ConnectIncomingCallWithoutInviteAck

The ConnectIncomingCallWithoutInviteAck function allows an application to specify that the VOIP Media Engine should enter the "In Call" state for incoming phone calls even though a final INVITE ACK was not received from the far end of the call. Normally an application does not have to call this API procedure unless the far end SIP device does not handle the SIP protocol properly.

If you are having problems connecting inbound phone calls, you must determine if the far end of the call ever sent the final INVITE ACK SIP message. If it does, you probably have a time-out issue. In that case, you might have to increase the final ACK time-out value using the SetInboundInviteAckTimeout API procedure. If you have determined that the far end SIP device does not transmit final INVITE ACKs properly, you can still get the VOIP Media Engine to connect the incoming call by calling this procedure.

 

Parameters:

hStateMachine

[in] The handle to the telephony engine. This is the handle that was returned by a previous call to the StartSipTelephony procedure.

EnableState

[in] If set to a non zero value, the VOIP Media Engine will ignore the reception of the final INVITE ACK and proceed to connect the inbound call immediately.

Return Value:

If the function succeeds, the return value will be SipSuccess.

If the function fails, the return value will be one of the following values as specified by the TELEPHONY_RETURN_VALUE data type.