Troubleshooting FTTH for Speed Issues

This article will explain how to troubleshoot speed issues for an iiNet FTTH service such as OptiComm or RedTrain.

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. Locate your FTTH equipment - this will be a Connection Box. This is most commonly installed indoors on the inside of an outer wall of the premises, sometimes in the garage.

    Note: Some older installations may have the Connection Box in an outdoors cabinet on an exterior wall of the premises.

  2. Locate the Connection Box's power button or switch, turn it off for at least 60 seconds, and then then turn it on again. Once the Connection Box has finished booting up, run another speed test to see if the issue has been resolved by a simple reset.

    Note: If an outdoor Connection Box has no apparent power button or switch, skip this step.

  3. Using an Ethernet cable, connect a computer directly to the active LAN port on your Connection Box to rule out any loss of speed due to WiFi routers or WiFi signal issues.

    In most cases, the active port on your Connection Box will be LAN 1. If a different LAN port was activated when your FTTH equipment was installed, please use that one instead.

    Note: There are different kinds of Ethernet cables. For FTTH connections, we strongly recommend Cat 6 or Cat 5e. While a Cat 5 cable will work, it won't support the speeds of your FTTH service.

  4. If you have Hub or Smart wiring in your home and you get slow speeds when plugged into any port on your Hub/Smart panel but not when plugged directly into the Connection Box, then there may be an issue with the wiring between your Connection box and the Hub/Smart panel.
  5. Run a speed test using a different computer that is cable-connected to the active LAN port on your Connection Box. If a different computer gives you acceptable speeds but the first computer you tested doesn’t, then there may be performance issues with the first computer.
  6. If you continue to experience slow speeds, please call us on 13 22 58 for further assistance.