TSPI_lineSendUserUserInfo function (tspi.h)

Article
10/05/2021

The TSPI_lineSendUserUserInfo function sends user-user information to the remote party on the specified call.

Syntax

LONG TSPIAPI TSPI_lineSendUserUserInfo(
  DRV_REQUESTID dwRequestID,
  HDRVCALL      hdCall,
  LPCSTR        lpsUserUserInfo,
  DWORD         dwSize
);

Parameters

dwRequestID

The identifier of the asynchronous request.

hdCall

The handle to the call on which to send user-user information. The call state of hdCall can be connected, offering, accepted, or ringback.

lpsUserUserInfo

A pointer to a null-terminated Unicode 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).

dwSize

The size, in bytes, including the null terminator, of the user-user information in lpsUserUserInfo.

Return value

Returns dwRequestID, or an error number if an error occurs. The lResult actual parameter of the corresponding ASYNC_COMPLETION is zero if the function succeeds, or an error number if an error occurs. Possible return values are as follows:

LINEERR_INVALCALLHANDLE, LINEERR_OPERATIONFAILED, LINEERR_INVALCALLSTATE, LINEERR_RESOURCEUNAVAIL, LINEERR_NOMEM, LINEERR_USERUSERINFOTOOBIG, LINEERR_OPERATIONUNAVAIL.

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 breaking the information up into a sequence of chained network messages (using "more data").

User-user information can also be sent as part of call accept, call reject, call redirect, and when making calls. User-user information can also be received. The received information is reported in the call's LINECALLINFO structure. Whenever user-user information arrives after call offering or prior to call disconnect, a LINE_CALLINFO message with a UserUserInfo parameter notifies TAPI 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 TAPI.

Requirements

Requirement	Value
Target Platform	Windows
Header	tspi.h