Internet phone company Vonage Holdings Corp. sued a U.S. unit of Canadian telecommunications equipment maker Nortel Networks Corp., seeking to invalidate three patents for managing telephone data.
Nortel is attempting to sue Vonage in Texas for infringing the patents. Vonage contends that those patents are not valid.
In March, a federal jury decided that Vonage infringed three patents owned by Verizon Communications and awarded $58 million. Vonage said it might be forced into bankruptcy by the verdict and is appealing.