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According to Forbes collected data, the public cloud services market will rise in 2016 and is expected to grow to $105 billions and, in fact, Virtual Machines (VMs) are one of the most popular tools for building “Cloud” services. But in service delivery such composition of multiple components greatly complicate analysis of product quality, especially if it is about Voice over IP (VoIP) set of services,...
In this work we seek to achieve VoIP end users' profile privacy without violating the QoS constraints on the throughput, end to end delay, and jitter, as these parameters are the most sensitive factors in multimedia applications. We propose an end-to-end user anonymity design that takes into consideration these constraints in a hybrid environment that involves ad-hoc and infrastructure networks. Using...
This paper investigates and compares the performance of the popular VoIP codecs G.711, G.723.1 and G.729A over an IP network based on SIP architecture, using RTP as a transport protocol. This is based on different simulations in order to evaluate the performance of each codec and to find the optimal codec. For this objective this paper analyzes Quality of service (QoS) parameters, principally delay,...
The Internet has now become such an important infrastructure that is capable of sending information within a very short time and easy to access. It is considered as public networks that provide affordable WAN services to most customers. Applications such as video conferencing, file transfer protocol and VoIP are the example of typical network applications supported by the Internet Protocol. Various...
VoIP is replacing traditional telephony system over PSTN as a more affordable communication tool on account of convergence of networks. Meanwhile, security issue brings more attention and becomes more important. SIP is based on text message. This makes the protocol easy to implement but also creates opportunity for hackers to steal or modify the messages. There exist a various approaches to secure...
Enhanced Distributed Channel Access (EDCA) is a mandatory part of the IEEE 802.11e standard which provides Medium Access Control (MAC) layer solution for Quality of Service (QoS) provisioning in Wireless Local Area Networks (WLANs). It is a contention based protocol which prioritizes channel access to QoS traffic using four Access Categories (ACs). In this paper, we introduce the performance evaluation...
VoIP systems have to face far tougher security threats than their underlying IP infrastructure. In fact, a security hole in a VoIP infrastructure could bring to a major security failure for the interconnected PSTN network(s), usually regarded as a reliable and secure domain. This is the reason why before connecting a private VoIP network to the carrier infrastructure, a great number of tests have...
3G Long Term Evolution (LTE) is an all internet protocol (IP) based network and one of its main aims is to improve mobile multimedia services. This is achieved through streamlining the system for packet services. This leads to improvements in the form of higher bit rates, lower latencies, and a variety of service offerings. However, more challenging technical difficulties may be expected to arise...
Next Generation Wireless Networks (NGWNs) focus on convergence of different Radio Access Technologies (RATs) providing good Quality of Service (QoS) for applications such as Voice over IP traffic (VoIP) and video streaming. The voice applications over IP networks are growing rapidly due to their increasing popularity and cost. To meet the demand of providing high-quality of VoIP at anytime and from...
This paper describes an implementation for monitoring the Quality of Service (QoS) and expecting the Quality of Experience (QoE) of a voice communication in a Real-time Transport Protocol (RTP) based telecommunication environment. The resulting QoS parameters are evaluated, the QoE is determined with the E-Model and processed for graphical presentation. With the use of some open-source programming...
Voice over IP “VoIP” is a form of voice speech that uses data networks, for transmission of voice traffic over IP-based networks to transmit voice signals. The signal is correctly encoded at one end of the communication channel, sent as packets through the data network, then decoded at the receiving end and transformed back into a voice signal. It has a potential and offering a choice to the traditional...
This paper proposes a solution for throughput and stringent delay problems of VoIP in Ad-Hoc mode of IEEE 802.11 WLAN standards. This paper analyses the behaviour different codecs and schemes of WLAN running on VoIP traffic and draws a conclusion on the performance of network based on the criteria of different QOS parameters. Later the suitability of different routing protocols like AODV, DSR, OLSR...
Quality of Service (QoS) of a network has become the core research area in a computer communication field. Normally researchers will be using simulation software to carry out their research works. However, it is found that simulation software has its own limitations as it does not really reflect the actual network environment. Thus, most research and development works now are exploiting emulation...
One of the main goals of moving to Next Generation Networks (NGN) is an integrated access to multimedia services like VoIP, and IPTV. The primary signaling protocol in these multimedia services is Session Initiation Protocol (SIP). This protocol, however, is vulnerable against attacks, which may reduce the Quality of Service (QoS), an important feature in NGN services. One of the most frequent attacks...
This paper discusses the viability of using Session Initiation Protocol (SIP) transport for Smart Grid signaling. Smart grids will jointly optimize energy production and demand, in a scenario with millions of smart meters and microenergy sources (e.g. solar panels or electric cars). This will place stringent requirements on telco networks. Information technologies will have to provide scalable signaling...
The entire telecommunications and services world has focused its attention on the newest 3GPP architecture, 4G. Proposing high speed data transfer, all flat-IP network for the core systems and stronger authentication and AAA methods, this architecture seems to be the answer for the mobile networks of the future. Another architecture described by 3GPP as well, but based on IETF standards is the IMS...
Multi-channel multi-radio wireless networks improve network performance by enabling more simultaneous transmissions. Among multi-channel multi-radio protocols, the hybrid multi-channel approach has been shown to be efficient in providing higher system throughput. Voice over internet protocol (VoIP) service is expected to be widely supported in wireless networks, though its capacity has not been studied...
This work presents a study of RTP multiplexing schemes, which are compared with the normal use of RTP, in terms of ITU R-factor quality estimator. The bandwidth saving of the different schemes is studied, and some tests with VoIP traffic are carried out in order to compare R-factor using three different router buffer policies. Network delays are added using an adequate statistical distribution. The...
Due to the increase in demand for reconfigurability in embedded systems, schedulability in real-time task scheduling is challenged by non-negligible reconfiguration overheads. Reconfiguration of the system during task execution affects both deadline miss rate and deadline miss distribution. On the other hand, Quality of Service (QoS) in several embedded applications is not only determined by deadline...
IP networks are increasingly being used for the provision of real time media services. This raises new challenges for QoS assurance through real time monitoring due to the complexity of distribution and the need for information correlation across a number of protocols. New tools and approaches are being developed. In this paper we report early results on one such tool, DRAI. In particular we show...
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