Category Archives: Networking

CeroWrt 3.10.50-1 Field Report

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Comments on the CeroWrt 3.10.50-1 build that I installed on my WNDR3700v2 primary router:

  • Seemed to install and configure properly (I retrieved the updated version with the lighthttpd fix)

  • I used a local copy of config-cerowrt.sh (from https://github.com/richb-hanover/CeroWrtScripts#config-cerowrtsh) to configure the router to have my own DSL user/pw, SSID names, etc.

  • mDNS seems to work across subnets. (I don’t think that it worked properly for the last few CeroWrt releases)

  • The first time I looked, /usr/lib/CeroWrtScripts didn’t seem to have been updated with the latest from github.com (see link above). But I looked again (after a reboot, and running the config-cerowrt.sh script, and another reboot (maybe something else)), and the script matches the github version… Not sure how that could have happened.

  • Debloating seems to be working as expected. netperf-wrapper with RRUL shows a jump from 60 to 80 msec (normal on my 7mbps/768kbps DSL link). Here’s the plot:

speedof.me

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Doc Searls mentioned in passing that he uses a new speed test website. I checked it out, and it was very cool…

www.speedof.me is an all-HTML5 website that seems to make accurate measurements of the up and download speeds of your internet connection. It’s also very attractive, and the real-time plots of the speed show interesting info. (See below.)

Now if we could get them to include a latency measurement so people could point out their bufferbloated equipment.

New CeroWrt Router scripts

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I posted a set of scripts that people can use to test, configure and debug their CeroWrt router installations. CeroWrt router firmware is a test bed for learning about and eliminating bufferbloat.

The scripts are available on Github at https://github.com/richb-hanover/CeroWrtScripts. They include:

  • betterspeedtest.sh – a script that emulates the famous (but limited) speedtest.net. This script is better because it measures ping latency during the download and upload, and tells you how bad (or not) the bloat is in your network/router.

  • netperfrunner.sh – a script that emulates the RRUL test suite. It runs on the CeroWrt router (or your laptop) to measure the latency under heavy load.

  • config-cerowrt.sh and tunnelbroker.sh – two scripts for configuring a CeroWrt router to a consistent state after flashing new firmware.

  • cerostats.sh – a script that collects a number of configuration and operational stats that is useful for debugging.

RRUL Tests – CeroWrt 3.10.28-14

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RRUL charts

[Note: This is an earlier result. Check out the subsequent posting for CeroWrt 3.10.28-16 (above)]

The postings below are a series of charts that were created by the netperf-wrapper program. Note: I don’t know why the upload charts show such fragmentary data.

All charts made with default Queue Discipline: fq_codel, simple.qos script, ingress ECN on, egress ECN off. Variations are primarily with the Link Layer method.

DSL Modem has sync rate of 7616kbps down/864kbps up.

Chart names have the form: Down-Up-dflt-link-try.png where:

  • Down is the entered download speed (kbps)
  • Up is the entered upload speed (kbps)
  • Dflt is the default Queue Discipline as described above
  • Link is None or ATM with the number of overhead bytes [0 | 44]
  • try is an optional second or third attempt

Click on an image to view the entire set in a gallery