Act IV: Nortel drags Vonage back to court

The networking company says that Vonage is violating nine of its patents, including those related to emergency and information calls, as well as click-to-call functionality.

Just when it seemed Vonage might be able to spend the winter out of court, it finds itself dragged back in. Nortel filed suit against the VoIP provider last Friday in US District Court for the State of Delaware, seeking an injunction against it to prevent further use of what Nortel claims to be its technologies.

Nortel's move is in response to a suit by the VoIP provider that claims it violated three patents it holds. Vonage acquired the patents from Digital Packet Licensing in July 2006, which may have had a pending case against Nortel since 2004.

You'd think it would be easy enough to say whether or not someone had already sued someone else. But this February 2006 letter from DPL to Nortel was apparently an unusual way of saying it wasn't really suing Nortel at all...just moving it in the general direction of a courtroom.

Vonage decided to continue the non-lawsuit lawsuit after the acquisition. It marks a rare point in the VoIP provider's recent history where it was the one suing rather than the one getting sued.

Litigation in that suit is ongoing, but Vonage said it was not against settling out of court. Like many patent fights, it appears Nortel sued the VoIP provider more out of an attempt to force Vonage's hand at the bargaining table.

Nortel's suit "is a countersuit in defense," its spokesperson said -- a way of saying we wouldn't be suing you unless you were suing us.