Codel on Cerowrt-3.3.6-2

Posted on May 14, 2012 by Dave Täht.

A test release of CeroWrt is now available that has support for Kathie Nichols’ and Van Jacobson’s new AQM, Codel , and Eric Dumazet’s new fair queuing implementation on top of that, fq_codel.

fq_codel is enabled on all interfaces by default. It is vastly simpler than what we were using before (sfqred) and draws upon and improves on the same body of ideas (head drop, fq, timestamping) but now tied to Kathie and Van’s blinding insights as to a good drop strategy, and Eric’s successor ideas as towards head of queue behavior and cache line optimizations.

There is a script that can be set to your uplink and downlink speeds, but no uci interface for it as yet, nor gui. (help on finishing aqm-scripts and the luci interface gladly accepted)

To see all the chocolately goodness of what fq_codel can do to wired and wireless latency, it would be good for more to play with it.

Benchmarks have been very good thus far, and more benchmarks and analysis are highly desired.


This release suffers from an unrelated bug ( #379 ) and should NOT be installed as your main router. I would love to beat this bug because it’s the only prio 1 remaining but thus far, no luck. Under lighter loads CeroWrt appears to work just fine, but that’s for me. YMMV.

Get it here:

RSS feed

Recent News & Articles

Mar 21, 2019 Wiki page
Dave Taht's Take on TCP
Mar 17, 2019 Wiki page
Jake Holland's Stance on ECN
Sep 6, 2018 Wiki page
Pete Heist's Thoughts on ECN
Sep 5, 2018 Wiki page
Dave Taht's Stance on ECN
Sep 4, 2018 Wiki page
Jonathan Morton's Take on ECN

Find us elsewhere

Bufferbloat Mailing Lists
#bufferbloat on Twitter
Google+ group
Archived Bufferbloat pages from the Wayback Machine


Comcast Research Innovation Fund
Nlnet Foundation
Shuttleworth Foundation

Bufferbloat Related Projects

Congestion Control Blog
Lede Project (OpenWrt)
Flent Network Test Suite
The Cake shaper

Network Performance Related Resources

Jim Gettys' Blog - The chairman of the Fjord
Toke's Blog - Karlstad University's work on bloat
Voip Users Conference - Weekly Videoconference mostly about voip
Candelatech - A wifi testing company that "gets it".