Overview

The evolution from a circuit switched to packet switched communications system platform has been one of the most widely discussed and analyzed events within the enterprise communications system market for the past few years. Globally, customers have invested more than one quarter trillion dollars in currently installed circuit switched premises communications system hardware, and migrating to the new packet switched technology platform will be a slow and gradual process because investment protection is a very important buying decision criteria. Customers are beginning to realize that enterprise communications systems based on an IP control signaling and communications transmission platform are not a new product type but merely another category of PBX systems. A customer s enterprise communications system will continue to be referred to as a PBX system, regardless of the underlying technology used to support real-time communications between station users. The emergence of IP packet switched communications technology is not the first time a major technology disruption in the PBX status quo has occurred.

Analog PBXs transformed into digital PBXs during the late 1970s and early 1980s, just as circuit switched digital PBXs are currently transforming into packet switched PBXs, but remnants of the older technology will not immediately disappear. When Rolm, a pioneering interconnect equipment supplier since acquired by Siemens, introduced the first PBX system based on a digital circuit switching platform in 1975, it was not the beginning of the end of the sale and use of analog telephone instruments. Rolm s digital circuit switched Computerized Branch Exchange (CBX)...