Interop Las Vegas 2006 kicks off bigger and broader this week, with promoters touting it as the biggest IT show in North America in the era following the dot-com bust."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. "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 last 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 VoIP, wireless, network security, data center and services, said Interop spokesman Ben Stricker.While much of the focus will be on new products, broad themes and networking trends will be discussed in keynotes, which include presentations by executives from IBM's storage systems group and Google. Google also sent a representative to the New York Interop -- a development that caught the attention of many networking experts."Google's presence at Interop is interesting," Kerravala said. "Nowadays all the carriers are becoming IP-based, which means you remove the need to have a service tied to a network, so it's not out of the realm of possibility that Google could become a large provider of enterprise voice in five years or more."At Interop, Siemens Communications, a division of Siemens AG, will announce the results of a two-year effort to use service-oriented architecture (SOA) standards and Web services interfaces for its communications applications, said Scott Washburn, global portfolio manager at Siemens. The vendor recently announced that its communications SOA is compatible with IBM's WebSphere and Service Delivery Platform and SAP's NetWeaver. The company also struck a marketing alliance with Microsoft in the area of business collaboration systems.Later this year, Siemens will announce next-generation products that are SOA-based, including its HiPath 8000 high-end IP voice switch, Washburn said.