The Federal Communications Commission reported 25% of cell towers in 10 states hit by Sandy were affected by the storm, and more than a quarter of land lines experienced outages along the Northeast coastline, from Virginia to Massachusetts. However, that figure had fallen to 22% by late Wednesday, the FCC said.
Keynote reported that "almost everyone in and around New York City" experienced either full-scale outages of their Internet connectivity or sporadic performance issues.
Keynote's services connect to the Internet through AT&T, Verizon, Sprint and T-Mobile networks. The monitoring service said it experienced significant slowdowns or complete service interruptions, as cell towers were affected by power outages and by a surge of voice and data traffic.
"This is true for both Internet users of both land line high-speed Internet connections or those accessing the Internet through their mobile phones," Keynote stated.
While overall the Internet weathered Hurricane Sandy, Keynote stated there are still "lessons to be learned."
"First, it is critically important to build robust business continuity plans around your online presence," it stated. "This means having your online content and websites available from multiple data centers, in different parts of the United States or world, as well as implementing technologies to allow for quick failover to those redundant data centers.
Keynote also suggested that businesses test contingency plans regularly, with a special emphasis on making sure users can connect to their sites via mobile phones and Web browsers.
"Finally, recognize the fragility of the mobile Web," Keynote stated. "In highly dense populations, even a single mobile cellular tower taken offline can wreak havoc for everyone in that area."
Lucas Mearian covers storage, disaster recovery and business continuity, financial services infrastructure and healthcare IT for Computerworld. Follow Lucas on Twitter at @lucasmearian, or subscribe to Lucas's RSS feed. His email address is email@example.com.