VOIP Phone - a new era of productivity?

I have a new phone on my desk. It's black and shiny, has lots of buttons and I can't figure it out at all.

There are bits of functionality I have discovered though. It makes calls, but that's just dull. It also has a (programmable) button which lets me permanently set my phone to busy (as in engaged) for some lovely peace and quiet. It has an auto-answer function: if someone calls me the phone rings once then answers itself putting them on speakerphone. Then I can shout vaguely in the direction of the phone and they can shout back at me thus allowing us to have a barely adequate conversation AND annoy the office at the same time, or allow people to ring your desk and shout helplessly because you're off having coffee. What larks.

However the very best function (so far) is the "page another phone" option which lets you speak directly through another phone's speakerphone speaker, regardless of whether that person wants you to or not, or indeed if they are currently speaking on the phone. So you can page ANY of these phones in the university and shout at the person sitting at the desk and they can do NOTHING to stop you, other than call security. Thus far I have found no way to override this option and lock my phone down.

Truly the days when your desk phone was your friend are long gone. I strongly suspect the person who designed this beast has never worked in an office.