IP telephony was born nearly 10 years ago, when Cisco and 3Com purchased a few start-ups and launched a new enterprise voice market. It took about four years for companies such as Avaya, Nortel, Mitel, Alcatel, Siemens and NEC to feel threatened.Today, Avaya may be poised to break away from its competitors because of its focus on professional services and creating a developer's ecosystem around a new application development platform based upon Web services and service-oriented architecture (SOA). The next three years will be crucial as most enterprises choose an IP telephony vendor, locking in market share for years to come.Since 1996, IP telephony has transitioned through two phases and is now entering its third level of maturity. The first phase involved experimentation with VoIP and proprietary communication signaling built on a PC platform. This experimentation phase led to a stable and reliable IP telephony platform built upon a hardened Linux foundation. For some suppliers, IP telephony products now have the same reliability, availability and performance levels as traditional time division multiplexing telephony products.The current, second phase of IP telephony involves replacing legacy voice services with IP telephony for a favorable ROI. Today, IT management can deploy a new IP enterprise voice solution with 15% to 50% savings, depending on installed base. However, the current phase offers companies little of strategic value.The third phase of IP telephony is based upon a value proposition of strategic value vs. economic efficiency.Two new industry developments propelling this phase are Session Initiation Protocol (SIP) and Web services in an SOA construct. SIP standardizes call signaling and communications between different types of devices from different vendors. More importantly, SIP simplifies the writing of communication applications. The second development involves using Web services to write business applications that incorporate communications. SIP combined with Web services is enabling the business process to be linked with communications to deliver strategic value to users.As IP telephony transitions into the strategic-value stage over the next 18 to 24 months, the market may move into Avaya's value proposition of software and services. In contrast, all the other major IP telephony vendors are product focused, offering little to no professional services or application development environments. Many vendors base their application development around a relatively small number of highly specialized developers who can program with old protocols such as CTI, TAPI and JTAPI. As SIP and Web services take center stage, this developer community of thousands will explode to millions capable of injecting communications into business processes. Vendors that only offer IP telephony products may have enjoyed the appetizer but may miss out on the entree as the strategic-value phase takes hold.Lippis consults to CIOs of Global 2000 companies and their direct reports on network architecture development and its funding. He publishes the Lippis Report (www.lippis.com) and can be reached at firstname.lastname@example.org.