Texas Attorney General Greg Abbott yesterday filed a lawsuit against Vonage, claiming the leading voice-over-IP provider deceives customers by failing to communicate that its voice service does not include access to the E-911 system associated with traditional telephone service.

Abbott’s action comes in the wake of a much-publicized incident in Harris County last month, when Joyce Johns was unable to call 911 from the family’s Vonage phone after her parents suffered multiple gunshot wounds. The lawsuit seeks injunctive measures to stop Vonage from allegedly misrepresenting the emergency telephone services it offers and the fact that 911 service is not offered automatically to Vonage customers. The suit seeks $20,000 per violation.

“This family’s moment of crisis signals a dire need for Vonage to clearly communicate to its Internet telephone customers that 9-1-1 access may not be available to them,” Abbott said in a prepared statement. “This is not just about bad customer service; it’s a matter of life and death.”

Vonage spokeswoman Brooke Schulz said her company had received the lawsuit and plans to work with Abbott’s office.

“We are working with the attorney general to resolve this issue in an expedient manner,” Vonage spokeswoman Brooke Schulz said. “We do a lot of disclosure already, but we’re looking forward to working with the attorney general to learn what he’d like us to improve. We’re always open to discussion.”

The Minnesota state commission’s effort to require Vonage to provide E-911 service was overturned by a federal district court. An appeal of the case effectively was derailed by the FCC, which asserted that VoIP providers are subject to federal jurisdiction.

However, that FCC order indicated that states could still play a role in terms of fraud and consumer protection. The Texas lawsuit was filed under the Texas Deceptive Trade Practices Act.

“This suit is not requiring Vonage to do anything,” a spokesman in the Texas Attorney General’s office said. “This is about deceptive trade practices.”

In most states, Vonage offers a form of 911 service, but calls typically are routed to the administrative offices of a public-safety answering point (PSAP) instead of connecting directly to a dispatcher. To receive the service, customers must subscribe to the option and manually update the location of their phone to assure that the call is sent to the appropriate PSAP.

Vonage, which boasts more than 500,000 subscribers, recently announced it is providing E-911-type services in Rhode Island, where the PSAP’s selective router is owned by the government and not a telecom carrier.