The linePark function parks the specified call according to the specified park mode.

LONG linePark(

HCALL hCall,

DWORD dwParkMode,

LPCSTR lpszDirAddress,





A handle to the call to be parked. The application must be an owner of the call. The call state of hCall must be connected.


The park mode with which the call is to be parked. This parameter can have only a single flag set, and it uses the following LINEPARKMODE_ constants:


The application specifies at which address the call is to be parked in lpszDirAddress.


This operation reports to the application where the call has been parked in lpNonDirAddress.


A pointer to a NULL-terminated string that indicates the address where the call is to be parked when using directed park. The address is in dialable number format. This parameter is ignored for nondirected park.


A pointer to a structure of type VARSTRING. For nondirected park, the address where the call is parked is returned in this structure. This parameter is ignored for directed park. Within the VARSTRING structure, dwStringFormat must be set to STRINGFORMAT_ASCII (an ASCII string buffer containing a NULL-terminated string), and the terminating NULL must be accounted for in the dwStringSize. Prior to calling linePark, the application should set the dwTotalSize field of this structure to indicate the amount of memory available to TAPI for returning information.

Return Values

Returns a positive request ID if the function will be completed asynchronously, or a negative error number if an error has occurred. The dwParam2 parameter of the corresponding LINE_REPLY message is zero if the function is successful or it is a negative error number if an error has occurred. Possible return values are:



With directed park, the application determines the address at which it wants to park the call. With nondirected park, the switch determines the address and provides this to the application. In either case, a parked call can be unparked by specifying this address.

The parked call typically enters the idle state after it has been successfully parked and the application should then deallocate its handle to the call. If the application performs a lineUnpark on the parked call, a new call handle will be created for the unparked call even if the application has not deallocated its old call handle.

Some switches may remind the user after a call has been parked for some long amount of time. The application will see an offering call with a call reason set to reminder.

On a nondirected park, if the dwTotalSize member in the VARSTRING structure does not specify a sufficient amount of memory to receive the park address, the corresponding reply message returns a LINEERR_STRUCTURETOOSMALL error value. In such cases, there is no way to retrieve the complete park address. Note that when a LINEERR_STRUCTURETOOSMALL error value is returned, the dwNeededSize field of the NonDirAddress structure does not contain a valid value. If a LINEERR_STRUCTURETOOSMALL error value is received from a nondirected linePark, then increase the size of the buffer and call linePark again until it returns either success or a different LINEERR_XXX result.

See Also


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