Testing fibre: what to know
Fibre to the home (FTTH) brings an optical fibre all the way into your home. Unlike ADSL, speed hardly depends on distance from the exchange: a 200 Mbps plan should give close to 200 Mbps over an Ethernet cable. Home fibre plans now commonly reach 1 Gbps, and multi-gigabit plans (2, 5 or 10 Gbps) are spreading.
To understand how the signal reaches you (OLT, splitter, distribution point, ONT), read how FTTH fibre works.
Expected results by plan
| Fibre plan | Expected over cable | Typical over 5 GHz Wi-Fi |
|---|---|---|
| 50 Mbps | 45 to 50 Mbps | 35 to 50 Mbps |
| 100 Mbps | 90 to 100 Mbps | 60 to 95 Mbps |
| 200 Mbps | 180 to 200 Mbps | 100 to 180 Mbps |
| 500 Mbps | 450 to 500 Mbps | 200 to 400 Mbps |
| 1 Gbps | 850 to 940 Mbps | 300 to 700 Mbps |
Around 940 Mbps on a 1 Gbps plan is normal: it is the practical limit of a gigabit Ethernet port once network headers are taken into account.
Slow fibre: the usual causes
- Wi-Fi: the number one cause. A phone two rooms away rarely exceeds 150 Mbps. See fibre slow on Wi-Fi, fast on cable.
- Cable or port: an old Cat 5 cable or a 100 Mbps port caps everything at about 94 Mbps.
- Computer: an old network card, or antivirus software inspecting traffic.
- Red LOS light: the optical signal is lost, see red LOS light on a fibre router.
- Evening congestion: if speed always drops at the same hours, read why speed drops in the evening.
Measure your connection now. Start the test
Recommended test procedure
- Connect a computer to the router with a Cat 5e or Cat 6 Ethernet cable.
- Temporarily disconnect other devices from Wi-Fi.
- Run three tests a few minutes apart and keep the middle value.
- Test again over 5 GHz Wi-Fi near the router to see how much wireless costs you.
- If cable speed stays below 70% of your plan, keep screenshots of several tests and send them to your provider's support.
Frequently asked questions
Why can't I reach 1 Gbps over Wi-Fi?
Even with Wi-Fi 6, a phone rarely exceeds 500 to 700 Mbps in real conditions. To measure 1 Gbps you need a computer with a gigabit port on a cable.
Does fibre have better ping than ADSL?
Usually yes. Fibre gives lower and more stable ping than ADSL and 4G, which helps gaming and video calls.
My fibre upload is much lower than download, is that normal?
It depends on the plan. Some fibre plans are asymmetric. Check the upload speed in your contract.
