A process for preparing a polyether ether ketone. The ADC detects the received traffic as an attack traffic, the received traffic being intended for routing through software defined network switches. The server-client type surgical robot system can include a plurality of control clients for manipulating one surgical server, and incorporates security technology in server-client based robot surgery, to allow greater safety in performing surgery. During an Internet Key Exchange communication that is performed prior to the IPsec communication, the security gateway apparatus integrates a Dynamic Host Configuration Protocol communication option into an IKE data, and designates the IP address of the outside PC from a tunneled IP packet.