Patent ID: 7948995

Claim:
A communication system with an IP transfer network, wherein said IP transfer network includes plural network node apparatuses, a terminal T 1 is connected to a network node apparatus N 1 by a logical terminal LP 1 via a communication line L 1 , and a terminal T 2 is connected to a network node apparatus N 2 by a logical terminal LP 2 via a communication line L 2 , said network node apparatus N 1 has an address management table H 1 being capable of writing and erasing a record, and said network node apparatus N 2 has an address management table H 2 being capable of writing and erasing a record, a request to communicate with said terminal T 2 and a telephone number or host name TN 2 of said terminal T 2 are sent from said terminal T 1 to said network node apparatus N 1 , and based on said request said network node apparatus N 2 sends a receiving notification based on said request to said terminal T 2 , a call-on notification to notify a response preparation starting, is sent from said terminal T 2 to said network node apparatus N 2 , a response notification is sent from terminal T 2 to said network node apparatus N 2 , said network node apparatus N 1 writes a record R 1 in said address management table H 1 , and said network node apparatus N 2 writes a record R 2 in said address management table H 2 , said record R 1 includes an address to discriminate said logical terminal LP 2 , and said record R 2 includes an address to discriminate said logical terminal LP 1 , a communication path P 12 in which an internal packet is transferred is defined between said logical terminals LP 1 and LP 2 , an external IP packet GP 1 of which destination address is an external IP address EA 2 of said terminal T 2 is sent from said terminal T 1 , then said external IP packet GP 1 is inputted to said network node apparatus N 1 via said logical terminal LP 1 , said external IP packet GP 1 is converted into an internal packet NP 1 based on said record R 1 , and said internal packet NP 1 includes said external IP packet GP 1 , said internal packet NP 1 is transferred in said communication path P 12 , and said external IP packet GP 1 restored at said network node apparatus N 2 is sent to said terminal T 2 via said logical terminal LP 2 , and an external IP packet GP 2 includes a communication cut-off request and is sent from said terminal T 1 or T 2 , causing said network node apparatuses N 1 and N 2 to erase said records R 1 and R 2 , and then said communication path P 12 is erased.