Defendant
1 case as defendant.
Metaswitch, Inc. (operating as Metaswitch Networks; formerly Data Connection Ltd., renamed Metaswitch Networks Ltd. in 2011) is a UK-headquartered telecommunications software company founded in 1981 in Enfield, England by seven former IBM employees led by Ian Ferguson. Its US arm is Metaswitch Networks Corp. Ownership has changed repeatedly: it was private and PE-backed by Francisco Partners and Sequoia Capital (from 2008), acquired by Microsoft in July 2020, then sold to Alianza, Inc. in a deal completed March 4, 2025; Microsoft retained the packet-core assets. Headcount has been reported in the 700–800 range (PitchBook, Wikipedia); the company does not disclose revenue and no verified figure was found, so one is not stated here.
Products / operations. Metaswitch develops carrier-grade, cloud-native communications software for service providers, equipment manufacturers and large enterprises. Main lines include voice softswitches and media gateways, session border controllers, application/feature servers and unified-communications/PBX platforms, plus portable network protocol stacks (SIP, IP routing, MPLS, ATM, legacy SNA/mainframe connectivity) licensed to equipment vendors. It also provided virtualized 5G/LTE network functions and network-slicing software. It is an operating company, not a shell or assertion entity, with roughly 200+ patent filings. Project Calico was spun out of the company as Tigera.
Patent-litigation posture. The tracked data shows 1 case, 0 as plaintiff and 1 as defendant — consistent with an operating company being sued rather than an NPE. In practice Metaswitch was an active two-way litigant: it counterclaimed on its own patents in the Sonus suits and filed several IPRs (e.g., IPR2019-00051, IPR2019-00396) against Sonus/Ribbon patents. The tracked case sits in the plaintiff-friendly Eastern District of Texas, Marshall Division.
Notable case. Sonus Networks, Inc. v. Metaswitch Networks Ltd. et al. (E.D. Tex., Marshall Div., 2018) was one of six related suits between the parties over VoIP/softswitch and gateway technology. In April 2019 the parties settled; Metaswitch agreed to pay Ribbon (Sonus's successor) $63 million and to globally cross-license patents. Metaswitch separately filed an antitrust complaint against Ribbon in the S.D.N.Y. in November 2018.
Sonus Networks sued Metaswitch entities in the Eastern District of Texas, asserting the '971 Patent among other patents. The case was settled and dismissed with prejudice on July 1, 2019. The narrative notes conflicting filing dates (March 8, 2018 per SEC disclosure; April 18, 2018 per docket summary).