AASTRA 4422 IP Office (SIP) for MX-ONE User Guide - Manual (Page 71)

71 Dialog 4422 IP Office
Settings
Settings
Checking the protocol
There are two User Guides for the Dialog 4422 telephone; one
intended for the SIP protocol based telephone, and one for H.323
protocol based telephone. In order to know which User Guide to
use, you need to check which protocol is used in your telephone.
To check the used protocol:
Press the Settings key.
Select the Information menu. The used protocol and the
software version is shown on the display.
Press the C key to return to previous menu.