The carriers are busy piling onto Vonage, first Verizon, then Sprint now ATT:
In a filing with the U.S. District Court for the Western District of Wisconsin, AT&T alleged that Vonage wilfully infringed an AT&T patent related to telephone systems that allow people to make VoIP calls using standard telephone devices.
According to Vonage SEC filings:
The complaint relates to a single patent (‘200) for a wide area packet telephony system. The Company and AT&T have been in discussions to resolve this matter for some time. Although the Company intends to continue to pursue an amicable resolution of this matter, the Company cannot assure that this matter will not ultimately be litigated
There is not a lot to go on yet but details should emerge about what this patent is soon enough.
