V8: Advanced - SIP/RTP (Tab) - SIP(Section): Release Transferred Party On
When a call is transferred, the transferred party sends notifications to the transferring party about the progress of the call towards the transfer target. The notifications include the current SIP response code received by the transferred party. This settings specifies at which point the transferring party will release the transferred call. This occurs when the reported SIP response code is equal to or greater than the value of this setting. This setting should be administered in tandem with the setting retrieve_xferred_call_on.
Note that when marking a call with save transfer the phone will ignore the actual setting value and instead act as if this was set to 200.
If the value is set to empty, the phone will release the call just after sending the REFER. The empty value is supported since version 10.1.39.0
any SIP response code in the provisional (1xx), successful (2xx), and redirection (3xx) response range, and empty