By Joseph Marks

Law360, New York (January 12, 2011, 4:31 PM ET) -- VirnetX Inc. on Wednesday accused Siemens AG and Mitel Networks Corp. of violating two telecommunications patents, including one that netted the plaintiff more than $300 million in payouts from Microsoft Corp.

Siemens and Mitel violated U.S. Patent Numbers 6,502,135, titled “Agile Network Protocol for Secure Communications with Assured System Availability,” and 7,418,504, titled “Agile Network Protocol for Secure Communications Using Secure Domain Names,” according to a complaint filed in the U.S. District Court for the Eastern District of Texas.

VirnetX claimed Mitel’s SIP-enabled phones, which allow...