Verizon, Vonage Trade Barbs in Court

In the opening salvos of the patent infringement case between Vonage and Verizon, the telecommunications company claimed Vonage caused serious harm, while the VoIP provider said it had no knowledge of Verizon's patents.

Already in its fourth day, the trial is now centering on arguments over Verizon's claimed losses and whether or not Vonage did indeed willingly infringe on the telco giant's patents. If found guilty, Vonage could be liable for as much as $200 million, say experts called to testify.

Vonage is defending itself by claiming that it did not know of Verizon's patents when it first started developing its services. Additionally, the company was never approached about possible patent infringement until June 2006, when Verizon originally filed suit.

It also said in cross-examination by Verizon lawyers that it felt that checking to see if anyone held patents on the technology it was developing was unnecessary since it was using publicly available information.

Lawyers for Vonage were successful in getting Verizon Chief Marketing Officer Bob Ingalls to admit that a majority of Verizon customers opt for cable services over Vonage, possibly damaging the telco's argument that the company is chiefly responsible for its VoIP woes.

Studies show that cable service registrations by former Verizon customers outpaced Vonage by over a six to one margin.

Vonage calls the lawsuit "frivolous" and said in a statement on Monday that it expected the court to see Verizon's case "exposed as a transparent attempt to stifle one of its most successful competitors."

Verizon has its own VoIP service, known as VoiceWing. The company launched the offering in 2004, although it has seen slow adoption.

Details of the deliberations were reported by Reuters and CNET Wednesday.