Section: New Results

Home Network or Access Link? Locating Last-mile Downstream Throughput Bottlenecks

Participants: Srikanth Sundaresan (ICSI), Nick Feamster (Princeton), Renata Teixeira

As home networks see increasingly faster downstream throughput speeds, a natural question is whether users are benefiting from these faster speeds or simply facing performance bottlenecks in their own home networks. We studied the problem whether downstream throughput bottlenecks occur more frequently in their home networks or in their access ISPs. We identified lightweight metrics that can accurately identify whether a throughput bottleneck lies inside or outside a user's home network and developed a detection algorithm that locates these bottlenecks. We validated this algorithm in controlled settings and characterized bottlenecks on two deployments, one of which included 2,652 homes across the United States. We found that wireless bottlenecks are more common than access- link bottlenecks—particularly for home networks with downstream throughput greater than 20 Mbps, where access-link bottlenecks are relatively rare.