COMMUNICATION NETWORK SYSTEM AND COMMUNICATION APPARATUS

摘要

The present invention provides a communication network system in which communication can be securely performed via a global network from an existin g terminal apparatus to an existing device connected to a local network withou t needing a special gateway function in a router and without performing a special setting in the router. In the communication network system (10), a communication relay client (202) performs polling on a management center network (1) via a NAT router (204); a communication relay server (102) converts a packet transmitted from a management terminal (101); and the communication relay client (202) receives the converted packet as a response to the polling via the NAT router (204) from the side of the management cent er network (1). The communication relay client (202) converts the converted packet to the original packet, and transmits the original packet to a device to be managed (201).