Auto answer calls

Hi support,

It is possible to send a call to a yealink device (example T20P) autoanswer the call with SIPAddHeader(Alert-Info: <http://localhost/>;info=alert-autoanswer);
and if the device is in an active call interrupts this call and plays the send call in the speaker ?

I already send the call and autoanswer it, but if the device is busy the calls end without being play

Thanks in advance