Spiros.. B&O mentioning that the BeoCom 5 can be used as a VoIP phone is pure marketing blabla. The BeoCom 5 is as VoIP compatible as the BeoCom 6000, BeoCom 2... or any other analogue phone.
To clear things up: The BeoCom 5 has the ability to have 2 normal PSTN lines. So.. If you use an ATA (analogue telephone adapter) then it can be used in a VoIP setup. But in this case you'll have to configure the ATA and not the BeoCom5. There is no way to configure the BeoCom 5 in an IP setup.
IF B&O made it real IP compatible with a descent ATA inside the phone and a RJ45 connection they would sell a shitload of these phone. But alas... it's just a normal analogue phone.
The race for quality has no finish line- so technically, it's more like a death march.