TELECONFERENCING as an alternative to some business travel has gained traction as the air travel experience deteriorated in recent years. But last week, with European airspace shut down by volcanic ash, some companies that were already using teleconferencing found they could use it even more.

The shutdown of air travel affected as many as eight million travelers, leaving a good number still struggling to get back on schedule. It may also result in “permanent structural shifts” in travel behavior, said the Center for Asia Pacific Aviation, an aviation research group. “This event,” it added, “will undoubtedly have the teleconferencing lines running hot, and much of it will persist.”

That was the case at Procter & Gamble, which has 135,000 employees in 80 countries and was an early adopter of teleconferencing. Last week, while many companies rushed to secure teleconferencing capabilities as business travelers were marooned in Europe and around the world, “it was almost business as usual here,” said Laurie Heltsley, the company’s director of global business services.

Emphasis on “almost.” While Procter depends on all kinds of teleconferencing to conduct far-flung business, Ms. Heltsley herself was scheduled to fly to Geneva last week for meetings. The trip was canceled. “So much of what we planned to do in Geneva was going to be ad hoc, involving group dynamics and nonspecific topics” that even the most sophisticated teleconferencing systems can’t substitute, she said.

Even the most ardent proponents of teleconferencing agree that the technology cannot fully, or perhaps even substantially, negate the need for face-to-face contact in business travel. On the other hand, the experience of last week may have raised the bar for evaluating when a trip is necessary and when it can be replaced by a virtual meeting.

We have been reminded repeatedly in the last decade of the vulnerabilities of air travel, starting with the 2001 terrorist attacks in the United States and then the global SARS epidemic scare in 2003. Last week, most of Europe’s flights were dependent on something as seemingly trivial as a “change in the wind” to carry away the volcanic ash, the Center for Asia Pacific Aviation said.

Alternatives like teleconferencing are emerging not just as a way to save money, but also as a backup plan to maintain a global presence in uncertain times.

Among giant corporations, Procter & Gamble has a valuable perspective on teleconferencing because it has been at it for so long.

In early 2007, Procter enlisted Cisco Systems to develop teleconferencing systems at its offices around the world. More than 50 offices have Cisco’s high-end TelePresencing, which uses high-definition video and digital audio to join remote locations in virtual conference room sessions, where participants quickly forget the technology and interact as if they are physically together.

The company also encourages its big customers to use the systems, which it calls video collaboration studios, or to link up in virtual networks using their own systems.

Procter says that teleconferencing of all sorts, from the high-end studios to desktop and other smaller systems for virtual collaboration, replaced an estimated 6,000 international flights in the last six months, with obvious savings in costs along with reductions in carbon imprint.

It is going to be interesting to see how the scales are recalibrated as corporate travel departments absorb the lessons of last week. There is no question that teleconferencing won’t replace business travel by air. And in the short term, air travel may even expand as global industries begin growing again. But it’s clear that teleconferencing of all sorts is now a big part of the mix.

The scramble for teleconferencing alternatives last week was “a confirmation that travel disruptions don’t have to mean business disruptions,” said Bob Kirk, the chief executive of Avistar Communications, which supplies videoconferencing software for desktops and laptops.

As more people become comfortable with doing business by teleconference, business travelers will increasingly be able to say there’s no place like home.

With video technology, Ms. Heltsley said, “You can meet with someone in Singapore in the morning, with someone in Paris at lunch and have dinner with someone in San Francisco.”

Not to mention sleep in your own bed that night.

E-mail: jsharkey@nytimes.com

A version of this article appeared in print on April 27, 2010, on page B6 of the New York edition.