Flow-valve: embedding a safety-valve in RED

In this paper, we present the flow-valve, a safety-valve mechanism for RED (random early detection) to protect the network from misbehaving or overpumping flows and to promote end-to-end congestion control. The flow-valve can be regarded as an implementation of the concept known as a “RED penalty-box” but our focus is to protect router resources in times of congestion. The flow-valve detects a traffic increase that goes beyond the control range of RED, and protect the local resources by forcing overpumping flows to back off. The flow-valve provides an incentive for end-to-end congestion control to keep the packet drop rate low under moderate congestion, and to conservatively back off under heavy congestion. Our simulation results demonstrate that the flow-valve can effectively protect the network from misbehaving flows and, at the same time, isolate undesirable behavior of conformant TCP. The flow-valve also has been successfully implemented onto FreeBSD