In late September it was Cox Communications, and now in early December Centre One has filed suit against Charter Communications (8:19-cv-02317). The plaintiff asserts the same six patents, broadly directed to voice communications using an interface or gateway system between an IP network, such as a premise-based IP network, and a public switched telephone network (PSTN), with infringement allegations targeting voice over IP (VoIP) services that switch calls between PSTN and VoIP networks. AT&T is also in suit in this campaign, which began in 2008 but was revived in 2018.