The challenges of IP telephony - from making the business case for convergence to the down-and-dirty of power supplies in telecom closets - generated plenty of spirited discussion at last week's VoiceCon show.ORLANDO - The challenges of IP telephony - from making the business case for convergence to the down-and-dirty of power supplies in telecom closets - generated plenty of spirited discussion at last week's VoiceCon show (complete VoiceCon coverage).More than 5,000 IT professionals, consultants and vendor representatives crowded the Gaylord Palms Convention Center to get their hands on the latest IP telephony gear, discuss convergence strategies and debate the direction of key technologies such as Session Initiation Protocol, unified messaging and VoIP services."Is there a killer app for IP telephony? I don't think so," said Jamie Libow, telecommunications manager at St. Paul Travelers. "But in buying into IP telephony, you're enabling lots of what I call mini-killers."St. Paul Travelers uses a mix of Avaya and Cisco IP telephony gear that gives employees who move between offices in Minnesota and Hartford, Conn., more flexibility. For example, they can keep the same phone extension at both locations. Libow can bring up field offices in days instead of weeks by tying small-office gateways into the main PBX over IP. Also, his new disaster recovery scenarios - where all calls are shifted over an IP network from Hartford to a Georgia-based data center - would not have been possible with traditional TDM switching, he said. In a recent move to a new building in Hartford, substantial cost savings were realized by running single Ethernet cables - carrying IP voice and data wires - to hundreds of desktops, instead of two separate cables. All these factors add up, Libow said.A good convergence strategy involves finding IP voice applications that will save money or increase productivity, and reorganizing an IT staff to handle the changes that convergence brings, said David Stever, manager of communication technology services at PPL Corp., an energy company with a mixed IP and TDM network from Nortel. (His firm won Network World's 2005 Renovator Award for best network upgrade.)"You won't get the best benefits out of infrastructure convergence if you don't converge" your telecom and datacom departments, Stever said. "You want to make sure that management, all the way up to CIOs and above, really buys into [IP telephony]." IT professionals must show that IP technology by itself cannot be implemented under old telecom and datacom organizational structures. "Link it all together and make it clear that the organization is a critical piece," he said.While it is important to convince management to reorganize data and voice groups, don't forget to rally the telecom troops as well, says one IT professional."You have to get [the telecom staff] excited" about making a switch to IP telephony says Bruce Mellott, senior communications engineer at Disney Worldwide Services. "You have to let them know that the days of punch-down and running cable and crimping RJ-11 jacks is prety much going away, and that if they want to advance forward . . . they have to get excited about learning new things. Those that don't want to learn anything new will have to go by the wayside."Getting to the point where IP telephony's benefits are realized can be hard, as IT professionals from two large entertainment companies described. Powering IP phones in large deployments is an obstacle for both.At Viacom\/MTV Networks, which is installing thousands of IP phones in its New York offices, "the building's capability to provide us with enough power to support redundancy" is the challenge, said Eileen Wainwright, the company's senior director of telecommunications infrastructure and operations. "We have over 300 users per floor. . . . We're really struggling, especially in Manhattan, getting power up to the 33rd floor or the 55th floor of a building."Disney Worldwide Services, which manages IT and telecom for the entertainment company, has large-scale IP telephony sites in Japan and on both U.S. coasts. Bruce Mellott, senior communications engineer for the company, also sees power and cooling issues when digital phones are replaced with IP sets - the equivalent of putting another, smaller computer on desktops."There are a lot of challenges inside the wiring closets in terms of battery consumption," he said. Providing redundant power to IP phones - which are powered by Power over Ethernet (PoE) LAN switches - requires battery backups in the wiring closets and PoE gear that draws more power and produces more heat than previous switching equipment. Most data closets are designed for 120-watt outlets, Mellot said, but some gear can require more."That has been one of our biggest challenges; how to do this with our existing infrastructure," he said. "We spent 20 years really working hard to separate voice and data . . . and I said to my boss, we did a good job, because we don't even have a single [conduit] running through the [datacom and telecom] closets."Besides selling the VoIP business case to management and dealing with the technical details of a VoIP rollout, users at VoiceCon were faced with hundreds of vendors pushing new enterprise VoIP products and services."Right when you think you're on the cutting edge, you're not," said Peter Tseronis, director of network services for the U.S. Dept of Education, which ties together eight buildings in Washington with VoIP. "I just put in a requisition for a product that I wanted to buy the other day, and now I have to think about taking that off the table," after seeing some of the wares at VoiceCon.