AASTRA 4420 IP Basic (SIP) for MX-ONE User Guide - Manual (Page 26)

During Calls
Dialog 4420 IP Basic 26
Hold
You can temporarily put the ongoing call on hold. Х Ф
Line/Hold Press the Line/Hold key.
The key lamp flashes slowly.
Note: If you replace the handset, the call is terminated.
Press again to resume the call.
Inquiry
You have a voice connection on Line/Hold and want to make an
Inquiry to an internal or external party. Ô
Line/Hold Press.
The first call is put on hold (Line/Hold flashes slowly). z
Call the third party.
When the other party answers, you can switch between the calls
(Refer Back), Transfer the call, create a Conference or end one of
the calls.
Press to end the Inquiry call.
The third party is disconnected. Ц Ф
Line/Hold Press to return to the first call.
Suffix Dialing (Dialing During Speech)
You want to communicate and control a voice mail system or, for
example, retrieve information through your telephone about your
bank account. 9
Press to activate.