Troubleshooting VDSL2 for Speed Issues

This article will guide you through the troubleshooting for speed issues on an iiNet VDSL2 service.

Select one of the links below to jump to a query:

  • When running a speed test on an Ethernet cable-connected computer, your results are significantly slower than usual
  • These slow speeds occur on all connected computers/devices, not just one
  • Files take a long time to download despite being small in size
Potential cause
Try this:
WiFi Channel Congestion If you're close to a number of other WiFi networks (e.g. an apartment building), it's possible yours and your neighbour's modems may be connecting to the same WiFi channel, leading to slower speeds. You can change the WiFi channel in your modem to resolve the issue.
Weak WiFi signal To rule out a weak WiFi signal, you should test your speed on a computer connected to your modem with an Ethernet cable.
Damaged or loose cables Check that all cables are in good condition and plugged in securely.
Virus or malware infection Run an antivirus/anti-malware scan using your antivirus software. If you need a hand with this, please contact your security software’s Customer Support.
Firewalls or other antivirus software settings Test your speed while firewalls/antivirus software is temporarily disabled. Please contact your security software’s Customer Support if you need a hand with this.
Data congestion To rule out data congestion, reduce the number of connected devices on your home network.
Network congestion Test your speed at different times of the day, especially if your slow speeds only seem to occur around 5-8PM, which is a typical time for network congestion to occur.


  1. Firstly, you should check the 'sync speed' in your modem settings. 'Sync speed' is the speed at which your modem is synchronising with the VDSL2 network.
    This article covers how to do this on an iiNet VDSL Home Gateway (Huawei HG658), our default modem supplied for VDSL2. If you purchased a VDSL2-ready modem elsewhere, please switch to your iiNet VDSL Home Gateway for troubleshooting.

    On a computer that's connected to your VDSL Home Gateway (be careful not to confuse this with an additional router used for WiFi) open your web browser and go to Log in with the default username "admin" and default password "admin". If you have changed the login details from the defaults, use your custom login details instead.

    Next, click Status in the left-hand column and then select WAN. Click the DSL Information tab. In the Line Status table, the speed listed next to "Downstream line rate (kbit/s)" is your sync speed for downloads.


  2. If your sync rate is poor, please please call us on 13 22 58 for further assistance.

    If your modem has a good sync speed but your speed test results on connected computers are significantly slower, continue to the next step to troubleshoot potential interference on your home network.

  3. Unplug all devices from every telephony/networking wall socket at your address, including modems, phones, pay TV boxes and EFTPOS terminals.
  4. Plug your modem directly into the wall socket used for VDSL2 broadband (no line filter/splitter should be used for modem connections). This is known as “isolating” your modem, because it is now the only thing plugged in.
  5. Connect one computer to your modem with an Ethernet cable. If you have any other computers cable-connected to your modem, unplug their Ethernet cables.
    Note: There are different kinds of Ethernet cables. We recommend using a Cat 6 or Cat 5e cable. While a Cat 5 cable will work, it may not support the speeds of your VDSL2 service.
  6. Turn off or disconnect any computers or devices connected to your WiFi network. Alternatively, the iiNet VDSL Home Gateway modem has a WLAN button on the back which you can use to temporarily turn WiFi broadcasting off. Simply press the button again to turn WiFi back on after troubleshooting is complete.

  7. Run a speed test. If your speeds are faster now, follow the advice below.
  8. If your speeds are still slow, if possible, try using different phone cable to plug your modem into the phone socket, and a different Ethernet cable to plug your computer into your modem.
  9. Run another speed test. If your speeds are faster now, follow the advice below.
  10. If possible, plug in a different VDSL2-ready modem at your property and run another speed test. If another modem doesn't give you poor speeds, the original modem may be faulty.
    If a different VDSL2-ready modem also gives you slow speeds, then it's safe to say that the original modem isn't faulty.
  11. If you continue to experience slow speeds, please call us on 13 22 58 for further assistance. 


  1. If your speed improves while your modem is plugged straight into the wall socket, that means that one of the other pieces of equipment you had plugged in (e.g. filter, cable, phone) was interfering with your home network.
  2. Ideally, you should plug in one device at a time and test your speed again before plugging in another device. This will help you identify any specific hardware that may be causing speed issues.
  3. If your speed drops again, the device you’ve plugged in is probably faulty or affecting your connection; or its cable may be damaged.
  4. We recommend replacing a cable or device if it is faulty. Remember that line filters should not be used when plugging in your modem.
  5. If you have more than one wall socket in your home, it's also possible that internal wiring issues are causing connection intereference. If you suspect this is the case (i.e. speeds drop once devices are plugged into a different wall socket, and changing devices does not resolve the issue) please contact an electrician who is registered with an ACMA-accredited registrar. This means that they are properly licensed to work on communications cables.


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