# Using the function reference

This section provides an alphabetical reference to the NMS ISDN Management service functions. A prototype of each function is shown with the function description and details of all arguments and return values. A typical function description includes:

Prototype | The prototype is shown followed by a listing of the function's arguments. Data types include: WORD (16 bit unsigned) DWORD (32-bit unsigned) INT16 (16-bit signed) INT32 (32-bit signed) BYTE (8-bit unsigned) If a function argument is a data structure, the complete data structure is shown. Refer to IMGT data structures for a description of all data structures and parameters.
Return values | The return value for a function is either SUCCESS or an error code. For asynchronous functions, a return value of SUCCESS indicates the function was initiated; subsequent events indicate the status of the operation. Refer to NMS ISDN Management service errors for a list of all errors returned by NMS ISDN Management API functions.
Events | If events are listed, the function is asynchronous and is complete when the DONE event is returned. If there are no events listed, the function is synchronous. Additional information such as reason codes and return values may be provided in the value field of the event. Refer to NMS ISDN Management service events for details about NMS ISDN Management API events and reason codes.
Example | Example functions that start with Demo are samples taken from demonstration function libraries shipped with the product. Example functions that start with my are excerpts taken from sample application programs shipped with the product. The notation /* ... */ indicates additional code that is not shown.