Archive for April, 2020

Bufferbloat in Action due to Covid-19

April 22, 2020

Four people now live and work in my home 24×7; my wife Andi, her mother, my daughter and myself. Many of you now live in similar situations.jigsawfish2

Very occasionally, everyone will have network trouble, such as occurred to us this morning. Sometimes it is our “last mile” connection: it is easy to see these failures in our cable modem log. (Often available by looking at the address, which seems to be the default address for cable modems.). Occasionally it can be the ISP (in our case, Comcast), either due to some routing failure or DNS failure. These can be harder to diagnose.

Bufferbloat, however, is insidious. It comes and goes, and most users have been “trained” to ignore temporary bad behavior over many years. When you go to diagnose it, you usually stop the operation that is causing it. This blog has recorded our efforts to fix bufferbloat. Now that there are many more people at home at the same time trying to do more demanding applications, this problem is much more common. Other people in your home can inflict the bufferbloat problem on you without you or they understanding what is happening.

Yesterday afternoon my I was helping my wife learn how to edit videos that now makes and uploads for her students, and one of her co-workers, who we’ll callĀ  “Carleen”, called on a video to chat on planning classes. Those of you who wonder what teachers do when not teaching should understand that not only do teachers grade materials and give other feedback to students, but also spend much of their time preparing future classes. The amount of “prep” time diminishes the more often a good teacher has taught a given subject, but never drops to anything close to zero. At the moment, learning to teach remotely is an extreme extra burden.

In the first phase of learning from home, assignments to students consisted of watching videos and performing on line work sheets. None of these activities are latency sensitive. As of this week, however, the next phase of instruction includes teachers attempting more “conventional” instruction via on-line teleconferencing (Google Meet, in their case). Teleconferencing is by its nature very latency sensitive.

Carleen shares her home with her husband and two sons of age seven and ten. She commented that yesterday she her class had been aborted entirely due to intermittent network problems caused by her kids game playing. She has now banished her kids from their video games during her class times, but this may be worse than the disease with two bored children in the house; only time will tell. Transient problems caused by bufferbloat now really matter to her, and to her class.

In my early bufferbloat talks, I called bufferbloat the “The Internet is Slow Today, Daddy” problem. But anyone can inflict pain on others sharing a connection if bufferbloat is present; it is just as much a “Kids, quit what you are doing so I can teleconference” problem. Thankfully, I can now make concrete recommendations on how you can solve bufferbloat in your environment. My “go to” recommendation for non-geeks is currently the EvenRoute IQRouter. This device will both mitigate bufferbloat in your “last mile”, and fix it in the WiFi link to your device, without any manual tuning. At this moment, I am not aware of any other home router that deals with bufferbloat both in the “last mile” and in WiFi; either or both can be a problem at any given instant..

Needless to say, I recommended that Carleen buy one of those routers.

I wish that all ISP’s would increase the upstream bandwidth of all connections to teachers for the duration of the Covid-19 crisis, which would help diminish the bufferbloat problem (bufferbloat is generally most severe in the upstream link, and many teachers cannot afford expensive tiers of Internet service). Those hurt most by bufferbloat are those with the most minimal service; not only impecunious teachers, but also the students whose parents are least able to afford higher tier internet service.

A few network speed test sites have tests for bufferbloat, such as DSLReports Speedtest but there are many ways to text explicitly for bufferbloat, as outlined here.