Flow-Aware Low-Latency Multipath Tunnelling

Multipath Tunnelling (MT) is an effective approach to increase the reliability and throughput of network connections. In contrast to Multipath TCP (MPTCP) or SCTP, it also works for UDP traffic and its deployment is easy. It requires neither full access to all uplink endpoints nor a multipath protocol implementation in every host. Despite its potential, research on MT is sparse. Most known prototypes use either round robin or MPTCP schedulers that are not able to fully utilize the potential of MT. This paper proposes and evaluates LLMT, a novel specific MT packet scheduling algorithm that achieves very low latency and high throughput for reliable and unreliable traffic. In multiple testbed experiments, we compare LLMT with several schedulers including LowRTT, OTIAS and AFMT for different network configurations. For TCP traffic, LLMT gains low latency and high throughput. For fixed rate UDP traffic, jitter and latency are the lowest among all competitors.