# nccDisconnectCall and specifying extended information

With certain NMS CAS protocols, when an application attempts to disconnect a call with nccDisconnectCall, extended information can be sent with the call disconnect request. This information is included in the CAS_DISCONNECT_EXT structure which is a component of the NCC_ADI_CAS_PARMS structure:

typedef struct
{
DWORD size; /* size of this structure */
WORD cause; /* disconnect cause */
WORD pad;
} CAS_DISCONNECT_EXT;

In the function call, the NCC_ADI_CAS_PARMS structure is referenced using the void *protcallparms argument.

The CAS_DISCONNECT_EXT structure contains the following fields:

Field | Protocols that use the field | Description
--- | --- | ---
size | All | Size of this structure.
cause | WNK, STA | Disconnect cause. Determines the call progress tone sent to an off-hook, disconnected party.