Simulation study on the effect of the trTCM parameters

Abstract

In this paper, we study the effect of the trTCM parameters on policing accuracy via computer simulation. The trTCM (two-rate three-color marker) is a traffic conditioner and can be used as a policing/limiting mechanism in Differentiated Services networks. The trTCM algorithm described in RFC 2698 [7] is configured using 4 traffic parameters: CBS (committed burst size), PBS (peak burst size), CIR (committeed information rate), and PIR (peak information rate). With these parameters, it marks incoming packets either green, yellow, or red. Packets marked green is always queued and delivered to the output side, but packets marked yellow or red are either queued or dropped depending on the policing policy of the network. Among them, green packets are related to the policing rate and, therefore, policing accuracy. The policing rate of the trTCM algorithm is determined by CIR. By contrast, policing accuracy is influenced by other trTCM parameters. Our findings in this study is that the policing accuracy of the trTCM is maximized when we use PIR, which is equal to CIR, and CBS, which is larger than twice the maximum packet length. PBS has no influence on the policing accuracy.