Abstract :
The flexibility of packet-switching technologies, coupled with the economic benefits of sending voice over IP networks, is accelerating the convergence of data and voice. It remains unclear, however, which voiceover-IP (VoIP) architecture will best meet user needs, which services will be most successful, and where in the network these services should reside. The question of where to place services in IP telephone networks depends on many variables, including the end systemsʹ capabilities, the amount of interaction the service requires with the end user, and the network infrastructureʹs architecture. The limited ability of dumb end devices, such as the telephones in the public switched telephone network (PSTN), force service providers to implement services within the network. Smart end systems allow providers more choice in where to locate services. This article describes the main architectural options for VOW and discusses their associated economic effects. By focusing on the relationship between architecture and market uncertainty, the author demonstrates how high uncertainty enhances the value of architectures that allow distributed network services.
