Patent ID: 7984164

Claim:
A server including a hardware processor that relays packet data transmitted and received between a first terminal and a second terminal among a plurality of terminals, the server comprising: a transfer table storing unit configured to store a transfer table in which a connection address pair, comprising a first connection address and a second connection address, is registered; and a connection establishment message processing unit configured to transmit a SYN ACK message as a response message to a SYN message, upon receiving the SYN message, for establishing a TCP connection from each of the first terminal and the second terminal, wherein the first connection address is used to connect the server and the first terminal and the second connection address is used to connect the server and the second terminal, wherein, upon receiving the SYN message from the first terminal or the second terminal by using the first connection address or the second connection address, respectively, the connection establishment message processing unit generates a first SYN ACK message and transmits the first SYN ACK message by using the first connection address, and generates a second SYN ACK message and transmits the second SYN ACK message by using the second connection address, wherein the first SYN ACK message includes first TCP option information that is included in the SYN message received by using the second connection address of the connection address pair, and wherein the second SYN ACK message includes second TCP option information that is included in the SYN message received by using the first connection address of the connection address pair, wherein the first connection address includes an IP address and a port number of the first terminal, and an IP address and a port number of the server, and wherein the second connection address includes an IP address and a port number of the second terminal, and the IP address and the port number of the server.