Vonage Holdings acquired ownership of three patents from Digital Packet Licensing Inc. (DLP) that concern the compression of packetized digital signals commonly used in voice-over-Internet Protocol (VoIP) technology.

Vonage now gets to see through the litigation DLP began against Sprint Communications and Verizon Communications, charging infringement of one of the acquired patents. Vonage is already in cross-licensing negotiations with regard to them.

Other companies have already either settled with DLP, or have licensed the technology, including Motorola, Time Warner, and Qwest Communications. DLP last year sent a helpful letter to AT&T, bringing its patents to that company's attention that inspired some legal wrangling between the two.

Of course, turnabout is fair play, and Klausner Technologies Inc. filed suit against Vonage for infringing its patent number 5,572,576, which concerns the retrieval of VoIP voicemail on a cell phone or handheld device. Klausner is claiming damages and royalties estimated at $180 million. According to Klausner, Vonage failed to respond to a request that it license the VoIP voicemail patent.

Time Warner recently settled a suit with Klausner after the latter sued AOL for $200 million.

The three patents acquired by Vonage are U.S. Patent Nos. 4,782,485, 5,018,136 and 5,444,707. The company expects to continue to buy the rights to patents relevant to its business.