THEN: In 1987, Carl Grivner was vice president of national sales at Ameritech, which was one of the newly created seven Baby Bell companies. It operated in five states of Ohio, Illinois, Wisconsin, Michigan and Indiana.

NOW: He is CEO of XO Communications, the country’s largest CLEC operating in 75 markets nationwide. XO has 4,800 employees and nearly $1.5 billion in annual revenue.

“The biggest changes have come as a result of the explosion of wireless and the advent of the Internet and IP-based communications,” he says. “These two forces, which didn’t exist 20 years ago, are allowing people to communicate and conduct commerce from anywhere.”