Sandy Doubled US Internet Outages
Internet outages on the East Coast of the U.S. before and after Superstorm Sandy made landfall in New Jersey.
CREDIT: John Heidemann
Failed Internet connections in the U.S. doubled after Superstorm Sandy made landfall, new research has found. Many of those lost connections occurred in New York and New Jersey.
"On a national scale, the amount of outage is small, showing how robust the Internet is," the lead researcher in the work, computer scientist John Heidemann, said in a statement. "However, this significant increase in outages shows the large impact Sandy had on our national infrastructure."
Heidemann and his colleagues at the University of Southern California (USC) hope that the method they used to track connections during Sandy may one day work to monitor the state of the Internet around the world in near-real time. "We hope that our approach can help first responders quickly understand the scope of evolving natural disasters," Heidemann said.
The day before Sandy made landfall, about 0.2 percent of Internet connections in the U.S. were down, Heidemann and his colleagues found. (On an average day, about 0.3 percent of U.S. connections are down for one reason or another, the researchers said). Once the storm hit, however, the outage number leaped to 0.43 percent of U.S. Internet connections, with much of the increase borne by New York and New Jersey. It took two days for the national Internet outage rate to return to about 0.3 percent and four days to reach 0.2 percent, the USC team found.
Heidemann's lab measures Internet outages by pinging networks and waiting for a reply. Those that reply consistently for days and then stop have gone down. Lab members are also able to see the duration of outages, and found that New Jersey and Connecticut seemed to repair their networks faster than New York did.
Not all networks will reply to Heidemann's pings. Firewalled networks don't reply, but Heidemann has conducted other research showing that there are enough nonfirewalled networks that his method should give a reasonable picture of the state of the Internet over the entire U.S.
During and a few days after Sandy, Renesys, a company that conducts research into the global Internet, also published its own figures about network outages in the areas affected by Sandy. Heidemann and his colleagues found higher figures than Renesys analysts did, but the numbers aren't directly comparable because Renesys used a different technique for its measurements, the USC scientists wrote in a paper. (Neither the USC nor the Renesys figures are peer-reviewed.)
Seeing the global state of Internet connections gives computer scientists a way to monitor natural disasters, even if the scientists are distantly located, safe in their laboratories, Heidemann thinks. "Our work measures the virtual world to peer into the physical," he said.