A communication traffic control system of this invention is directed to reduce traffic on a LAN. In LAN (1) of a CSMA/CD type having a server computer (2), a first client computer (3), a second client computer (4) and other third, fourth . . . client computers connected thereto, when the first client...http://www.google.de/patents/US7032004?utm_source=gb-gplus-sharePatent US7032004 - Communication traffic control system on LAN, communication traffic control method and recording medium storing communication traffic control program