XO Communications, LLC (previously Nextlink Communications, Concentric Network Corporation and Allegiance Telecom, Inc.) was an American telecommunications company. Before being purchased by and later absorbed by Verizon Communications. XO provided managed and converged Internet Protocol (IP) network services for small and medium-sized enterprises. XO delivered services through a mix of fiber-based Ethernet and Ethernet over Copper (EoC). In addition, the company had external network-to-network interface (E-NNI) agreements with traditional carriers and cable companies. Acquisition by Verizon Communications In a news release dated February 22, 2016, Verizon announced plans to acquire XO Communications' "fiber-optic network business." In 2017, Verizon completed its $1.8 billion acquisition of XO Communications. As of summer 2020 all XO services have been migrated to Verizon. References Companies based in Fairfax County, Virginia Telecommunications companies of the United States Transit-free networks Telecommunications companies established in 1996 American companies established in 1996 1996 establishments in Washington (state) Herndon, Virginia Verizon Communications acquisitions 2017 mergers and acquisitions