3.8 Transferring Calls

• Supervised transfer using adiPlaceSecondCall

• Blind transfer using adiTransferCall

1. The application invokes adiPlaceSecondCall.
   AG Access obtains a second line and generates the ADIEVN_PLACING_CALL2 event. AG Access then delivers the second address to the line and monitors the call as described in Section 3.2.
   If AG Access fails to establish the second call, an ADIEVN_CALL2_DISCONNECTED is generated. The port changes back to the Connected state for the first line.
   If the second call is successfully placed, AG Access generates an ADIEVN_CALL2_CONNECTED event. The application is now speaking to the third party (second line destination).
   If the third party hangs up, AG Access generates an ADIEVN_CALL2_DISCONNECTED event, the port transitions back to the Connected state for the first line, and the application resumes speaking with the first party.

2. The application can invoke adiReleaseSecondCall, which causes AG Access to deliver a flash hook to the line and generate an ADIEVN_CALL2_DISCONNECTED event.
   The port changes back to the Connected state for the first line.
   Note: Depending on the PBX or switch, this may result in a three-way conversation.
3. The application can invoke adiReleaseCall, which causes AG Access to send an on-hook to the line interface. The ADIEVN_CALL_RELEASED event is generated and the port changes back to the Idle state. This completes the transfer.

Condition	Description
ADI_XFER_PROCEEDING	The second line's address is delivered to the switch and the transfer is completed as soon as the digit string is dialed.
ADI_XFER_ALERTING	The transfer is completed as soon as the ring tone received on the second line.
ADI_XFER_CONNECTED	The transfer is completed as soon as the second line has been answered.

• If the adiTransferCall option is to disconnect on proceeding, AG Access generates the ADIEVN_CALL_DISCONNECTED event. The application must release the call (as described in Section 3.5) before new calls can be established on the port. Otherwise, AG Access monitors the call as described in Section 3.2.

• If the adiTransferCall option is to disconnect on alerting and AG Access receives ring tone from the PBX or switch, the ADIEVN_CALL_DISCONNECTED event is generated and the application must release the call as described in Section 3.5. Otherwise, AG Access monitors the call.

• If the adiTransferCall option is to disconnect when the second call is connected as described in Section 3.4.1, the ADIEVN_CALL_DISCONNECTED event is generated and the application must release the call as described in Section 3.5.

• If the condition specified in the adiTransferCall function does not occur, AG Access generates an ADIEVN_CALL2_DISCONNECTED event. The port is returned to the Connected state for the first line. This might occur, for example, if the second line is busy.

Call Transfer Event	Description
ADIEVN_PLACING_CALL2	After delivering the flashhook to the line and getting a recall dial tone, AG Access generates the placing second call event. The destination address for the third party is then delivered to the switch.
ADIEVN_CALL2_DISCONNECTED	If placement of the second call fails or if the third-party hangs up, the ADIEVN_CALL2_DISCONNECTED event is generated. The call returns to the connected state for the first call. This event is also generated when the application releases the second call via adiReleaseSecondCall.
ADIEVN_CALL2_CONNECTED	This event is generated if the second call is successfully established via adiPlaceSecondCall. The connection criteria and processing are identical to those when originating calls via adiPlaceCall.
ADIEVN_CALL_DISCONNECTED	The call disconnected event is generated when a blind transfer succeeds. It is also generated if the first line disconnects before AG Access generates the placing second call event. The call disconnected event disconnects the channel from both calls and the application must invoke adiReleaseCall.