This work gives an over view of IP telephony and explain the existing difficulties in implementing VoIP services & migrate the TDM base telephony to IP telephony. When the architecture is deployed in IP based network. The causes of these problems are explained with three approaches used by carrier to solve interoperability. They are TDM base telephony to IP telephony by using soft switch and vo...

With the recent diffusion of broadband services, IP telephony is expected to spread significantly in Japan. This paper investigates the demand for IP telephony by using conjoint analysis. Projecting IP telephony demand also contributes to Japanese info-communication policy discussions. Two points are made. First, IP telephony is still currently considered an optional supplement or an add-on ser...

Convergence of data and telephony networks is one of the current trends in telecommunications. It is supposed that all telephony traffic might be carried over a common data network infrastructure in the future. In accordance with this development, wide area IP telephony network has been deployed in the TEN-155 CZ network (located in Czech Republic), connected to the European network for researc...

I nternet telephony, also known as voice over IP, may finally be ready for prime time in 2004. An increasing number of IP telephony providers , traditional phone carriers, and now cable companies—includingage—are offering a growing range of corporate and residential services nationwide. Internet telephony is attractive to customers because it uses lower-cost equipment and is less expensive to o...

In Japan, demands for broadband Internet access and IP telephony have increased dramatically in recent years. According to official sources, as of September 2009, there are 30.9 million users of broadband Internet access and 20.9 million of IP telephony. This study evaluates and estimates the market share of fiber-optic Internet connection, which is becoming the major player in broadband servic...