Comtech EF Data Corp., a subsidiary of Comtech Communications, has filed suit against Scientific Telecommunications LLC (SciTel) seeking declaratory judgments of non-infringement of the four patents (6,519,259, 6,058,429; 6,546,424; 7,222,188) that the NPE has affirmatively asserted against other companies (2:16-cv-03105). The ‘259 patent generally relates to improving packet-based voice communications; the remaining three patents generally concern packet switching between virtual local area networks without necessitating a routing protocol. Comtech’s complaint contends that licensing talks that began between the parties in September 2015 broke down, but it notes that a non-disclosure agreement prevents the public disclosure of further details.