Some voice-over Internet protocol subscribers calling for help in an emergency weren't getting it, but the Federal Communications Commission may have responded a little too quickly for at least two companies.

Because many subscribers haven't acknowledged the limitations put on 911 calls made via VoIP, the VON Coalition, consisting of AT&T (NYSE:T) and MCI (NASDAQ:MCIP), was able to convince the FCC to delay forcing them to disconnect those subscribers, which could have cost the companies millions of dollars.

On Friday, the FCC showed it agreed with the coalition's argument by granting a 30-day extension to the companies, as many of the VoIP subscribers hadn't replied by the first deadline.

According to an FCC ruling, subscribers to VoIP who have not responded to a 911 rule were to have their service shut off on Aug. 29. Reacting to some troubling incidents when authorities contacted over VoIP were unable to locate the emergency, the FCC had enacted a rule saying that all 911 emergency calls would go directly to emergency dispatchers and provide the location of callers by late November.

In the meantime, the FCC asked that customers confirm that they acknowledge the current limitations of VoIP. These customers were to submit a response by Aug. 29 that indicated that they understood that not all 911 calls made on VoIP would go immediately to dispatchers. If they didn't comply, their service would be terminated.

The VON Coalition then petitioned the FCC, claiming that disconnecting customers would cause more harm than good. The argument was that even if the VoIP did not directly provide the location, disconnecting customers would give them even less means of contacting authorities in case of an emergency. While this argument is certainly logical, it does not remedy the problem.

Disconnecting these customers would also be a major step back in subscriber growth of this emerging technology.

AT&T and MCI's resolve not surprising. There are an estimated 2.5 million VoIP subscribers in the U.S., representing a huge amount of revenue to these companies.

While the VON coalition and other Internet telephone companies may be breathing easy again for another month, they must be more proactive about getting their customers to respond, because the FCC isn't likely to continue extending the deadline. The issue will likely be moot by the end of November; VoIP will become integrated with 911 dispatchers by then. In the meantime, if AT&T and MCI wish to keep their subscribers, they have to find ways to make them respond.

Fool contributor Tarek Sultani is a freelance journalist. He does not have a financial interest in any of the companies mentioned in this article and welcomes feedback.