TABLE OF CONTENTS One objection many service providers have regarding Voice over IP (VoIP) and softswitch technologies is the perception that they do not duplicate the 3,500 features of a Class 5 switch. The first question many would have is, what are those features by name and what functions do they perform? A consensus in the industry is that a residential customer may use a maximum of four or five features. A business customer may use upwards of a dozen features. Centrex 21 offers 21 of the most often used features. Private branch exchanges (PBXs) do not offer 3,500 features, as no such demand exists in the enterprise market. Subscribers access those features via their dual-tone multifrequency (DTMF) dial pads on their telephone handsets. Although in U.S. markets some regulatory agencies may require some features beyond Centrex 21, E911, and the Communications Assistance for Law Enforcement Act (CALEA), the race by Class 5 vendors to offer more and more features can be described in terms of Christensen's Innovator's Dilemma as "technology over abundance."
Softswitches that replace a Class 4 switch, for example, transmit features over the Internet Protocol (IP) network. Softswitches that replace a Class 5 switch utilize application and media servers that replicate the features found on a Class 5 switch. They potentially offer features not found on a Class 5 or not even possible with a Class 5 switch. These features are usually written in text-based languages using open standards. It is possible that, given...
