I have a VOIP phone system ( Bizfon 6800 ) that uses multicast packets to send telephone line status out to the IP phones on the network.
I am working on allowing our PPTP roadwarriors to take an IP phone and install it behind a hardware PPTP client( SnapGear ).
This way they would be able to use the IP phoneset in a remote location and still have the benefit of using the home office's long distance lines, voice mail, etc.
