QoStat ' A Tool for the Evaluation of QoS-capable Routers
Authors
Abstract
At the Laboratory of Communications and Telematics of the University of Coimbra we have been working on the IP QoS field. Our work includes researching, testing and implementing mechanisms that can be used on current IP networks in order to make them able to provide different performance levels to traffic with different QoS needs.Our work is being supported by a testbed of INTEL hosts running the FreeBSD operating system patched with ALTQ software. This is a common platform in this research field. We chose it, in part, for that reason - there is much work produced for this environment in which we are interested - and also because it is fully open, allowing us to freely test new
approaches for QoS provision.
Despite the amount of work being done in this area, soon we realized the lack of a tool to monitor with detail the operation of the IP layer on routers, in particular, the mechanisms related to QoS provision. It was evident we needed such a tool, so we decided to implement one - which we named QoStat.
This paper presents QoStat a GUI based tool, which gives us the possibility to visualize in real time the most important values related to QoS provision. With it we can also change on the fly the most important operational parameters of the mechanisms associated with QoS provision. In this way, it is possible to understand with depth the behavior of those
systems - for instance, to study cause-effect relations between the values of the referred parameters and the QoS in fact provided to the different IP traffic flows or classes.