lineSetCallParams function (tapi.h)

Article
02/22/2024

The lineSetCallParams function allows an application to change bearer mode and/or the rate parameters of an existing call.

Syntax

LONG lineSetCallParams(
  HCALL                  hCall,
  DWORD                  dwBearerMode,
  DWORD                  dwMinRate,
  DWORD                  dwMaxRate,
  LPLINEDIALPARAMS const lpDialParams
);

Parameters

hCall

Handle to the call whose parameters are to be changed. The application must be an owner of the call. The call state of hCall can be any state except idle or disconnected.

dwBearerMode

New bearer mode for the call. This parameter uses one and only one of the LINEBEARERMODE_ Constants.

dwMinRate

Lower bound for the call's new data rate. The application can accept a new rate as low as this one.

dwMaxRate

Upper bound for the call's new data rate. This is the maximum data rate the application can accept. If an exact data rate is required, dwMinRate and dwMaxRate should be equal.

lpDialParams

Pointer to the new dial parameters for the call, of type LINEDIALPARAMS. This parameter can be left NULL if the call's current dialing parameters are to be used.

Return value

Returns a positive request identifier if the function is completed asynchronously, or a negative error number if an error occurs. The dwParam2 parameter of the corresponding LINE_REPLY message is zero if the function succeeds or it is a negative error number if an error occurs. Possible return values are:

LINEERR_BEARERMODEUNAVAIL, LINEERR_NOTOWNER, LINEERR_INVALBEARERMODE, LINEERR_OPERATIONUNAVAIL, LINEERR_INVALCALLHANDLE, LINEERR_OPERATIONFAILED, LINEERR_INVALCALLSTATE, LINEERR_RATEUNAVAIL, LINEERR_INVALPOINTER, LINEERR_RESOURCEUNAVAIL, LINEERR_INVALRATE, LINEERR_UNINITIALIZED, LINEERR_NOMEM.

Remarks

This operation is used to change the parameters of an existing call. Examples of its usage include changing the bearer mode and/or the data rate of an existing call.

Requirements

Requirement	Value
Target Platform	Windows
Header	tapi.h
Library	Tapi32.lib
DLL	Tapi32.dll