Currently, we are witnessing a trend in network routers to include reconfigurable hardware structures to provide flexibility at improved performance levels when compared to software-only implementations. This permits the run-time reconfiguration of the hardware resources, i.e., to change their functionality (for example, from one scheduling algorithm to another), to adapt to changing network scenarios. In particular, different scheduling algorithms are more efficient in handling a specific mix of incoming packet traffic in terms of various criteria (e.g., delay, jitter, throughput, and packet loss). Therefore, reconfigurable hardware is able to provide improved performance levels and to allow more efficient algorithms to be utilized when different incoming packet traffic patterns are encountered. This project investigates the possibilities to improve upon end-to-end delays, jitter, throughput, and packet loss by exploiting the availability of a flexible hardware structure such as an field-programmable gate array (FPGA). The aim of the project is to provide an overview on adaptive scheduling using reconfigurable hardware. Consequently, we investigate different scheduling algorithms that provide QoS provisioning for traffic streams that are sensitive to packet delay and jitter, e.g., mpeg video traffic. The investigation utilizes the NS-2 simulator for which we generate realistic network scenarios. Our approach is based on understanding which kind of traffic is passing in the network, and subsequently change the scheduling algorithm accordingly in the core router to meet specific performance requirements. The investigated scheduling algorithms are taken from two well-known families, i.e., Round Robin (RR) and Fair Queuing (FQ). Our investigation confirmed the idea on the behavior of the two investigated scheduling algorithm: WFQ outperforms WRR in terms of end-to-end delay, jitter and throughput but it is more expensive than it at a computational level. Nonetheless, it is possible to find a tradeoff between the required area in FPGA and the level of performance desired for a kind of stream.
PERFORMANCE ANALYSIS OF RR AND FQ ALGORITHMS IN RECONFIGURABLE ROUTERS
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