Jetmax: Scalable max–min congestion control for high-speed heterogeneous networks

Abstract

Recent surge of interest towards congestion control that relies on single-link feedback (e.g., XCP, RCP, MaxNet, EMKC, VCP), suggests that such systems may offer certain benefits over traditional models of additive packet loss. Besides topology-independent stability and faster convergence to efficiency/fairness, it was recently shown that any stable single-link system with a symmetric Jacobian tolerates arbitrary fixed, as well as time-varying, feedback delays. Although delay-independence is an appealing characteristic, the EMKC system developed in exhibits undesirable equilibrium properties and slow convergence behavior. To overcome these drawbacks, we propose a new method called JetMax and show that it admits a low-overhead implementation inside routers (three additions per packet), overshoot-free transient and steady state, tunable link utilization, and delay-insensitive flow dynamics. The proposed framework also provides capacity-independent convergence time, where fairness and utilization are reached in the same number of RTT steps for a link of any bandwidth. Given a 1mb/s, 10gb/s, or googol (10^1^0^0) bps link, the method converges to within 1% of the stationary state in six RTTs. We finish the paper by comparing JetMax's performance to that of existing methods in ns2 simulations and discussing its Linux implementation.