INTRODUCTION
Broader bandwidth and a wide variety of communication methods on the Internet have brought us smooth and efficient
communication in real time between several sites simultaneously. However, the tools realising such communication are not yet mature, especially if the tools have state of the art functions, such as the multipoint communication which enables a tele-conference. We have considered that the utilization of a sub-channel is a key factor for making communication effective. So this paper reports our trial of multi-channel communication and the results of an analysis of its efficiency.