To provide a communication system that makes a user using a great amount of sessions unable to use the Internet and provides a user wholesomely using the Internet with a satisfactory service.

A communication system allows users to use the Internet by personal computers 5 in a plurality of dwelling units 2 by introducing a router 8 in a housing complex. The communication system is provided with session number monitoring means 11 which automatically cuts off Internet communication by a personal computer 5 using a great amount of sessions. In addition, the session number monitoring means 11 has a function to inspect the number of sessions by periodically entering the router 8 by remote control.