Is a diagram of an IP telephone system connected to a wide area network through a gateway. The IP phones are connected to the Local Area Network. Voice calls can be made locally over the Local Area Network. The IP phones include codec's that are digitize by encoding and decoding the speech. The IP phones can also help packetize and depacketize the encoded speech into IP packets. Calls between different geological locations can be made over the wide area network. Connections to the PSTN can be established through VoIP gateways.