DESIGN AND ANALYSIS OF NETWORK MODELS FOR QOS ROUTERS ON UDP AND CBR
No Thumbnail Available
Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
Georgian Technical University & St Andrew University of Patriarchy of Georgia
Abstract
To address the issues of packet delay and unfairness among multimedia UDP flows, this paper presents the design and evaluation of network models to study different parameters for quality-of-service (QoS) provisioning in differentiated service (DiffServ) routers using user datagram protocol (UDP) as network traffic agent and constant bit rate (CBR) as traffic generator. Traffic marker algorithms are used to define the treatment an incoming traffic (packet streams) receives at the edge routers in a DiffServ domain. In order to implement the TSW2CM and TSW3CM marker algorithms, a network model was designed. The designed models were simulated, analysed and evaluated. For the purpose of evaluation, packet delay and fairness index were considered. The obtained evaluation results were analysed based on a ranking system approach to showcase the strengths and weaknesses of the TSW2CM and TSW3CM algorithms for multimedia UDP flows. The adopted approach showed that the TSW3CM algorithm was ranked first with a packet delay value of 0.237704 while TSW2CM algorithm was marked second (with 0.431778), and the TSW3CM algorithm was ranked first with a fairness rate value of 0.3823960 while TSW2CM algorithm was ranked second (with 0.2817353). The obtained results indicate that applications that requires low packet delay can be deployed on UDP protocol using TSW3CM algorithm while applications that requires high fairness rate values can be deployed on UDP protocol using TSW3CM algorithm.
Description
The influx of multimedia applications such as Video on Demand (VoD), Voice over Internet Protocol (VoIP), to mention a few, on the Internet in recent years has increased astronomically and this demands for Quality of Service (QoS) assurance due to the sensitive nature of these applications and their varying QoS requirements such as packet delay rate, packet loss rate, fairness, throughput [1]. These applications transits through a network as traffic and they are often confronted with congestive messages such as “try again or network busy” due to weaknesses of ancient TCP/IP protocol suite to provide QoS in a differentiated manner based on different traffic demands of incoming traffic stream. In order to meet the different QoS requirements of different multimedia applications, the Internet Engineering Task Force (IETF) came up with two Internet architectures, namely the integrated service (IntServ) architecture and the differentiated service (DiffServ) architecture [2]. The emergence of the IntServ can be described as an evolution of the best-effort service architecture. However, the IntServ architecture is confronted with a number of issues such as scalability which is mostly experienced in the core router. IEFT improved on this problem and came up with a new architecture called DiffServ. The DiffServ is able to provide a scalable edge-to-edge QoS within a single domain but it is also faced with unfairness problem that occur in DiffServ networks [3-5]. The DiffServ treats traffic (packet stream) through QoS service differentiation mechanisms namely the traffic classification and traffic conditioners. It uses a conditioner at the boundary of the DiffServ network to mark packets. Packets marking is done at the edge domains using traffic markers before traffic flows enters into the network core and packets are marked as either in-profile or out-profile. The traffic marker algorithm is used to define the treated to be accorded a traffic (packet streams) as it transverses through a DiffServ domain. Through IETF, time sliding window (TSW) based traffic marker algorithms have been proposed in recent years through Request For Comment (RFC), namely the Time Sliding Window Two Color Marker (TSW2CM) and Time Sliding Three Color Marker (TSW3CM). This study is aimed to analyse and evaluate the variants of TSW marker algorithms namely TSW2CM and TSW3CM on user datagram protocol (UDP) as network traffic agent for QoS assurance in the Internet.
Keywords
Internet QoS, fairness rate, TSW2CM, TSW3CM, IETF, packet delay