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Internet connectivity to the hosts PingER monitors in Japan was maintained. Round Trip Times (RTT) to some hosts increased significantly as seen from SLAC. However as seen from RIKEN in Japan they did not increase. It appears the increase in RTT depends on the route from the monitoring host to Japan. This suggests a possible cable disruption. For more on cables see here.
While the The Japanese Internet appears to have kept running remarkably well (though some end hosts were not reachable a day later), the though one of the 6 end hosts monitored did go down for some time after the earthquake. This compares well with the impact of the Chilean earthquake on the hosts monitored in Chile in February 2010 in which both hosts monitored in Chile were not reachable following the earthquake. One was again reachable a few hours later, the other was not reachanle until March 3rd 2010. The Japanese phone network did not fare so well as its Internet.
PingER results
All of the 6 hosts that PingER monitors in Japan stayed up at the time of the earthquake. The hosts monitored are seen in the table below.
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