Supporting multimedia applications through network redesign

Abstract

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. INTRODUCTIONMultimedia applications combine various types of media such as audio, data, and video, where these media place high demand over stringent QoS to satisfy the users' community. Most of the data networks are Ethernet based and the network administrators find it extremely advantageous and cost effective to deploy multimedia applications over existing networks. However, the multimedia applications are sensitive to timely packet delivery with minimal delay, minimum jitter and packet loss, whereas traditional data networks are characterized by their burst traffic and high bandwidth demand at burst time. Moreover, the data networks are designed for nonreal time applications [1]. Therefore, the network administrators face real challenges in attaining high quality calls while implementing services like voice over Internet protocol (VoIP), which imposes to explore the capacity of the network prior to multimedia application deployment.Poor predeployment analysis and lack of preplanning tools may cause unsuccessful implementation of VoIP over the underlying data network. It is advisable to evaluate the number of VoIP calls that a network can handle before upgrading prematurely any part of the existing network. Furthermore, the existing data network with low quality has to be improved before deploying the multimedia applications. COMPUTER NETWORK REDESIGN 431Network simulation is one of the most predominant assessment methodologies in the area of computer networks. Even though network simulators can be divided into several categories (by protocol, technology or processing method), most general categorization is their method of simulation: discrete event or analytical simul...

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