Voice over IP (VoIP) is rapidly changing the way we use the telephone for voice communications. The term "Voice over IP" defines the transport of VoIP‐based networks, including the signaling and streaming protocols as well as describing the codecs. VoIP is widely used by all kinds of consumers ranging from computer enthusiasts who are excited to get free long‐distance calls over the Internet to...

Voice networks evolved from the fixed traditional telephone system, to mobile and wireless networks and now towards a converged voice and data infrastructure. This convergence is based on the spread of the Internet Protocol, where VoIP is developing. Due to IP network characteristics, hackers are able to compromise and take control of different aspects of IP telephony such as signaling informat...

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...

A bstmctInternet and cellular technologies are merging to decrease transport costs and enable IP-based applications t o hundreds of millions of cellular users. Real time voice services will continue t o be dominant in future cellular systems and t o reduce system costs it is desirable t o base all services, including voice, on IP. However, the radio spectrum must be efficiently used to provide ...

Voice over Internet Protocol (VoIP) is a form of voice communication that uses audio data to transmit voice signals to the end user. VoIP is one of the most important technologies in the World of communication. Around, 20 years of research on VoIP, some problems of VoIP are still remaining. During the past decade and with growing of wireless technologies, we have seen that many papers turn thei...

VoIP (Voice over IP) is a service that requires synergy between the underlying network for transport and the endpoints responsible for voice processing. We evaluate the end-to-end quality and performance of several VoIP end-points. In particular, we focus on the following aspects: mouth-to-ear (M2E) delay, clock skew and behavior under packet loss. Our measurement results show that M2E delay de...

In the early eighties, a communications protocol was created that allowed the research community to send data anywhere in the world using packet switching networks. This protocol became known as TCP/IP and ultimately resulted in the creation of the revolutionary Internet. TCP/IP actually refers to a suite of different protocols but, at its core, there exists the fundamental protocol commonly re...

Voice over IP (VoIP) is an emerging communication service allowing voice transmission over a private or a public IP network. VoIP allows significant benefits for customers and service providers including cost savings, phone and service portability, mobility, and the integration with other applications. Nevertheless, the deployment of the VoIP technology encounters many challenges such as intero...