Abstract
IPTV service is widespread recently. First, download time and download quantity in a given time was measured when video file was downloaded simultaneously by PCs. The results show that download time with single PC is slower than multiple PCs when when the file formatl is downloaded with HTTP. Because single PC with HTTP downloaded at regular intervals. Switching time to another channel was measured. The results show that the switching time equalled buffer time plus one to three minutes when buffer time is ten secondes or more. When buffer time is ten or less, switching time is almost the same.