| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a head end apparatus for use in a VoIP (voice over Internet protocol) network which uses an MGCP (media gateway control protocol) to provide a VoIP service for many subscribers using data communication terminals together with VoIP terminals. <P>SOLUTION: The head end apparatus has a DHCP (dynamic host configuration protocol) server for assigning a private IP address, a router for blocking an IP packet, and an MGCP NAT (network address translator) router which transmits a received IP packet to the Internet by changing a source IP address of the IP packet to an authorized IP address while assigning a new UDP (user datagram protocol) port number when receiving the IP packet having the UDP packet with the destination IP address identical to the IP address of a gateway, from a VoIP terminal, registers the IP address and the UDP port number in a translation table, and transmits the IP packet by changing the destination IP address and the UDP port number to a registered private IP address and a registered UDP port number. <P>COPYRIGHT: (C)2004,JPO</p> |
