http://www.networkworld.com/news/2010/020610-patent-office-to-review-voip.html?source=NWWNLE_nlt_daily_am_2010-02-08In 2006, C2 sued all the major U.S. carriers, including AT&T, Verizon and Qwest, alleging they were infringing the patent. All the carriers settled out of court with one-time payments, according to Weintraub. C2 believes many more companies are violating the patent, as well as another VoIP-related patent owned by C2. Its patents cover most of the technology used in VoIP, though not all VoIP products may infringe them, he said.
That's dirtier than AT&T itself
