in one of the following ways:

Method of processing digits | Description
Receiving digits all at once | With wink start-derived TCPs, after NCCEVN_INCOMING_CALL is received, the calledaddr field in the NCC_CALL_STATUS structure usually contains all received digits. The callingaddr, usercategory and tollcategory fields are usually NULL. The parameter NCC.X.ADI_WNK.numdigits determines the number of digits the TCP should expect from the calling party (including ANI digits and the * (asterisk), when expecting ANI). The default is 3. Note: With the WNK0 TCP digital two-way wink start, if the parameter NCC.X.ADI_WNK.anididtone is set correctly, any ANI digits in the digit string are presented to the application in the callingaddr field.
Receiving digits one at a time | To receive digits one at a time, make sure the Ncc.Start.OverlappedReceiving parameter is set. In general, digits are presented in the order in which they arrive. If ANI are present, the DTMF tones * (asterisk) and # (number sign) are also present in the digits received by the TCP. Only the * (asterisk) (separator between ANI and DID) is passed to the application though, not the # (number sign), that signals the end of the digit string (ST tone). When receiving digits one at a time, the application must know the order of the fields in the digit string (ANI or DID first).