lineSendUserUserInfo function (tapi.h)
The lineSendUserUserInfo function sends user-user information to the remote party on the specified call.
Syntax
LONG lineSendUserUserInfo(
HCALL hCall,
LPCSTR lpsUserUserInfo,
DWORD dwSize
);
Parameters
hCall
Handle to the call on which to send user-user information. The application must be an owner of the call. The call state of hCall must be connected, offering, accepted, or ringback.
lpsUserUserInfo
Pointer to a string containing user-user information to be sent to the remote party. User-user information is only sent if supported by the underlying network (see LINEDEVCAPS). The protocol discriminator field for the user-user information, if required, should appear as the first byte of the buffer pointed to by lpsUserUserInfo, and must be accounted for in dwSize.
dwSize
Size of the user-user information in lpsUserUserInfo, in bytes.
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_INVALCALLHANDLE, LINEERR_OPERATIONUNAVAIL, LINEERR_INVALCALLSTATE, LINEERR_OPERATIONFAILED, LINEERR_INVALPOINTER, LINEERR_RESOURCEUNAVAIL, LINEERR_NOMEM, LINEERR_USERUSERINFOTOOBIG, LINEERR_NOTOWNER, LINEERR_UNINITIALIZED.
Remarks
This function can be used to send user-user information at any time during a connected call. If the size of the specified information to be sent is larger than what can fit into a single network message (as in ISDN), the service provider is responsible for dividing the information into a sequence of chained network messages (using "more data").
User-user information can also be sent as part of call accept, call reject, and call redirect, and when making calls. User-user information can also be received. The received information is available through the call's call-information record. Whenever user-user information arrives after call offering or prior to call disconnect, a LINE_CALLINFO message with a UserUserInfo parameter notifies the application that user-user information in the call-information record has changed. If multiple network messages are chained, the information is assembled by the service provider and a single message is sent to the application.
This function may send data over the wire in unencrypted form; therefore, someone eavesdropping on the network may be able to read the data. The security risk of sending the data in clear text should be considered before using this method.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Windows |
| Header | tapi.h |
| Library | Tapi32.lib |
| DLL | Tapi32.dll |