SAN FRANCISCO -- According to Vonage Holdings Corp. CEO Jeffrey Citron, intentional blocking of Voice over IP traffic is more than just a competitive dirty trick -- it's an act of censorship against free speech.

In an exclusive interview here Tuesday [March 1], Vonage's chief executive said the issue of the company's recent incident of having some VoIP traffic blocked reaches beyond the market for IP-based voice communications and into the realm of free speech -- and as such, should be protected by the courts, the FCC, or by new telecom regulation that ensures free and open access over the Internet.

"What is this [port blocking] really all about?" said Citron, who was in San Francisco Tuesday for the Reuters Technology Summit. "It's really censorship in a way."

Though Citron would not identify the ISP that Vonage is claiming to have blocked its VoIP service, he did provide some additional details about the incident, as well as some opinions on where the online world might be headed if technologic tactics like port blocking or traffic manipulation are not actively discouraged or made illegal.

The advanced features of network analyzers, Citron said, already allow administrators to look not only at what types of packets are traversing their networks, but into the actual content of the packets. Port blocking of VoIP traffic, he opined, is a step down a slippery slope that could lead to network owners blocking content or Web sites they disagreed with.

"What happens if [network operators] use technology to peer into your packets and read and see what you're doing?" Citron asked. "If they have a particular view of the world, they could just stop any news article that purports to go against that view. If they're [already] looking in the packets for SIP, or for instant messaging, where does the line end?"

As to the incident that Vonage complained to the FCC about, Citron said the company first heard from Vonage customers in late November of 2004 that their Vonage service wasn't working. After normal tech support couldn't figure out the problem, Citron said Vonage put its best technicians on the case, and what they found was puzzling.

The engineers, Citron said, "could talk to the [customer's] box, but the box couldn't talk to [Vonage's] server, and it only couldn't talk SIP. We thought, Ah! There must be something going on here. So my guys just changed the SIP ports to something different, and 'schwing!' The service worked just fine."

Citron also said that some of Vonage's customers involved in the incident called their ISP, which admitted it was blocking Vonage.

"They [the ISP] came out and said [to the customers] 'yes, we are doing this.' So there is no dispute," Citron said. "We were intentionally, willfully, blocked."

While Citron doesn't quite know what the next step will be, he is hoping that the FCC uses some of the enforcement tools at its disposal to strongly discourage the practice of using networking technology to selectively block, alter or impede Internet traffic. Since Vonage has not filed a formal complaint with the FCC, the details of the investigative and potential punitive processes are not clear.

"The FCC could come out and institute the largest possible fine they could, with the sternest of statements saying, 'this will not be tolerated,' " Citron said. "That might send a strong enough message."

If the FCC decides against quick action, Citron said the next step might be a formal rule-making process by either the FCC or Congress, a step that could be a slow one given that the FCC is about to undergo a change of leadership, and that any Congressional telecom legislation may be years away at best.

"It'd be unfortunate to have to pass a law [against port blocking and other types of interference], but we may have to," Citron said. Though he said he has previously testified against the need for port-blocking regulation, Citron may now change that tune, especially if more network operators start using port-blocking or other techniques to selectively control Internet traffic.

"Until a market becomes free and becomes developed, sometimes you may have to put in place government regulations that allow for the market to develop," said Citron. "We may need to come up with a set of principles, for broadband, going forward."

The tenets of free speech, Citron said, are a good place to start that process, and should be used to help resolve Vonage's recent incident.

"What are people using broadband to do? Communicate," Citron said. "They [network operators who block VoIP] are restricting your ability to communicate with another person. And that's censorship."