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====== Networking - Buffer Bloat ======

See http://www.dslreports.com/speedtest

Ideally you want to see A to A+'s for bufferbloat.  

Test result showing a letter grade worse than a B, probably indicate you have bufferbloat.

That means the device at your bottleneck link (most likely your router) is letting bulk traffic (uploads/downloads) interfere with (and slow down) your time-sensitive traffic (gaming, Skype, Facetime, etc.)

If not then tune.

{{:networking:bufferbloat_-_results.png?800|}}

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===== Test for Bufferbloat =====

The [[http://dslreports.com/speedtest|DSL Reports Speed Test]] makes accurate measurements of the download and upload speeds along with the latency during the test.


1. Start a ping to google.com. You’ll see a series of lines, one per ping, typically with times in the 20-100 msec range.

2. Run a speed test simultaneously. To do this, start one of the speed test services below:

  * http://fast.com - (fast.com now tests for latency under load but we’d like more folk to check their results against our quick test)
  * http://speedtest.net
  * http://testmy.net
  * http://speedof.me
   
3. Watch the ping times while the speed test is running.  If the times jump up when uploading or downloading, then your router is probably bloated.

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===== Things To Do To Prevent Buffer Bloat =====

  * Change the Q size.

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===== References =====

https://www.youtube.com/watch?v=o8nL81DzTlU&t=380

http://www.dslreports.com/speedtest

https://community.flexradio.com/flexradio/topics/pfsense-router-tuning-v2-4-4

https://www.bufferbloat.net/projects/bloat/wiki/Tests_for_Bufferbloat/

https://forum.netgate.com/topic/112527/playing-with-fq_codel-in-2-4/815

https://forum.netgate.com/topic/112527/playing-with-fq_codel-in-2-4/856

https://forum.netgate.com/topic/112527/playing-with-fq_codel-in-2-4