Tahani Hussain

Supporting multimedia applications through network redesign

Recent evolutions in high-performance computing and high speed broadband Internet access have paved a way to enterprise-wide multimedia applications, which require stern QoS from the underlying networks. In this paper, we have explored threefold studies on existing enterprise network, whereby we proposed an analytical approach to evaluate the performance of the existing network; we have examined the feasibility of existing enterprise networks to accommodate voice over Internet protocol VoIP services with acceptable QoS, and we have redesigned the enterprise network to accommodate VoIP services to comply with the user defined QoS. The network performance is evaluated by number of VoIP calls sustained by the network, bandwidth utilization, loss rate and latency through Network Simulation NS-2 tool. We have derived a cost model to show the cost-effectiveness of VoIP services over telephonic network. For a medium-size enterprise network of 200 clients and 9 servers, our simulation results show that the redesign improves the network performance by increasing the number of VoIP calls by 57% and decreasing bandwidth utilization and packet loss rate by 20% and 7%, respectively. Moreover, the proposed network redesign demonstrates that the network can be scalable and it can handle up to 4% increased voice calls in the future maintaining QoS standards. Copyright

Assessing and Redesigning Enterprise Networks through NS-2 to Support VoIP

Abstract In the recent past, Voice over IP (VoIP) deployments over data networks are gaining popularity due to the massive growth in the broadband internet access. Successful deployment of these applications depends directly on the performance of the underlying data network. Based on this and the fact that todays data networks are operated to perform many significant applications, network administrators seek out a way to measure the impact of these applications on the existing network performance before deploying them. O ccasionally, network redesign is necessity; considering redesigns alterations should preserve most of the existing network characteristics to reduce overall impact of deploying new applications in the network performance. In this paper, we evaluated readiness of the existing enterprise network through NS-2 to support VoIP and based on findings a solution for redesigning the enterprise network is proposed to enhance the new network performance and leaving sufficient capacity for future growth. We applied our approach on a medium size enterprise network as a case study, the results prove improvements in network performance after redesigning the existing enterprise network.

Enterprise Network Sustainability through Bio-inspired Scheme

Sustainability is best observed within bio-organisms, where they undergo spatial and temporal evolution in their gene expressions to sustain. with constantly changing environment. Maintaining sustainability of Enterprise Networks (EN) is a challenging problem, especially in evolving its infrastructure and data system over time. In this paper, we have proposed a custom-made bio-inspired scheme to provide sustainable operations within EN considering the quality-of-service (QoS) to manage the traffic outbursts at the network infrastructure and at data depositories. Our scheme involves simulating EN with various workloads, formulating EN sustainability problem as an optimization problem, and utilizing of a family of bio-inspired algorithms, such as Genetic Algorithm (GA), Simulated Annealing (SA) and Tabu Search (TS), to search the sustainability space. Our computational experiments illustrate the feasibility of our scheme on a mid-size EN with 40% reduction in the traffic flow at the backbone and with 13.9% increasing in the storage system throughput.

An Approach to Evaluate the Performance of Web Application Systems

The web applications have become fundamental part of every days life and their well-performing have become essential. This paper proposes an approach to evaluate the performance of web application system throughout the developing process. The approach consists of three Java models: workload, simulation and performance analyzer. Workload model aims to mimic a set of real users accessing the web application system. While the second model intentions to log performance measurements of web application system through simulation, the performance measurements are evaluated by the last model. For this work, average response time, total number http of requests and throughput are considered for web application performance metrics. The related experiment results are compared with actual hosted system and found that they are close with an average variant of 7.8% from the real performance measurements.