Voice over IP (VOIP) has strict Quality of Service (QoS) constraints and requires real-time packet delivery, which poses a major challenge to IP networks. The Cognitive Packet Network (CPN) has been designed as a QoS-driven protocol that addresses user-oriented QoS demands by adaptively routing packets based on online sensing and measurement. This paper presents our design, implementation and e...

Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies to delivery of voice communications over IP networks such as the Internet or other packet-switched networks. VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codecs which encode speech allowing transmission over an IP network as digital audio...

The proliferation of communications over networks based on Internet Protocol (IP) technology imposes ever growing challenges for Law Enforcement Agencies. This Aqsacom White Paper provides an introductory background on the issues behind lawful interception as applied to IP networks and their overlying applications, with emphasis on the dominant applications of E-mail and Voice-Over-IP (VOIP).

Voice communications on IP networks use owner protocols as well as standards like SIP, MGCP and H323. In this paper we propose a new method for transparent traversal of NATed (Network Address Translated) networks for the SIP (Session Initiation Protocol) protocol. Although SIP is an application layer protocol, its operation is affected by address translation. This is because SIP uses network la...

In this paper, we analytically compare IP versus AAL2/ATM as a transport technology in the UMTS Terrestrial Radio Access Network (UTRAN), where stringent delay bounds are to be met for both real-time and non real-time traffic. We particularly select voice and Web traffic so as to illustrate our investigation. We show that, for the case of voice traffic, AAL2/ATM has a small advantage over IP, i...

Voice over LTE (VoLTE) emerges as the basis for voice services in future cellular networks. At the same time, Quality of user Experience (QoE) assessment methods have notably evolved in the last years, especially for Voice over IP (VoIP) services. The question that rises is, are these models ready to be used for VoLTE? In this paper, we contribute to answer this question by: (i) providing a hig...

The Voice over IP (VOIP) and the IP based internet services are revolutionizing the way wireless networks are developed. The VOIP services make use of the internet backbone rather than the traditional circuit based networks (PSTN and the wireless voice services). The advantage provided by the VOIP technology over the traditional circuit based networks is that both voice and data signals are tra...

The rapid growth of IP-based packet switched network and the overall bandwidth efficiency of an integrated IP network make it an attractive candidate to transport real time voice connections. However, high quality voice over IP (VoIP) remains a challenge because interactive voice imposes many performance requirements (such as loss rate and latency) on the transport network. This cannot be easil...

Abstract Quality of Service (QoS) is critical for the success of real time applications over IP, such as Voice over IP (VoIP). On voice gateways, Call Admission Control (CAC) plays an important role for guaranteed QoS, for it makes decisions on whether and how to deliver the traffic based on different kinds of resources. In our study, we propose the measurement-based CAC model based on the vari...