Management of abusive and unfair Internet access by quota-based priority control

In a free of charge or flat-rate Internet access environment, there often exists abusive and unfair usage of network resources. In this paper, the Internet access by the dormitory users at the National Taiwan University (NTU) serves as a conveyer problem. A quota-based service architecture combined with priority scheduling is developed to resolve the problem of unfair and abusive Internet access encountered in the NTU dormitory networks. The goal is to meet the basic traffic demands of the majority users while limiting abusive usage from ignorant heavy users. Two classes of services are provided. The regular class sets a quota on each user s traffic volume per quota control period. Out-ofprofile or possibly abusive traffic is directed to a lower priority service class called the custody service and served when there is an excess bandwidth. The new policy and schemes are implemented on a quality of service router, a meter reading server, an accounting server and a Web-based service management server with minimal intrusion of user privacy and least disturbance to the existing service offering. The experimental results show that the original congestion at the bottleneck link was alleviated with a 48.9% reduction of the average packet drop rate. Abusive Internet access by the top 2% heavy users is greatly reduced by 57.82%. Astonishingly, over 91% users are pleased with this new policy and their network usages all increase. This is a win–win result. Under the new policy and implementation, users paying the same amount of service fee are now able to fairly share resources. A mathematical model for prediction of control effects is also presented. The experimental results are consistent with the prediction of the model. 2003 Elsevier B.V. All rights reserved.