An IP based voice/video communication system and call pickup/forwarding method and a program storage device, readable by a machine, tangibly embodying a program of instructions executable by the machine to perform the call pickup/forwarding method enables a subscriber can have voice/video communication...http://www.google.fr/patents/US7656889?utm_source=gb-gplus-shareBrevet US7656889 - IP-based voice/video communication system and call pickup/forwarding method
IP-based voice/video communication system and call pickup/forwarding method
