Researches on the wireless mesh network in which access points (APs) of a wireless LAN are connected by an ad-hoc networks are recently drawing much attention. In the wireless mesh network, APs can be set up freely and its areas can be expanded easily. For the wireless mesh network, methods of utilizing multiple gateways (GWs) at the time of making a connection with an exterior network such as the Internet have been studied in order to resolve the congestion problem around GWs, which is the bottleneck in gaining a high throughput. Although a method of distributing packets to dierent GWs has been studied hitherto, the method tend to lower the communication throughput due to the function of TCP's congestion control. Thus, we propose a method of utilizing GWs eeciently by distributing packets to multiple GW "in units of session" (i.e. one of GWs is selected session by session). This method does not give any inuence on the throughput of TCP communication. By conducting a...