Approximate fairness through limited flow list

Most of router mechanisms proposed for fair bandwidth sharing lack either (1) simplicity due to complexity of intricate per flow management of all connections (e.g., WFQ, SFQ), (2) heterogeneity due to a design targeting a specific traffic type, e.g., RED-PD and Fair RED (FRED) or (3) robustness due to requirement for proper router configurations (e.g., CSFQ). All of these severely impact the scalability of the schemes. This paper proposes a novel router fairness mechanism, namely Approximate Fairness through Partial Finish Time (AFpFT). Key to the design of AFpFT is a tag field the value of which defines the position of the packet in an aggregate queue shared by all flows. The specific of tag computation depends on the router's role — edge or inner — to the flow. While gateways closest to traffic source manage all flows, successive or inner routers only manage a limited subset at flow level. The managed flows are usually of higher rates than fair share. Following the heavy-tailed Internet flow distribution, these flows are indeed the minority in the Internet. Using extensive simulations, we show that the scheme is highly fair and potentially scalable unlike other proposed schemes.