Carl J. Grivner

Chief Executive Officer

Carl Grivner was appointed chief executive officer of XO Communications on May 15, 2003.

Mr. Grivner's career in telecommunications and technology spans more than 25 years. Formerly, Mr. Grivner was chief operating officer at Global Crossing, a position he held from February 2002 until April 2003. Mr. Grivner joined Global Crossing in June 2000 as executive vice president of global operations. Prior to joining Global Crossing, Mr. Grivner was chief executive officer of Worldport Communications. He is also a former chief executive officer for the Western Hemisphere at Cable & Wireless. Additionally, Mr. Grivner has held various senior executive positions at Advanced Fiber Communications. Early in his career he held various positions with Ameritech and IBM.

Mr. Grivner received a Bachelor of Arts from Lycoming College and served in the United States Marine Corps from 1975-1978.

He is a board member and vice chairman of CompTel, the nation's largest association of facilities-based competitive telecommunications companies.

Wayne Rehberger

Chief Operating Officer

Wayne Rehberger is chief operating officer of XO Communications. In this role he is responsible for all aspects of XO's operations including marketing, network and sales. He previously served as the company's chief financial officer for more than three years. During that time he led the company through a successful financial and operational restructuring that improved XO's operating metrics and financial performance through efficiency initiatives and the reduction of operating and overhead costs.

Mr. Rehberger has 20 years of diversified telecommunications management experience including having served in a number of executive roles at MCI Communications Corporation. During his time at MCI, Mr. Rehberger served in a variety of corporate and business unit accounting, finance, and operational support roles. He was involved in major acquisition activities, both from a business development and operational integration role. Mr. Rehberger held the position of senior vice president of Finance at MCI WorldCom prior to joining XO.

Prior to joining MCI, Mr. Rehberger served four years in the U.S. Army, achieving the rank of captain before joining KPMG's consulting practice in Washington, D.C. where he worked on various management consulting engagements focused on business strategy, marketing, and program/product management.

Gregory W. Freiberg

Chief Financial Officer

Greg Freiberg is senior vice president and chief financial officer of XO Holdings, Inc. and XO Communications, LLC. Prior to being named chief financial officer in April 2006, he served as XO's vice president of finance and controller.

Freiberg joined XO from Asia Netcom where he was senior vice president of finance. Prior to the acquisition of Asia Global Crossing by China Netcom, Freiberg held the same position at Asia Global Crossing. During this time he also served on the Board of Directors for joint ventures with Hutchison in Hong Kong, Dacom in Korea, Digitel in the Philippines, Starhub in Singapore, and Marubeni in Japan.

Prior to joining Asia Global Crossing, Freiberg was senior vice president and chief financial officer for all lines of business at Level 3 Communications. Prior to Level 3, Freiberg was the founding chief financial officer for MCI-WorldCom in Asia Pacific where he oversaw the growth of the business from a start-up to a triple-digit growth company operating in 12 countries across the Asia Pacific region.

Freiberg received his Bachelor of Science in Accounting from the University of South Dakota and served in the United States Army National Guard from 1986-1995.

Heather Burnett Gold

Senior Vice President, External Affairs

Heather Burnett Gold is Senior Vice President of External Affairs at XO Communications. In this role she oversees all of XO's advocacy with the federal government, including Congress, the FCC, other federal agencies, and the White House, and with state legislative and regulatory entities.

A telecommunications veteran with more than 20 years of experience, Gold joined XO from the KDW Group, where she was a co-founder & principal, providing strategic and financial planning to companies in the telecommunications industry with respect to opportunities created by regulatory change. Prior to The KDW Group, Gold was vice president of industry affairs at Intermedia Communications where she oversaw the company's regulatory, legislative and industry relations at both the state and federal levels. Before Intermedia, Gold served as president of the Association for Local Telecommunications Services (ALTS) from 1993 to 1998. During her tenure at ALTS, Gold was a leading proponent for opening local telecommunications markets to facilities-based competition and a driving force behind the Telecommunications Act of 1996. Before joining ALTS, she served as vice president of member services for the Competitive Telecommunications Association (CompTel).

Gold holds an MBA in marketing and finance from Washington University in St. Louis and Bachelors and Masters degrees in Economics from Tufts University.

Simone Wu

Senior Vice President and General Counsel

Simone Wu is senior vice president and general counsel of XO Holdings. In this role, she oversees the company's legal affairs, which include commercial, corporate, employment, and intellectual property matters, as well as all litigation in which the company is involved.

Wu has almost 20 years of wide-ranging experience in the telecommunications industry, including domestic and international business and corporate development, intellectual property and commercial matters, and legal and regulatory affairs. Prior to joining XO in 2001, Wu held business and legal positions at MCI and AOL among other places, and practiced domestic and international transactional and communications law at the law firm of Skadden, Arps, Slate, Meagher & Flom. She is a member of the board of directors of the Minority Corporate Counsel Association.

She graduated with high honors from the University of Michigan with a degree in Political Science and as a Harlan Fiske Stone Scholar from the Columbia University School of Law.

Terri Burke

Vice President, Human Resources

Terri Burke joined XO in April 2000 and was named Vice President, Human Resources in 2001. She is responsible for all of the XO Human Resources and Training Functions.

Burke brings over 20 years of diversified telecommunications management experience to XO including having served in a number of executive Human Resources roles at MCI Communications Corporation/MCI WorldCom prior to joining XO. Prior to MCI, she was at Satellite Business Systems, a subsidiary of IBM.

She holds a Bachelor of Arts in Business Administration and Economics from Bridgewater College.

Robert Geller

Chief Information Officer

Robert Geller is XO Communications' Chief Information Officer. He is responsible for overseeing all the company's IT operations.

Since joining XO in 2001, Geller has significantly improved the quality, timeliness and cost management of IT operations. Additionally, he has overseen the development of several architecture plans, including those that directly impact the ability of XO to provide superior service and delivery to customers.

Prior to joining XO, Geller served as the Senior Vice President of Information Technology at US West/Qwest where he played a pivotal role in raising delivery standards and producing key systems for long distance, DSL, wireless, and e-business for all of the company's business units.

Prior to US West/Qwest, Geller was the Vice President of Software Development for MCI where he held a variety of senior executive positions.

Ernie Ortega

President, XO Carrier Services

Mr. Ortega is president of XO Carrier Services. In this role, he is responsible for marketing, operations, sales and service delivery of wholesale voice, data and Internet services to emerging and established telecommunications companies, cable companies, content providers, Internet service providers and wireless operators.

Mr. Ortega has spent more than 20 years in the telecommunications industry. Prior to his current role, Mr. Ortega was president of carrier sales for XO Communications. Before that, he was vice president of national accounts, responsible for developing and overseeing sales and services to enterprise and wholesale accounts. Prior to joining XO, Mr. Ortega held several sales management positions at MCI in its southwestern U.S. division.

Tom Cady

President, XO Business Services

As President of XO Business Services, Tom Cady oversees the sales, marketing and delivery of voice, data and IP communications services to all XO business customers, from small and medium businesses to large enterprises. In this capacity, Mr. Cady manages more than 1,000 finance, marketing, sales and service delivery employees nationwide who interact daily with XO business customers.

Mr. Cady has more than 25 years of experience in the technology and telecommunications industries. Prior to his current role, he led development of Nextlink, the broadband wireless subsidiary of XO Holdings, XO Communications' parent company, until Nextlink's launch in April 2006. He also previously served as XO Communications' chief marketing officer in which he was responsible for the direction and execution of all aspects of the company's product marketing, product and channel management, and customer communication efforts.

Prior to joining XO, Mr. Cady was president and CEO of SOTAS, a provider of business analytic software for communication service providers. Prior to this role, he was president and chief operating offier and co-founder of BroadStreet Communications, a provider of broadband communication services. Before founding BroadStreet, he was the senior vice president of marketing for Adelphia Communications.

Cady began his career with a variety of marketing and sales roles at Xerox and IBM. He holds a Bachelor of Science in Business Administration from Virginia Tech and an MBA from the University of Richmond.

Randy Nicklas

Chief Technology Office

As Chief Technology Officer for XO Communications, Randy Nicklas is responsible for the overall network technology vision for the company’s voice, data, and transport networks. He also advises on the overall design of XO’s commercial and wholesale voice, data and IP-based services.

Previously, Randy was vice president of Engineering, responsible for the design, implementation, and sustaining engineering of XO’s transport, voice and data networks. Before joining XO, he held engineering and technical management positions at Intelsat, Cisco, and MCI. Randy has also worked in the areas of software development and systems engineering on a variety of aerospace programs for NASA, Los Alamos National Laboratory, and Computer Sciences Corporation.

He obtained a B.S. and M.S. in Applied Mathematics and an M.S. in Physics, all from the Georgia Institute of Technology.

Steve Nocella

Senior Vice President, Network Services

As senior vice president of network services, Steve Nocella leads XO Communications’ 900-person strong network services organization. In this role, he oversees all aspects of network operations, network planning, network engineering, process development and service assurance.

Prior to assuming this role, Nocella had been vice president of network operations, and before that had been vice president of network engineering. In those positions he was responsible for network operations, service delivery, and planning as well as the deployment of network technology. Prior to these roles, he was director of network engineering, managing the company’s switching, transport and access networks in the northeast region.

Nocella began his career with AT&T Local Services where he held a number of positions in planning, operations, and engineering.

Nocella holds a Bachelor of Science in Electrical Engineering from Rutgers University and an M.B.A. from Columbia University.

Craig Collins

President, XO Small Business Services & Hosting

Craig Collins is president of XO Small Business Services and Hosting (Concentric) for XO Communications. Mr. Collins is focused on building and delivering end-to-end communications solutions for small businesses.

Prior to his current role, he served as vice president and general manager of sales and business development at Nextlink Wireless, a leading provider of broadband wireless solutions for the carrier, business and government markets. At Nextlink, Collins developed a sales organization which consisted of direct, indirect and government channels as well as sales operations. In this role he established the company’s first service agreements with some of the industry’s largest mobile telephone companies.

Before joining Nextlink Wireless, Mr. Collins was vice president of product management at XO Communications, overseeing the company’s entire business services portfolio. During his tenure he rationalized the company’s product portfolio following the acquisition of Allegiance Telecom and oversaw the launch of the first bundled VoIP solution. Prior to that, Mr. Collins held roles overseeing XO Communications’ web hosting business and XO Interactive.

Prior to joining XO Communications, Mr. Collins was vice president of Intermedia Business Internet, a fully owned subsidiary of Intermedia Communications Inc. Before Intermedia, he was director of enterprise marketing for Bell Atlantic Corporation. Prior to joining Bell Atlantic, Mr. Collins was at AT&T where he held multiple sales and product management positions.

Mr. Collins played college basketball at Penn State University where he was the captain and most valuable player in his senior year. He also held the NCAA Basketball Division I free throw record for 20 years with a free throw percentage of 95.9.

Mr. Collins holds a B.S. in Hotel, Restaurant and Institutional Management from Pennsylvania State University, and an M.B.A. from Georgetown University.