XO Communications (previously Nextlink Communications, Concentric Network Corporation and Allegiance Telecom, Inc.) is a telecommunications company owned by XO Holdings, IncOTCBB: XOHO. XO provides managed services and converged Internet Protocol (IP) network services that combine voice, Internet access, and private data networking for small and medium sized companies, enterprises, national and government accounts. XO delivers services through a mix of fiber-based Ethernet and Ethernet over Copper (EoC). In addition, the company has external network-to-network interface (E-NNI) agreements with traditional carriers and cable companies.
XO sells its services through three channels: the direct sales channel, the indirect sales channel, and the wholesale division.