The popularity of Voice over the Internet Protocol (VoIP) is increasing as the cost savings and ease of use is realised by a wide range of home and corporate users. However, the technology is also attractive to criminals. This is because VoIP is a global telephony service, in which it is difficult to verify the user’s identification. The security of placing such calls may also be appealing to c...

Wireless Mesh Networks (WMNs) are seen as a means to provide last mile connections in Next Generation Networks (NGNs). Because of their auto configuration capabilities and the low deployment cost WMNs are considered to be an efficient solution for the support of multiple voice, video and data services in NGNs. This paper looks at the optimal provision of resources in WMNs for Voice over IP (VoI...

This paper addresses the issue of cost-optimal voice over IP (VoIP) network design. In the applied model, the whole VoIP network is divided into two logical components: the access network and the transport network. The access network consists of VoIP end-points that connect to the transport network through edge routers serving as gateways. Since multiple edge routers may be available for any gi...

The usage of voice over IP (VoIP) traffic in IEEE 802.11 wireless networks is expected to increase in the near future due to widely deployed 802.11 wireless networks and VoIP services on fixed lines. However, the quality of service (QoS) of VoIP traffic in wireless networks is still unsatisfactory. In this thesis, I identify several sources for the QoS problems of VoIP traffic in IEEE 802.11 wi...

Increasing popularity of VoIP systems has witnessed applications in emerging technologies like Cognitive Radio Networks (CRN). The stringent QoS requirements in VoIP coupled with complexities in CRN have initiated intensive research in the field of performance analysis and optimizations guided by simulation results. However, in the absence of any standard model of VoIP over CRN, accuracy and cr...

IP telephony (Voice over IP – VoIP) has become an important driver for packet-based communications. The impact of the growing VoIP traffic on communication networks, especially backbone networks cannot be neglected. Telecom service providers must be aware that VoIP is the newest, fast-growing alternative for voice communication. Unlike voice transmission over the public telephone network, VoIP ...

Switching a communication path from one Access Point (AP) to another in inter-domain WLANs is a critical challenge for delaysensitive applications such as Voice over IP (VoIP) because communication quality during handover (HO) is more likely to be deteriorated. To maintain VoIP quality during HO, we need to solve many problems. In particular, in bi-directional communication such as VoIP, an AP ...

Voice-over-IP (VoIP) systems are increasingly prevalent in our lives. These systems come in a wide variety of flavors such as desktop-based software applications (e.g., Skype [26]), systems that replace public switched telephony network (PSTN) as the primary line voice service (e.g., Vonage [29]), and more recently, VoIP over smart phones. In November 2010, the number of concurrent VoIP users o...

Voice over IP (VoIP) in 802.11 wireless networks (WiFi) is an attractive alternative to cellular wireless telephony. Unfortunately, VoIP traffic is well known to make inefficient use of such networks. Indeed, we demonstrate that increasing handset deployment has the potential to cripple existing hotspot and enterprise WiFi networks. Our experiments show that VoIP halves the available TCP capaci...