Make sure you have a good VoIP service provider that offers free tech support

should your provider support it it works really well

should your provider support it it works really well

I'm using this phone on an internal network provided by a Mikrotik Routerboard 2011UiAS-2HnD-IN; the phone is registered to an Asterisk PBX CentOS 6.5 virtual machine (which supports the G722 codec) and my VoIP provider is Callcentric (who also supports G722).It's very network-dependent, but for my setup the voice is crystal clear