Voice over IP (VoIP) service has been widely deployed over the prevalent Internet due to the advanced technologies of digital voice compression, communication protocols, and wired/wireless networks. VoIP then benefitmuch lower cost of equipment, operation, and better integrationwith data applications than voice communications over telephony networks. On the other hand, VoIP further introduce se...

Internet Protocol is used as a communication platform for Voice over Internet Protocol (VoIP). Before the transmission of VoIP it is required to do signal processing for reliable & efficient performance over the computer and the communication platform.Speech quality is critically important to update the service. Signal quality gets deteriorated at network layer due to problems like delay, jitte...

Voice over IP (VoIP) is one of the most popular Internet applications. Many VoIP protocols (e.g. SIP) are based on a central-server scheme in which a caller needs to query the central server first for the callee’s information (e.g. IP address) before it can connect to them. However, such a centralized architecture has some drawbacks, such as an unbalanced load and a single point of the failure....

In February 2003, Cox Communications published “Preparing for the Promise of Voice over Internet Protocol (VoIP),” its first whitepaper on the subject. At that time, VoIP technology was still in its infancy and the need still existed to educate industry analysts and media, as well as our peers, on several fronts, including: the state of VoIP technology and its applications; Cox’s VoIP strategy ...

This contribution evaluates the security of VoIP networks. Potential threats to VoIP networks lead to unbearable risks which need to be eliminated by suitable countermeasures. However, cost and complexity of countermeasures should be adapted to the practical situation. Therefore the protection requirements are assessed. In this contribution the range of possible protection requirements is divid...

Voice Service Providers (VSPs) participating in VoIP peering frequently want to withhold their identity and related privacy-sensitive information from other parties during the VoIP communication. A number of existing documents on VoIP privacy exist, but most of them focus on end user privacy. By summarizing and extending existing work, we present a unified privacy mechanism for both VoIP users ...

——VoIP over Wireless LANs is greatly affected by path-loss, RF interference and other sources of signal attenuation in addition to network congestion. The primary factors involved in effective real-time communication, namely delay and loss, must be within certain controlled limits in such a scenario. Wireless LAN Access Points must, therefore, act in tune with the codecs to ensure high quality ...

With the growth of its popularity, VoIP is increasingly popular nowadays. Similarly to other Internet applications, VoIP users may desire to be unlinkable with their participated VoIP session records for privacy issues. In this paper, we explore the Items of Interests (IOIs) from anonymisation aspects based on a simplified VoIP model and analyse the potential links between them. We address poss...

We investigate whether the current best-effort technology of Internet stands up to the high quality standards of real-time voice communication. More precisely, we assess VoIP quality within the context of transport protocol support and efficiency. Initially, we focus on TCP and UDP supportive role from the perspective of VoIP performance. Applying our metric for real-time performance, we reach ...

The goal of this paper is to provide some feedback on a VoIP project in the German research network. During the last couple of years we build up and managed an unusual large testbed for VoIP applications in Germany. Several universities, research institutes, and companies tied together to allow a common usage to different local VoIP installations. The primary goal of the tests was to identify p...