Troubleshooting iiNet FTTB for Speed Issues

This article will guide you through the troubleshooting for speed issues on an iiNet Fibre to the Building (FTTB) 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:
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 iiNet modem settings (remember, you must use the modem supplied by iiNet for your FTTB connection). 'Sync speed' is the speed at which your modem is synchronising with the FTTB network. See advice below for the TG-789 Broadband Gateway and the TP-Link VR1600v.
    TG-789 Broadband Gateway

    On a computer that's connected to your TG-789 Broadband Gateway, open your web browser and go to After logging in, click the Broadband panel and then click + Show advanced options in the upper right-hand corner. Scroll down to Line rate - the speed listed next to the downwards arrow is your sync speed for downloads.

    TP-Link VR1600v
    On a computer that's connected to your TP-Link VR1600v, open your web browser and go to After logging in, click the Advanced tab and you should see the Status page. Scroll down to the DSL section and check the table - the speed listed for Current Rate (kbps) - Downstream is your sync speed for downloads. You can search "kbps to mbps" in Google for a handy tool to convert this kbps data transfer rate to Mbps.


  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. Ensure that your modem is plugged directly into the wall socket (or if you have an NTU, directly to the NTU's GATEWAY port). No line filters/splitters should be used with FTTB.
  4. Using an Ethernet cable, connect a computer directly to a LAN port on your modem. 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 FTTB service.
  5. Turn off or disconnect any computers or devices connected to your WiFi network. Alternatively, press the Wireless button on your TG-789 modem to temporarily disable your WiFi network (note that you'll need to press this button again later to turn WiFi broadcasting back on).
  6. Run a speed test. If your speeds are faster now, then the issue may be related to data congestion where too many devices are using the connection simultaneously, affecting performance.
  7. If your speeds are still slow, if possible, try using different phone cable to connect your modem to the phone socket (or if you have an NTU, to the NTU's GATEWAY port). An old or damaged cable may be interfering with the connection.
  8. Run another speed test. If you continue to experience slow speeds, please call us on 13 22 58 for further assistance.