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Re: slow bandwidth


Slow Bandwidth via iPerf Test


Can anybody help explain why http://speedtest.att.com/speedtest/ shows that I'm getting 43.07 Mbps down and 5.20 Mbps up, but an IPERF test only shows that I'm getting 5.47 Mbps both up and down?




att speedtest.pngatt RG.pngatt iperf.png

Tags (3)
Message 1 of 18

Re: slow bandwidth

Agreed.  I get pretty much the same results when doing testing directly on the computer though.  Teamviewer doesn't appear to have much overhead.  I've tested this on a couple of computers, all wired, and all with the same results.

Message 16 of 18
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Accepted by bcothren
‎12-03-2015 2:58 PM

Re: slow bandwidth

I finally got it figured out.


By default, iPerf sends to the server.  So my 5.5 Mbps throughput was only my upload speed.  When I ran iPerf in reverse mode (-R) is downloads from the server.  I wasn't getting good results from a single TCP session, but when I increased it to 10, i was getting the results I was expecting (47 Mbps).  If you want to try these tests for yourself you can use these commands for any public iPerf server:


*Case sensitive

Upload test      - iperf3 -c iperf.he.net

Download test  - iperf3 -R -c iperf.he.net -P10


I do not know what the bandwidth limitation is with this iPerf server

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Message 17 of 18

bandwidth troubles???

I recently upgraded to the highest speed that att has but continue to have troubles using my fax machine and a securuty camera....It was working great after the upgrade now my fax only passes the test number if I disconnect my security camera,,, somehowe something has gone wrong interesting enough it works the minute i call att then doesn't the minute I get off the phone wierd makes you suspect they don't want me faxing ha ha the fax just says communication problem or receient busy .Am I crazy or should my band width needs be totally taken care of with the 24 Mbps I am supposed to be getting earlier today My speed on a speed test sayis under 18Mbps after talking to att and them adjusting my modem????I now have around what I should have 24 Mbps so what's up here?

Message 18 of 18
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