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Networks LAN cripples ADSL/Internet on new router

Discussion in 'Tech Support' started by LDJ, 30 Jan 2012.

  1. LDJ

    LDJ What's a Dremel?

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    I recently switched from the stock O2 router to a new TP-Link router due to constant crashes, disconnects and general poor ADSL performance. Since doing so my ADSL connection has been much better and even sync's faster than with the O2 router but now I've noticed a problem with LAN traffic.

    When I'm copying files over the network, from my main PC to HTPC (connected via 85Mb homeplugs), my ADSL connection grinds to a halt on the machine that is doing the copy. Its almost as if the LAN traffic is taking precedence over the ADSL and thus data cannot get through from the web until the LAN copy finishes. However, my homeplugs only achieve about 1.5Mb/s copying speed so there should be PLENTY of spare capacity through my gigabit connection in the router and on my PC.
    Loading a web page on the machine takes an age and stalls almost completely until the file copy is finished, which never used to happen on my previous O2 router.

    Has anyone seen this behaviour before or know if there is a setting to change that will prevent this? This TP-Link router has lots and lots of config settings, but I really do not know which setting it would be...

    Thanks
     
  2. moorsey

    moorsey What's a Dremel?

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    So just to confirm, PC is connected to router via gigabit and HTPC is connected to router via powerplug?

    I have seen this on one of my servers that runs over powerplug, if doing a copy, it maxes out the connection and Internet doesn't perform, which is understandable.
     
  3. LDJ

    LDJ What's a Dremel?

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    yep, thats correct.
    When I used my o2 router in the exact same config I had no such problems, so its a router issue. I just dont know what setting(s) this could be linked to....
     
  4. Cleggmeister

    Cleggmeister Of reasonable knowledge...

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    I can't suggest what's causing the issue but I would recommend buying a dedicated GB switch and using this rather than the router LAN ports.
     
  5. LDJ

    LDJ What's a Dremel?

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    I'm not really keen on adding another plug and another power sucking device though. I dont understand why its doing this when there is plenty of spare capacity 'in the pipes'.

    I was hoping there would be some way to prioritise WAN traffic over LAN traffic on the router somehow?
     
  6. Atomic

    Atomic Gerwaff

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    That's most likely your issue there. HomePlugs aren't an 85mb connection, that's a maximum connection speed. What you have get depends on the mains wiring and interference caused by other electrical devices you have plugged in.

    There isn't plenty of spare capacity as you don't have a gigabit connection at either end. If you're going through HomePlugs - they are the bottleneck in your network.

    So as you're only getting 1.5Mb/s during a file transfer you aren't getting the full speed and the copy process is most likely saturating the connection.

    Unless the router supports QoS there's no easy way to do what you want.
     
  7. saspro

    saspro IT monkey

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    Don't forget that cheap routers cannot run all the ports at wire speed.
    In order to run at wire speed you need proper networking kit.
     
  8. LDJ

    LDJ What's a Dremel?

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    Yeah, so my Gigabit PC talks to my homepug htpc via a gigabit router, which l thought meant the gigabit PC still has plenty of spare capacity to do other things (like transfer files to other machines or browse the web), but instead it grinds to a halt.
    Its not a capacity issue as if I swap my old O2 router back in it works as I would expect. That is, the PC sends data to the HTPC as fast as that can accept (over the homeplugs) and everything else goes on working with the extra capacity.

    The router does have QoS, but I dont really know what to configure to get LAN traffic deprioritised over WAN traffic
     
  9. LDJ

    LDJ What's a Dremel?

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    Maybe its just a hardware limitation then, which is a shame as this router is really good and has 5* reviews on Amazon & has given fantastic performance compared to my old router.
     
  10. saspro

    saspro IT monkey

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    I'd just put a switch in then so the router doesn't have to deal with all the extra traffic.
    A small 5 port job won't take more than a couple of watts to work.

    I'd also seriously consider running some Cat 5 so you can get much faster transfers.
     
  11. Atomic

    Atomic Gerwaff

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    PC <- Cat5? -> Router <- Homeplugs-> HTPC?

    Then you've solved your issue! The router can't handle the traffic you're throwing at it.
     
  12. LDJ

    LDJ What's a Dremel?

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    Yep, thats it :)

    A router that cannot handle > 2Mb/s? :confused:
     
  13. Atomic

    Atomic Gerwaff

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    Seems to fail at routing data from different sources to a single device from what you've said.
     
  14. specofdust

    specofdust Banned

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    Check that your LAN and wireless router aren't running on the same IP address. If the two networks are discrete, then you might have a conflict there.
     
  15. Booti

    Booti Minimodder

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    Have you checked that your PC and HTPC both have their NIC cards configured correctly. Check they are set for the right speed for the network and full duplex.
    Next try the HTPC directly onto the router, so as to rule out the HomePlugs.

    If its still failing at that point, it woukd seem to be a throughput issue with the new router.
     
  16. RichCreedy

    RichCreedy Hey What Who

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    might be worth turning off QOS, it's probably prioritising local traffic
     
  17. LDJ

    LDJ What's a Dremel?

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    QoS is currently disabled. TBH I wouldn't know what to set to enable it as the first thing it asks is to "Select Default DSCP Mark" :confused:
     
  18. LDJ

    LDJ What's a Dremel?

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    I dont see anywhere on this router that you can differentiate the two. there is only one IP address config that I can see...
     
  19. LDJ

    LDJ What's a Dremel?

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    Whats odd is that since posting, I've upgraded from Win7 to Win8:CP and its made no difference whatsoever, so doubt it's a NIC issue is it?
     
  20. LDJ

    LDJ What's a Dremel?

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    OK, so I bought a 5-port switch thinking this would solve the problem, connected the router, PC and HTPC (via Homeplug) directly to the router and left the rest of the configuration the same.

    No difference. LAN traffic still completely kills the internet on this machine. In fact, if I'm coping a file over the LAN (at 2MB/s), I can't even access the router config page until the transfer has finished!

    All machines still have a default gateway of the router, is that the issue? Changing that though will kill my internet access, so not sure what should be changed here?
     

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