To process a large number of requests which are simultaneously received from plural client devices by storing temporarily the requests sent to a server from the client devices and controlling the number of requests to be sent to the server in response to the load state of the server.

A line concentration conversion device 101 is placed between plural client devices and a server 110 to connect the local area networks or wide area networks to each other. The server 110 accepts the requests from the client devices in a network and performs the services and sends these service results back to the client devices. Then the device 101 temporarily stores the requests given to the server 110 from the client devices in a request temporary storing buffer 102. Meanwhile, a load state monitoring part 106 periodically monitors the load state of the server 110, and a flow control part 105 controls the number of request packets to be sent to the server 110 in response to the monitored load state of the server 110.