Intermittent but regular LOS Red light on ONT

[BrigadierA]

Wondering if anyone else has ever had this same issue with BT FTTP?

I was on BT FTTP 300mbps for over a year without any problems. Upgraded recently to BT FTTP 500mbps. I've had a few days in the past week where I lose internet (LOS red light on the ONT). This always starts around 12.30 to 1pm in the afternoon. The outage will be for 8 minutes and then the internet reconnects itself. It will then repeat this through the afternoon at regular intervals. Today it has happened every 49 minutes, yesterday it was every 30 minutes. In the evening it will eventually get longer between outages until it is fine again. I have an Openreach engineer coming tomorrow morning, but worried they aren't going to find the problem as it's intermittent. I tried switching off the power to the ONT and Hub as directed by support, but the made no difference.

Any ideas?

[stevebrass]

All a bit odd. The change of package doesn't require any change of cabling etc. However, there could be a software glitch at the BT end.

Or coincidental to the package change, a fault has appeared on the cabling to your property or on the ONT.

Let's see what the engineer finds.

[Keith_Beddoe]

Low optical power input to the ONT, could be caused by many things, a bad splice, dirty optical connectors etc. Openreach should be able to measure the power input with an Optical Power Meter.

[BrigadierA · Accepted solution]

The Openreach engineer didn't come to the property in the end. I just received an everything should be resolved now text from BT. Was dubious as I'd had 2 texts saying the same thing in the past week and the problem had continued. Called support to check and they confirmed that Openreach had been out in the early hours and had rectified the problem remotely. I am happy to say that I've had a whole day without issues, so hopefully it's all good now.

Thank you for your thoughts on the problem. I was starting to worry that they would have to replace the cabling to the ONT which would have made a mess as it goes round 2 door frames!

[DavidM]

Thanks for getting back and letting us know this is sorted @BrigadierA .

Cheers

David