lineSetNumRings
The lineSetNumRings
function sets the number of rings that must occur before an incoming call is
answered. This function can be used to implement a toll-saver-style function.
It allows multiple independent applications to each register the number of
rings. The function lineGetNumRings returns the minimum number of all number of
rings requested. It can be used by the application that answers inbound calls
to determine the number of rings it should wait before answering the call.
LONG lineSetNumRings(
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HLINE hLine, |
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DWORD dwAddressID, |
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DWORD dwNumRings |
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); |
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Parameters
hLine
A handle to
the open line device.
dwAddressID
An address on
the line device.
dwNumRings
The number of
rings before a call should be answered in order to honor the toll-saver
requests from all applications.
Return Values
Returns zero
if the request is successful or a negative error number if an error has occurred.
Possible return values are:
LINEERR_INVALLINEHANDLE,
LINEERR_OPERATIONFAILED, LINEERR_INVALADDRESSID, LINEERR_RESOURCEUNAVAIL,
LINEERR_NOMEM, LINEERR_UNINITIALIZED.
Remarks
The lineGetNumRings and lineSetNumRings
functions, when used in combination, provide a mechanism to support the
implementation of toll-saver features across multiple independent applications.
If no application ever calls lineSetNumRings, lineGetNumRings
will return 0xFFFFFFFF.
An
application that is the owner of a call in the offering state and that
received a LINE_LINEDEVSTATE
ringing message should wait a number of rings equal to the number
returned by lineGetNumRings before answering the call in order to honor
the toll-saver settings across all applications. A separate LINE_LINEDEVSTATE ringing
message is sent to the application for each ring cycle, so the application
should count these messages. If this call disconnects before being answered,
and another call comes in shortly thereafter, the LINE_CALLSTATE message should allow the
application to determine that ringing is related to the second call.
If call
classification is performed by TAPI by means of answering inbound calls of
unknown media mode and filtering the media stream, TAPI will honor this number
as well.
Note that
this operation is purely informational and does not affect the state of any
calls on the line device.
See Also