A New Queue Discipline for Reducing Bufferbloat Effects in HetNet Concurrent Multipath Transfer

Abstract: Heterogeneous wireless networks have evolved to reach application requirements for low latency and high throughput on Internet access. Recent studies have improved network performance employing the Multipath TCP, which aggregates flows from heterogeneous wireless interfaces in a single connection. Although existing proposals are powerful, coupled congestion control algorithms are currently limited because of the high variation in path delays, bandwidth and loss rate, typical from heterogeneous wireless networks, even more over concurrent multipath transmissions. These transmissions experience bufferbloat, i.e., high delays caused by long queues. Hence, to cope with the current limitations, this work presents CoDel-LIFO, a new active queue management (AQM) discipline to reduce the dropped packet ratio in the Multipath TCP congestion control mechanism. Differently from other approaches, CoDel-LIFO gives priority to the most recent packets, being then promising. This paper provides a detailed simulation analysis over congestion control algorithms by comparing CoDel-LIFO to CoDel and DropTail disciplines. Results indicate that CoDel-LIFO reduces queue drops, diminishing the impact on congestion control; improving substantially the goodput; and keeping RTT low.