Home Access Congestion Points

Home Network or Access Link? Locating Last-mile Downstream Throughput Bottlenecks - See more at: https://www.nanog.org/meetings/nanog64/agenda#sthash.jjudtWT6.dpuf

  "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. In this work, we study a simple question: Are users’ downstream throughput bottlenecks in their home networks or in their access ISPs? Although our question is simple, answering it on a large-scale deployment is challenging because accurate measurements require instrumentation of a home router, which is too resource-constrained for many existing throughput analysis tools. In this work, we identify lightweight metrics that can accurately identify whether a throughput bottleneck lies inside or outside a user’s home network and develop a detection algorithm that accurately locates these bottlenecks. We validate this algorithm in controlled settings and report on two deployments, one of which is the FCC deployment with 2,652 homes in the United States. We find 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. In homes with a wireless bottleneck, it is equally likely that only one device experiences the bottleneck as it is for all devices to experience the wireless bottleneck simultaneously."

Locates analysis on the home router - useful for carriers that provide a home router and are willing to instrument it. Uses data to try to discover where the bottlenecks may be located. Uses pcap to collect 10K pps samples about 3x per hour to avoid load on limited home router resources. Looks at the level of packets in buffers to detect "bottleneck"

First platform was Netgear WNDR3700v2 - 64 homes worldwide
Second test Netgear WNR 3500L, fewer resources but got into 2600 homes in US (FCC assisted with this?)

Found significant bottleneck 40-50 percent of the time across most users. Conflates both access link and wifi.

Found that most issues are wifi overload. As soon as carrier throughput increases above 20 Mbps, then bottleneck moved from access link to wifi link. Wifi bottlenecks at 20 Mbps.

Were able to determine on one of the router platforms with two radios that 2.4ghz was an issue and that 5 ghz performed better. Note that ATT residential gateway does not provide 5ghz. So "gigapower" is being delivered to most customers over 2.4ghz.