ISPs must learn from 11 September, says report

The internet sustained relatively little damage during the terrorist attacks on 11 September last year, when the collapsing World Trade Center destroyed lower Manhattan's communications networks, according to a new report.

The National Research Council's report, however, warns that internet service providers must prepare for future emergencies.

The attacks have forced businesses and government agencies to reevaluate how they structure computer networks, data back-up centres and links to the internet.

Telephone service was greatly affected in parts of lower Manhattan on 11 September, while mobile phone service suffered more widespread congestion problems, according to the report. Nearly one-third of Americans had trouble placing a phone call on the day of the attacks. The internet, however, experienced only small problems with overall connectivity and data loss.

Because of its resilience, the report noted, the internet was enlisted as a tool in the rescue and recovery efforts. Some individuals used instant messages on their wireless handheld devices and phones to communicate. Websites were created to distribute lists of missing persons.

New York City is a densely packed communications hub, with private data networks and public networks criss-crossing below the city's streets. And many trans-Atlantic cables come ashore near the city, bringing internet traffic from Europe.

Although the effect of the attacks may not reflect how the internet would respond during any future attacks, they do shed light on possible vulnerabilities, the report says. Key businesses and services that use the internet should review their reliance on the network and plan alternative communications strategies during emergencies, for example.

The council is a private, non-profit institution that provides science and technology advice under congressional charter. It works with the National Academy of Sciences and the National Academy of Engineering. Study sponsors included IBM and the Association for Computing Machinery.

Sandeep Junnarkar writes for CNET News.com.