John Dumbleton

ClearSpan LLC powers unified communications solutions for large organizations and service providers. The company is based in Plano, TX and was founded in 1978. The company's standards-based architecture delivers carrier-grade reliability, scalability, and security while allowing for seamless integration of modern and legacy business applications. The CEO is Bill Crank.

McLeodUSA, Inc. provides telecommunications services. The firm provides integrated communications services, including local, long distance, data, and Internet service in 25 Midwest, Southwest, Northwest, and Rocky Mountain states in the US. The company was founded in 1992 and is headquartered in Cedar Rapids, IA.

MCI, Inc. provides telecommunication services. It serves thousands of businesses and government entities throughout the world and provides voice, data and Internet communication services for millions of customers. The company is located in Ashburn, VA

Allegiance Telecom are a facilities-based national local exchange carrier that provides integrated telecommunications services to business, government and other institutional users in major metropolitan areas across the United States. We offer ‘‘one-stop shopping’’ for voice, data, and integrated communications services (including local, long distance, Internet, data colocation, web hosting and customer premises equipment sales and maintenance services), with convenient, integrated online billing, plus a single point of contact for sales and service. Our principal competitors are incumbent local exchange carriers (also known in the industry as ‘‘ILECs’’), as well as, long distance carriers, other integrated communications providers, and customer premises sales and maintenance business.

Masergy Communications, Inc. operates as software defined networking services company. Its solutions include unified communications, managed sd-wan and security. The company was founded by Barry D. Nalls in 2001 and is headquartered in Plano, TX.