Tools and techniques for synchronous design communication are still underdeveloped, because insufficient bandwidth of the present Internet has inhibited practical experiments. Reviewing the results of a design communication test carried out by the authors using a TCP/IP based V-LAN on ATM network, this paper discusses the proposal that synchronous communication using application sharing tools and video conferencing tools will become common in the broadband network age, in addition to the use of bulky data on remote PCs or web databases.