My 30mb/s home internet connection gets saturated when downloading speeds over 5mb/s…

Discussion in 'Networking & Security' started by Gatecrasher3000, Sep 29, 2017.

  1. Gatecrasher3000

    Gatecrasher3000 Limp Gawd

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    So, I have a 30mb/s internet connection (confirmed with speedtest.net, and another site), but whenever Im downloading a file over 5mb/s (wired or wireless), on any system on my network, my internet gets completely saturated, and any other internet traffic comes to a grinding halt. My hardware is setup like this: Modem (Technicolor DPC3848V) > Wired/Wireless Router #1 (Asus RT-N66U) > Wired/Wireless Router #2 (Asus RT-N66U in AP mode), with about 3 wired devices, and 5 wireless, that are not all running at the same time. I usually use QbitTorrent to do large downloads, and I can see that that Im using 5-6mb/s, when I hit that point any other internet connection on my network is extremely slow.

    I know there a 1000 possible causes for this, but anything I should look at first?

    Thank you.
     
    Last edited: Sep 29, 2017
  2. boss6021

    boss6021 Limp Gawd

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    Sounds like confusion between 5MB and Mb.
     
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  3. Mackintire

    Mackintire 2[H]4U

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    Plug directly into the router Asus RT-N66U with an ethernet cable and disable any wireless on your testing device

    Run this: https://speedof.me/ download a jpeg (top right corner icon on the web page) and upload the jpeg image as a reply here.

    Part 2: http://testmy.net/ click on Extras --> Combined Speed Test and upload the results here as well

    Pictures tell a 1000 words.
     
  4. faxel

    faxel [H]Lite

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    5MB is about 50mb
     
  5. Vengance_01

    Vengance_01 [H]ardness Supreme

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    I usually use QbitTorrent to do large downloads, and I can see that that Im using 5-6mb/s, when I hit that point any other internet connection on my network is extremely slow.

    Thats your problem. You have way to many connections filling up your nat table or your are uploading near your max speeds. Try limiting your total number of allowed connections and or max upload speed in the BT client to about 80-85% of your max upload.
     
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  6. Biznatch

    Biznatch 2[H]4U

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    What is your upload speed and how much outbound traffic is there when this happens? TCP traffic will get destroyed if you saturate the outbound line and it can't send ACK packets.
     
  7. rtangwai

    rtangwai [H]ard|Gawd

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    Are you using stock firmware on the RT-N66U? If so flash it to DD-WRT, then set the IPtable from 4096 to 16,384 entries and timeout from 60min. to 90sec.

    It's not a bandwidth problem, it is an iptables overflow issue. I did the above to mine before I replaced it and my Internet connection never choked after that on a 50mb connection.

    Alternatively build a pfSense router - they don't use iptables at all. I built one for my gigabit Internet (that's why I retired the RT-66U) and it is 20% faster than the Bell router it comes with (using bridge mode to avoid doube-NAT).