It seems that Vonage’s middle name is “lawsuit,” as the Voice-over-IP provider was once again sued in court over patent violation charges. This time it is the telecommunications giant Nortel Networks that filed a suit against Vonage, but despite this fact, the latter’s spokesman stated that he did not think the ongoing litigation would have any impact on his company’s business users.

The current lawsuit was filed in the U.S. District Court in Wilmington, Del., and it alleges that the defendant has violated no less than 12 of Nortel Networks’ patents relating to its Internet phone services, including click-to-call and the 911 and 411 services. Through this lawsuit, Nortel Networks is seeking damages, as well as an injunction on the use of the allegedly infringed technologies by Vonage. "From our perspective defending our intellectual properly rights is certainly a top priority for Nortel," said Nortel Networks’ spokesman, Mohammed Nakhooda.

Vonage would probably not have been involved in this legal feud, if it hadn’t acquired Digital Packet Licensing and three patents this company held. Related to those patents, Digital Packet Licensing filed a lawsuit in 2004 against Toronto-based Nortel Networks alleging patent infringement.

Nortel’s spokesman said that Vonage had had similar problems, but it continued to assert its claims against Nortel, by saying that it was in fact Nortel that was infringing on those patents. "This particular suit is a countersuit so the original lawsuit that alleged patent infringement was filed by Vonage. This is a defensive maneuver on the part of Nortel," said Vonage’s spokesman Charler Sahner.

Earlier this year, Vonage settled similar disputes with telecom companies such as AT&T, Verizon and Sprint Nextel.