2013 Volume 21 Issue 1 Pages 29-34
Server Ping Map, a system to monitor reply from public internet servers and to map the monitoring results on the Digital Japan Map System, was developed in order to detect unusual situation. A method to select position-known servers is also proposed. Therefor we can graphically grasp unusual locations. When we estimate earthquake damaged area, the estimation will be wrong, if (1) communication lines through the damaged area are physically destroyed, (2) traffic in non-damaged areas is selectively congested, or (3) servers in non-damaged area are suffered by power failure which caused by accident(s) in damaged are far from the servers.