Verizon, after winning a patent-infringement decision against Vonage Holdings last year, has trained its legal guns on cable's phone services with a similar lawsuit against Cox Communications.
The telephone company's suit, filed Jan. 11 in the U.S. District Court for the Eastern District of Virginia, alleges Cox infringes eight patents related to delivering phone service over data communications networks. Verizon seeks unspecified monetary damages and wants Cox to be blocked from using the patents in the future.
The action comes after a federal appeals court affirmed Vonage infringed two of Verizon's patents. In October, Vonage said it would pay Verizon up to $120 million to settle the suit. Vonage also was the target of suits by AT&T and Sprint, both of which the Internet-phone provider also settled out of court.
The eight patents Verizon cited in the Cox suit include the two Vonage was found to have infringed: U.S. Patent No. 6,104,711, for an "Enhanced Internet domain name server" to translate information from a public, packet-based network; and 6,282,574, "Method, server and telecommunications system for name translation on a conditional basis and/or to a telephone number," which is an extension of the earlier patent.
Verizon's other claims against Cox concerned patents covering quality of service for a communications session, enhanced signaling, network session management, and inter-carrier signaling for connectivity between packet-based and circuit-switched networks.
Cox representatives did not immediately respond to requests for comment.
Apart from the Cox lawsuit, the phone company has not initiated patent-related litigation against another cable company. Verizon executive director of media relations David M. Fish declined to comment on why Verizon specifically chose to sue Cox.