XO Communications is one of the nation’s largest communications service providers focused exclusively on businesses, government, and carrier and wholesale service providers nationwide.

We serve customers through two primary business units:

• XO® Business Services 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® Carrier Services delivers high bandwidth IP and inter-city network transport services for domestic and international carriers, service providers, cable companies and mobile wireless operators.

Concentric® offers a range of Software-as a- Service applications to help small and medium businesses manage and grow their business. These services include hosted email and messaging, managed server, web site and applications hosting, domain management, and professional services related to these services.