Experimental characterization of QoS in commercial ethernet switches for statistically bounded latency in aircraft networks

Aircraft networks are used to service mission-critical avionics systems as well as cabin systems such as in-flight entertainment. These networks require that the switches used offer line-rate switching as well as bounded latency and jitter. Gigabit Ethernet offers an interesting replacement to traditional proprietary networks because of its high performance and low cost. In this paper we develop a framework for analyzing the abilities of Gigabit Ethernet switches to provide probabilistic guarantees for reliably low latency using Quality of Service (QoS) controls. From the perspective of control capabilities, management complexity, and implementation success we compare the strengths and weaknesses of three modern Ethernet switches. These switches exhibit a broad range of configuration options and are representative of the different levels of QoS implementation available today. We use the performance metrics of latency, jitter, and packet loss to characterize the success of a service policy. The results from a variety of network, load, and traffic scenarios are presented in terms of these metrics. Through the results, we are able to gain insight into the individual switch implementations of QoS.