said by neftv:Yes. But GV has it implemented the way they have it.
It doesn't matter how the calls are implemented. The services don't have to comply with SIP, and yet be VoIP, i.e. MGCP, Skype, H323, etc. What matters here is if GV service is a VoIP or not. I would rather agree with Nitzan; however, knowing what VoIP and/or GV services are, it will be hard for me to admit that GV services are not VoIP.