NETWORK REPEATER, DATA COMMUNICATION SYSTEM, DATA COMMUNICATION METHOD AND PROGRAM MAKING COMPUTER PERFORM THE METHOD

摘要

PROBLEM TO BE SOLVED: To facilitate the mounting and management of a function performing IPSec communication inside and outside a private network and to reduce the cost. SOLUTION: A network repeater 7 performs the repeating processing of a packet between the private network 3-1 and an outer network 2, where unique private addresses are used in self-private networks. The repeater has a first repeating part encapsulating an ESP packet transmitted within the private network 3-1 into a UDP packet and repeating it to the outer network 2 and a second repeating part decapsulating the UDP packet from the outer network 2 into the ESP packet and repeating it into the private network 3-1.