From POTS to PANS: a commentary on the evolution to Internet telephony

We describe some of the challenges and problems as we move from the world of plain old telephony services (POTS) to the promise of Internet-based pretty amazing new services (PANS). We present a set of ideas that relate the architectural evolution of networks and services to the underlying changes in technology. After examining the motivations behind the drive to Internet multimedia communications, we discuss the distribution of service intelligence in the future communications architecture. As with any period of evolution, thorny problems arise regarding interworking between the two network architectures. An exploration of the intelligent network is presented as a solution to address interworking. Finally, we examine how the transition to on Internet-based system might affect billing for transport and services.