A high - end Linux based Open Router for IP QoS networks : tuning and performance analysis with internal ( profiling ) and external measurement tools of the packet forwarding capabilities

The Internet technology has been developed in an open environment; all Internet related protocols, architectures and structures are publicly created and described. On the contrary, and in some sense quite surprising, most of the professional IP equipments are realized in a very “closed” way. Otherwise, in many cases, the “experimental” nature of Internet and its diffusion suggest in many contests a different approach. Moreover, the recent technology advances give a good chance to do something effective in the field of open Internet equipments, sometime called Open Routers (OR). Starting from these considerations, some initiatives have been activated since last few years to investigate the OR and related issues. But despite of these activities, large interesting areas still require a deeper investigation. This work tries to give a contribution by reporting the results of a deep activity of optimization and testing realized on a PC Open Router architecture based on Linux software. The main objectives have been the performance evaluation (with respect to packet forwarding) of an optimized OR, both with external (throughput) and internal (profiling) measurements. Specific tests have been realized for an IP Quality of Service (QoS) aware contest to verify the effectiveness of the flows differentiation and the impact on the performance of classification and scheduling functionalities.