COMMUNICATION DEVICE, SERVER, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD

摘要

The present invention provides a communication device on a local area network (LAN) which performs NAT traversal by a LAN router, the communication device being connected to a server via an external network, wherein the communication device has a LAN configuration determination unit for determining the configuration of the LAN router, and a communication device-side communication control unit for requesting, when it is determined that the LAN router is configured in two or more stages, that a NAT update request packet be transmitted at a prescribed interval to a router, registered in the server, that performs NAT traversal.