Users of Voice over IP (VoIP) applications are sensitive to the quality of an ongoing call. We hypothesize that the quality of a VoIP session can be estimated from the first few seconds of the session and this can be generalized to other VoIP calls. Our approach is an in-band probing mechanism and does not require any external monitoring schemes or network support. We show by post processing Vo...

With the appearance of new Internet services like Voice over IP and IP television, malwares are in the way to update and extend their targets. In this paper, we discuss the emergence of a new generation of malwares attacking VoIP infrastructures and services. Such malwares constitute a real threat to the currently deployed VoIP architectures without strong security measures in place. We present...

-------------------------------------------------------------------ABSTRACT---------------------------------------------------Voice over Internet Protocol (VoIP) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. VoIP provides a protected transmission of private voice data betwee...

Deploying IP telephony or voice over IP (VoIP) is a major and challenging task. This paper describes an analytical design and planning simulator to assess the readiness of existing IP networks for the deployment of VoIP. The analytical simulator utilizes techniques used for network flows and queueing network analysis to compute two key performance bounds for VoIP: delay and bandwidth. The simul...

In Pakistan, the VoIP service is gaining popularity. By the end of 2014, the total number of broadband subscribers exceeded 3.35 million and the total number of mobile 3G subscribers were approximately 4 million. The service providers in Pakistan continue to invest in infrastructure and supporting regulatory policies fueling the development of infrastructure. It is expected that such an environ...

Voice over Internet Protocol (VoIP) is being widely deployed to offer users low-cost alternatives for long-distance and international telephone calls. However, for users who are accustomed to the high-quality sound offered by traditional Public Switched Telephone Network (PSTN) service, VoIP voice quality often pales in comparison. Voice quality in VoIP networks widely varies as a result of sev...

Voice-over-IP (VoIP) technology has come of age and is quickly gaining momentum on Broadband networks. VoIP packetizes phone calls through the same routes used by network and Internet traffic and is consequently prone to the same cyber threats that plague data networks today. These include denial-of-service attacks, worms, viruses, and hacker exploitation. In addition to these traditional netwo...

Voice over Internet Protocol (VoIP) over Wireless Local Area Networks (WLANs) is an important application of WLANs and it has gained more and more attention recently. In this article, we analyse the maximum number of VoIP calls supportable in a WLAN and propose a new call admission control strategy, namely, Adaptive Transmission Interval Call Admission Control (ATICAC) to enhance VoIP calls in ...

The quality of speech signal over a VoIP system is degraded by various network layer problems which include jamming, jitter, packet loss. Different types of noises also degrade the quality of speech signal such as external noise and quantization noise. This paper improves the quality of VoIP speech signal affected by these noises and network layer problems. The quality of degraded VoIP speech s...

VoIP has become a major application of multimedia communications over IP. Many initiatives around the world focus on the detection of attacks against VoIP services and infrastructures. Because of the lack of a common labeled data-set similarly to what is available in TCP/IP network-based intrusion detection, their results can not be compared. VoIP providers are not able to contribute their data...