A New BBR with the Low-Pass Filter

BBR is a new congestion-based congestion control algorithm proposed by Google to address the bufferbloat problem. It is designed to achieve the maximum throughput with the minimum RTT by continuously estimating the available bandwidth. Our preliminary evaluation results in this paper show that delay jitters in ACK packets cause overestimation of available bandwidth and accordingly increase of RTT. In this paper, we propose a new BBR rate calculation algorithm, Low Pass Filter based-BBR (LPF-BBR), which mitigating fluctuations of calculated delivery rate. Our evaluation results by computer simulation show that our proposing LPF-BBR can estimate bottleneck bandwidth accurately and prevent increase of RTT caused by overestimation, even in the case that ACK packets suffer delay jitter. As far as we know, this is the first work focusing on influence of backward path congestion in BBR.