Our research has shown that most mid-sized to large enterprises are either currently using IP telephony or currently investigating whether to deploy IP telephony into their networks. Enterprises are also investigating what is required to deliver quality video over the LAN and WAN. We expect that by 2005, 60 percent of new phone systems sold will be either IP PBXs or hybrid IP PBXs. The biggest challenge for enterprises that are currently investigating whether to purchase VoIP systems for their network is to understand the issues, best-practice procedures, and costs in preparing the network to deliver quality voice. Because voice and video are real-time applications that are affected by delay, jitter, and packet loss, it is not a given that quality voice or video can be delivered over a data network without several steps being taken by the enterprise and the integrator. Network issues surrounding convergence are difficult for buyers to understand because the costs and requirements to set up the network for voice and video vary depending upon the current organization's infrastructure equipment and current application environment. The technology is still new, which means that the vendors themselves are still learning what is required to deliver quality voice and video over a data network. A mistake-either choosing a system integrator that doesn't understand best practice procedures for convergence, or having the wrong network equipment in place-will lead to poor voice or video quality, which is unacceptable for enterprise users. Our research has shown that enterprises can get PSTN-quality voice and video, however, if the right equipment is in place, and the required audit, design, and implementation work is done by experienced integrators. Adoption of voice-over-IP equipment is beginning to gain traction in the United States. The Yankee Group estimates that 10 percent of new system sales for phone systems were either IP PBXs or hybrid IP PBXs in 2001. A signifcant portion of enterpises that use video conferencing are today using the company WAN for intra-company video communications. The total cost of ownership (TCO) advantages that both VoIP equipment and video-over-IP equipment have over circuit-switched equipment are clear to the Yankee Group, most of the vendors and integrators of enterprise equipment, and a significant portion of enterprises. The wild card, however, is in trying to figure out how much the intial up-front costs and work associated with preparing the data network for convergence could potentially offset TCO advantages of VoIP and video equipment. It is also clear that the audit, design, and implementation work associated with VoIP or video equipment is a lengthy and arduous process-an art, not a science, today. Vendors and integrators have put best practices in place, but because the technology is new, the Yankee Group recommends that the buyer pay close attention to the number of installations the integrator has under its belt and the market leadership position of the vendor. Our research tells us that the percentage of both voice and video equipment technicians that are trained and experienced enough to handle VoIP or video-over-IP installations is still low. As mentioned, our studies have shown that TDM voice quality can be reached with the proper network preparation work and the correct network equipment in place. Voice and video quality and relability will also be influenced by an IP telephony or video-over-IP platform. ConclusionBusiness users of voice equipment will not accept any less quality or reliability with IP PBXs than what they have come to expect from circuit-switched PBXs. Voice quality-without delay, jitter, or packet loss-is not a given when delivered over a packet network. Until VoIP and video-over-IP quality becomes less of a variable, adoption will be hindered and costs for preparing the network will be high. Both vendors and systems integrators, however, are making great strides toward learning the procedures to deliver quality voice and video. We recommend that most enterprises strongly consider purchasing an IP telephony system when it is time to look at a new phone system. The only exception to our recommendation would be for an enterprise that has an old data infrastructure and does not have the budget to upgrade the data network. But because of the aforementioned realities, however, we are recommending that the following actions be taken by enterprises before they install an IP telephony system into their network:Attempt to obtain data from the vendor that validates the vendor's market position for IP telephony systems. The platforms delivered by the vendors are varied in terms of reliability and product maturity. It is not enough to go by old market share leadership perceptions for phone systems. Some of the legacy vendors have been slow to develop and push IP telephony, and as a result are behind some of the newer vendors in this market.Invest the time to understand your own network, and the underlying infrastructure and applications. The more information that you have, the less you will have to pay for the audit. Most vendors are using an indirect distribution model. As a result, it is just as important, if not more important, to choose the right integrator as it is to choose the right vendor. There is no better way to learn what is involved in preparing the data network for voice or video than getting sales and putting systems in. This is why we are strongly recommending that enterprises use the integrator with the most proven IP telephony experience.