Unlike the PSTN, which was originally created as a single, proprietary network with closed architectures and protocols, the emerging IP telephony network will mature in a deregulated, fast-paced environment. The central office (CO) will be augmented by the distributed intelligent office, which places the functionality of CO switches on standard commercial platforms networked together using open interfaces and standard protocols. This approach will enable innovators to add to the capabilities of the network or to specialize in specific functions.

The applications and services delivered by IP-based networks will surpass what the PSTN can do, realizing the promise of unified messaging, information services, and advanced multimedia applications such as multimedia conferencing. Applications such as virtual and networked call centers, auto-provisioning, unified messaging, virtual office, online directory, and more, will likely employ a variety of different media and application servers such as voice XML (VXML), content, and hosting servers. Above all, IP services will enhance the advantages of a single, converged network to advance municipal efficiency. The benefits derived from these applications will be greater than most municipalities realize.

It’s interesting to note that Microsoft ( announced February, 2003 ) has committed to a product strategy that offers integrated voice and other converged communications services built into Windows XP, Windows CE, .Net devices and, coming soon, into Windows 2003 (NT-based) operating systems. While we’ve seen phone system suppliers developing converged voice and data applications for several years now, the possibilities get even more exciting when the reverse is also true. Microsoft is offering full support of Session Initiation Protocol and XML, both of which enable third-party development of interfaces and applications and has even published its XML extensions to ease development of further applications. They have already demonstrated interoperability with systems supplied by traditional telco-centric companies like Siemens and Nortel. Telecom will become more “server-centric” and “IP-centric” as opposed to circuit-switched PBX systems.