A QoE Perspective on Sizing Network Buffers

Despite decades of operational experience and focused research efforts, standards for sizing and configuring buffers in network systems remain controversial. An extreme example of this is the recent claim that excessive buffering (i.e., bufferbloat) can severely impact Internet services. In this paper, we systematically examine the implications of buffer sizing choices from the perspective of factors impacting end user experience. To assess user perception of application quality under various buffer sizing schemes we employ Quality of Experience (QoE) metrics. We evaluate these metrics over a wide range of end-user applications (e.g., web browsing, VoIP, and RTP video streaming) and workloads in two realistic testbeds emulating access and backbone networks. The main finding of our extensive evaluations is that network workload, rather than buffer size, is the primary determinant of end user QoE. Our results also highlight the relatively narrow conditions under which bufferbloat seriously degrades QoE, i.e., when buffers are oversized and sustainably filled.