Sunday, March 22, 2020

Bufferbloat with Comcast gigabit with Arris SB8200

With the working from home due to COVID-19, I decided it was finally time to upgrade my service.  I moved up to the gigabit plan (mostly for the extra upload bandwidth), and that also required a new modem, so bought an Arris SB8200.  It's DOCSIS 3.1, but is apparently synch'ing with my CMTS via DOCSIS 3.0, so these tests are with it in that mode.

I ran a couple raw wired performance tests, and saw the expected ~940Mbps download, but upload was seesawing all over the place.  Per, download latency was negligible, but the upload was up well over 200ms.

So I moved behind my home router (WRT1900AC running OpenWRT), and ran a set of tests with