A red LOS light on a Frogfoot ONT means the optical signal from the fibre network is not reaching your device. This usually indicates a line fault, fibre break, or access-layer outage. If LOS remains red after proper power cycling and cable checks, escalation to the FNO is required.
What the Problem Means
If your Frogfoot ONT shows a red LOS (Loss of Signal) light, the ONT is not detecting optical light from the fibre distribution network. This is an access-layer signal issue, not a router, WiFi, or gaming performance problem. A persistent red LOS means the ONT cannot establish a physical optical link to the exchange.
In South Africa, fibre infrastructure is split between three responsible parties:
- The User — power, patch lead, internal setup
- The ISP — authentication, provisioning
- The FNO (Frogfoot) — physical fibre line and signal
A red LOS almost always indicates a break or signal interruption between your home and the Frogfoot distribution point.
Why It Happens
Common causes on Frogfoot infrastructure:
- Fibre break between home and street cabinet
- Damaged or bent fibre patch lead
- Loose connector at ONT
- Area maintenance or outage
- Power instability affecting ONT boot sequence
If the PON light is off and LOS is red, the ONT is not registered to the network because no optical signal is detected.
Frogfoot ONT Light Meaning Table
| Light | State | Meaning | Action Required |
|---|---|---|---|
| Power | Off | No power | Check power source |
| Power | Green | Device powered | Continue checks |
| PON | Flashing | Attempting registration | Wait 2–5 minutes |
| PON | Solid Green | Registered to network | Signal OK |
| LOS | Red (Solid/Flashing) | Optical signal lost | Diagnose fibre path |
| LAN | Flashing/Green | Router connected | Not a fibre signal fault |
If LOS remains red beyond 5 minutes after restart, the issue is not a temporary sync delay.
Step-by-Step Fix
Confirm Stable Power
- Ensure ONT adapter is firmly plugged in.
- If using a UPS during loadshedding, confirm output is stable.
Inspect Fibre Patch Lead
- No tight bends.
- No visible damage.
- Fully inserted into ONT.
- Avoid unplugging unless necessary.
Power Cycle Correctly
- Switch OFF ONT.
- Wait 2 full minutes.
- Switch ON.
- Allow 5 minutes for sync attempt.
Observe Boot Sequence
- Power solid.
- PON blinking.
- PON solid.
- LOS off.
- If LOS turns red and stays red, signal is not reaching the ONT.
Check With Neighbours
- If multiple Frogfoot users nearby are offline, it is likely an area-level outage.
If all steps fail, escalation is required. The ISP cannot repair physical fibre infrastructure — Frogfoot must restore signal at the access layer.
Definition: LOS and PON (Access Layer Context)
The physical fibre segment between your property and the fibre distribution network.
Indicates no detectable optical light is reaching the ONT.
If LOS is active, authentication cannot occur because signal transmission has failed before network registration.
When to Escalate
Escalate to your ISP when:
- LOS remains red after proper restart
- Patch lead is intact
- No internal cable damage
- Neighbours report similar outage
In South Africa, Frogfoot repair timelines typically range from 24–48 hours for minor faults and up to 72 hours for fibre breaks or cabinet damage.
If a fibre break is detected at the street level, this requires FNO technician dispatch. The ISP cannot repair physical fibre infrastructure.
Responsibility Breakdown
| Layer | Responsible Party |
|---|---|
| ONT power & patch lead | User |
| Authentication & support ticket | ISP |
| Fibre line & street cabinet | Frogfoot (FNO) |
Understanding this prevents unnecessary router resets or WiFi troubleshooting.
When This Is NOT the Issue
If all of the following are true:
- PON is solid green
- LOS is off
- Internet connects but drops intermittently
Then the issue is not optical signal loss.
See our fibre diagnostic guides