In the hours and days after the Sept. 11 terrorist attacks, millions of phone lines went silent, but e-mail and the Web continued to work.

For years we’ve been hearing about how the Internet was designed to withstand nuclear attacks. Well, at least we know it can resist terrorist bombardment, as was proven on Sept. 11 when the World Trade Center’s collapse took out a massive chunk of Manhattan’s telecommunications capability. Internet service continued uninterrupted after the disaster.

A Verizon switching office that handled 200,000 telephone lines and 3 million data lines was severely damaged by the attack. Its office represented 40 percent of lower Manhattan’s phone lines and 20 percent of the New York Stock Exchange’s phones, according to Associated Press reports. WorldCom and Sprint, which operate much of the Internet’s “backbone” infrastructure, also lost hundreds of high-bandwidth data lines that had passed under the World Trade Center.

But the Internet itself remained strong, as data was routed around the damaged switches and transmission lines, taking alternate paths exactly as its designers intended. The Net’s fundamental communications standard, the Internet Protocol (IP), was created so that packets of data always take the optimum route. If data such as e-mails and page requests can’t take the usual route from point A to point B, they’ll find another way. It may take longer to get there, but the message will still arrive.

The result: In the hours and days after the attack, I found — as did many others — that while phone lines to New York were jammed, people could be reached by e-mail and instant messaging. And while major news sites suffered crushing levels of traffic, the Internet as a whole wasn’t crippled by the surge in usage, according to network monitoring company Keynote Systems. Keynote reported that the performance of the 40 biggest websites was about twice as slow as usual during the week of Sept. 11, but the basic infrastructure of the Net remained sound.

For businesses, that amounts to a ringing endorsement of Internet-based communications. Executives who pooh-poohed instant messaging in the past may find themselves relying on it now, particularly in emergencies where other forms of communication have been shut down or damaged beyond immediate repair.

In the long run, the events of Sept. 11 likely will push more and more companies toward Internet telephony. Voice over IP (VoIP) technologies, which let you place telephone calls using the Internet’s infrastructure, now look better than ever. I’m talking not about consumer-oriented Internet phone services but about full-blown corporate telephone systems (from the likes of Cisco (CSCO), Lucent (LU), Nortel (NT), and 3Com (COMS)) that are based on IP and route voice calls through your existing data network. With the right setup, you could still place calls to co-workers even if one or two or a dozen major telecommunications lines are broken.

Companies also are already conducting an increased amount of business remotely, using teleconferencing and videoconferencing systems. That bodes well for streaming-media technologies, which digitize video and audio streams for real-time transmission over the Internet (corporate vendors of these technologies include Microsoft (MSFT), PictureTel (PCTL), and Polycom (PLCM)). With air travel increasingly inconvenient — not to mention nerve-racking — it’s a good time to take a hard look at whether in-person meetings are really necessary. When they aren’t, why not do a videoconference instead? This could also be useful on those days when employees can’t make it to the office: With video-ready laptops, they can teleconference from their homes instead.

These are expensive systems, to be sure, and with IT budgets in limbo you probably won’t be rushing out to buy one tomorrow. But when spending picks up again, VoIP should be at the top of your shopping list. For one thing, it is a smart addition to the investments in Internet infrastructure that you’ve been making for the past five years. VoIP systems will also be easier to integrate with the IP-based networks that the big telecommunications companies are building right now. And they promise to cut long-distance charges as well as introduce a new level of reliability into your phone system. Internet-based videoconferencing offers similar cost and reliability advantages, although for most companies it will be a lower priority.

But one thing is certain — companies will be renewing their interest in communications technologies that are robust enough to keep working during a crisis. Suddenly the Internet’s messy, decentralized infrastructure is looking pretty good.

Has your company’s Internet communications strategy changed since Sept. 11? Write to me at

Link: Internet Emerges as the Most Reliable Way to Communicate

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