Aircell: On U.S. Planes, VoIP Will Be Muted

Ever since my troublemaker friend Andy Abramson figured out a way to make VoIP calls over GoGo, the in-flight broadband system from Aircell, there has been a flurry of activity leading to the banning of some of the services Andy used.

Andy’s experiment came close on the heels of GoGo’s commercial launch on Aug. 20 on American Airlines. When I asked an Aircell spokeswoman if this was mostly an issue of limited bandwidth availability — after all, the Aircell system does rely on a cellular network — she said that wasn’t the case. “The carriers and Aircell have taken a position on this because we don’t want people talking on the plane.” The company also sent me an official statement reiterating its anti-VoIP position:

“It is against American’s policy and Gogo’s terms of service to use VoIP. Aircell has multiple protocols and practices in place to prevent the use of VoIP. Obviously, it is extremely difficult to stop every instance of VoIP but Aircell is monitoring and working constantly to enforce American’s policy and Gogo’s terms of service.”

The spokeswoman said that the company is not blocking any content, but at the same time “we are doing our best to make VoIP services unusable.” Aircell can block the pure-play VoIP services because VoIP calls typically use a protocol called UDP. Dan York, CTO of Voxeo, has a great post explaining how VoIP works. In comparison, it is much harder to block calls that use the web and TCP protocol. York explains that is why Andy was able to make a call using a web-based system like Phweet. It didn’t use UDP.

Does that mean they will block all web services that use Flash for voice connections? Will this include blocking IMO.IM or Tokbox? What about voice chat on other social networks? Where does it all stop? My friend Aswath thinks that Aircell’s approach will be very much like YouTube, where a video that infringes copyright is disabled if someone brings it to the company’s attention. The first victim of that policy might be TringMe, a VoIP provider with a push-to-talk-type service that uses Flash. An Aircell spokeswoman told me that you can see the TringMe web site but can’t really use the service.

What that means is that Flash objects would work in a web browser, but it will be hard to make and receive calls. “Aircell’s network-monitoring software can allow those one-way streams of network traffic while blocking streams of traffic that fit the profile of two-way VoIP conversations,” York wrote in a private email. Such one-way Flash traffic could include streaming videos and even music.