"Things are really hopping, and a lot of technologies such as Wi-Fi and VOIP are maturing, so we're seeing that hockey-stick-shaped growth," Lenny Heymann, general manager of Interop, said in an interview last week.

About 18,000 people are expected to attend, up from 17,000 last year, with about 375 exhibitors, up from 350 last year, Heymann said. With the demise of the gargantuan Comdex show, Interop is now the biggest IT show in North America.

Interest in Interop is keen among both IT managers and buyers, said analysts such as Zeus Kerravala at Yankee Group Research Inc. "For the first time in a long time, it's kind of cool to be in networking again," he said. "In recent years, the focus was on cost containment. But now IT managers are focusing on growth again, looking at network and communications systems."

This will the 21st year for Interop, which in 2005 dropped the name Networld+Interop and added a New York version of the show. That Interop took place in December.

This week's Interop offers a broader range of vendors, including more content in the areas of open-source, storage and application networking, as well as expanded education sessions. That comes in addition to show's more conventional technology areas, including voice over IP (VoIP), wireless, network security, data center and services, said Interop spokesman Ben Stricker.