Metzler ended both days encouraging attendees to rethink their IT architectures to stress business value and take into account unknowns, such as the emergence of virtual data center technologies. The key, he said, is to be flexible enough to accommodate change.\nWe wrapped up the first two cities in the Network World Technology Tour on optimizing WAN services last week, which featured WAN expert Jim Metzler and speakers from seven sponsors: Adtran, Cisco, Equant, Expand Networks, Peribit Networks, Virtela Networks and Visual Networks.Metzler, a former network executive with two Fortune 500 companies and now an independent consultant, opened the events in New York and Chicago by noting the extremes of recent years - the "spend anything\/build everything" days pre-dot-bomb to defending our existence after Harvard Business Review published the "IT doesn't matter"story.That story was correct in saying some parts of our infrastructure have become utility-like, Metzler said. Look at our frame relay WANs and Ethernet LANs. But that's beside the point. IT does matter because, done right, it can give organizations six-, 12-, even 18-month advantages over competitors when it is applied to build business value.Metzler went on in his keynote address to focus on promising WAN technologies, including\u00a0VPNs, voice over IP (VoIP) and bandwidth optimization.Judging by a show of hands, a good percentage of the crowds in both cities use VPNs - say, two-thirds in New York and three-quarters in Chicago - but mostly to support remote access. Metzler and other speakers said there are bigger paybacks ahead in using VPNs in place of more expensive site-to-site frame relay and private lines.Fewer attendees use VoIP - about one-quarter in New York and half of the crowd in Chicago. Of those users, only a handful said they use it to support more than 25% of their voice traffic. That's not surprising, Metzler said, given research shows that half of organizations surveyed say their WANs are not ready to support the technology.But the VoIP mindset has changed in the last year, Metzler said. Twelve months ago people talked about using VoIP to save money on toll bypass, whereas today the conversation focuses on how the tech can ease the deployment of integrated applications.Regarding bandwidth optimization, Metzler said it is time to stop throwing bandwidth at problems. A whole host of technologies - from compression to caching and packet-shaping - are mature enough to warrant a close look. And in fact the audience heard from vendors who discussed advances in these areas.Metzler ended both days encouraging attendees to rethink their IT architectures to stress business value and take into account unknowns, such as the emergence of virtual data center technologies. The key, he said, is to be flexible enough to accommodate change.