This topic

Intermittent Drops in BT Fibre Broadband Connection

benalastair — Thu, 09 Jan 2025 08:43:32 GMT

Hi,

I’ve been experiencing intermittent drops with my BT Fibre broadband over the past few weeks. The connection will suddenly drop for 1-2 minutes and then reconnect on its own. This happens several times a day, disrupting my work and streaming.

Here are some details:

Router Model: BT Smart Hub 2
Connection Type: Fibre 100
Devices Affected: All devices (wired and wireless)
What I’ve Tried So Far:
- Restarting the router.
- Checking for loose cables.
- Performing a factory reset on the router.
- Running BT’s diagnostic tool (it shows no faults).
- Checking for service outages in my area (none reported).

The router’s lights show the connection is fine most of the time, but the drops still occur. Could this be an issue with line stability or noise on the fibre connection? Or should I request a replacement router?

Has anyone else experienced this, and are there any solutions I can try before contacting BT support?

Thanks in advance for your help!

Re: Intermittent Drops in BT Fibre Broadband Connection

Christopher_G — Fri, 10 Jan 2025 10:22:26 GMT

Hi @benalastair

There are a couple of other troubleshooting steps to try here. If you're still having a problem, I recommend speaking with our technical support team.

Chris

Re: Intermittent Drops in BT Fibre Broadband Connection

iniltous — Fri, 10 Jan 2025 10:52:36 GMT

Is your service FTTP ( so your router is connected to an ONT ) ?,

assuming it is FTTP , during your service dropouts what is the status of the ONT lights , does the PON light remain steady green or does the PON light go off ( or flash ) or does the LOS light ( loss of signal ) light come on ?.

How is your router connected to the ONT , directly ( basically the ONT and router are co-located in the same room and connected together by a short Ethernet cable ) or do you have an internal Ethernet network arrangement , typically provided by the developer in new builds , so the router can be in a different location to the ONT , the ONT ( in an under stairs cupboard for example ) is connected to one Ethernet socket and the router connected to a linked Ethernet socket in the living room …

Re: Intermittent Drops in BT Fibre Broadband Connection

Quesada — Sat, 11 Jan 2025 12:38:26 GMT

I have been experiencing a similar intermittent issue for 20 months. I had consistently been told that my problem was internal and was even persuaded to upgrade my “Full Fibre 900” package, to include “BT Halo 3”. Needless to say that this did not resolve the problem and BT have finally admitted, that there is a known software issue with the mechanisms that they employ, to measure the incoming signal to the ONT. This has been referred to as a “Stale PPP Session Fault”, which effectively means that “hereditary” and not “live” signals can sometimes be recorded. The bottom line is that their own remote tests and those carried out at the premises by “Openreach” engineers, are not as infallible as they claim, as they can result in “false positive” results. BT have consistently refused to accept the evidence supplied via the “MyBT App”, that my service has fallen below their “Stay Fast Guarantee”, on 259 separate days since April 2023. However, they will accept the results taken via the “https://pbtcsc.saas.nokia - Hub Smart Speed Test”, which you can request from customer support. The issue with this test is that it has a short shelf life of only 24 hours, so must be requested on a daily basis, which is time consuming. On a positive note from my perspective, BT have consistently implied that I am the only one of their 10+ million “Full Fibre” clients, who has experienced this issue, but this is clearly not the case. Good luck.

Re: Intermittent Drops in BT Fibre Broadband Connection

October — Mon, 13 Jan 2025 08:07:40 GMT

Hi, have you got anywhere with your issue as I'm experiencing very similar service issues.

my service has not been diagnosed as Stail nor have I been given the separate speed checker to test my line.

I too upgraded to the 900 halo service but the quality of connection remained very intermittent.

So I bought my own TP link router which has transformed the quality of the wifi around the home but when I notice poor issues just with general surfing let alone gaming and I do a speed test with 3 different apps they all show speeds way below the guaranteed std.

This has been going on since I changed to BT from EE which I never had any issues with.

Various engineers have OFF record told me the that some of the kit Inc the ONT is poor quality and they will be back at some point to replace it. Not very good to know but 10/10 for honesty.

The same problem with very low speeds occurred over the weekend.

Re: Intermittent Drops in BT Fibre Broadband Connection

Quesada — Mon, 13 Jan 2025 09:54:05 GMT

Hi. The simple answer is no. BT have effectively washed their hands of my complaint by placing it in "Deadlock", which meant that my only recourse was to complain to the Communication Ombudsman. However, it transpired that they are about as useful as a chocolate teapot. To be fair, it didn't help that BT failed to comply with my formal "DSAR", for three months, until after the Ombudsman had completed their investigation. However and on a positive note, I have noticed that over the last 20 months, this issue appears to have become much more widespread. It begs the question as to how much longer, BT can continue to argue that their external signal to the ONT is infallible, which is clearly untrue.

Re: Intermittent Drops in BT Fibre Broadband Connection

October — Mon, 13 Jan 2025 10:36:13 GMT

Yes that's my opinion of the situation.
Cheap equipment being installed and we have to put up with poor services.
The idea of buying EE due to the bad CS at bt is good but I hope EE manage to drag bt up to the next level. But at the moment it looks like it's going the same way as the Titanic.
I have nothing but praise for EE in both mobile and broadband I just hope it doesn't get ruined.

Re: Intermittent Drops in BT Fibre Broadband Connection

deenjames — Wed, 22 Jan 2025 08:21:56 GMT

@Christopher_Gwrote:
Hi @benalastair
There are a couple of other troubleshooting steps to try here. If you're still having a problem, I recommend speaking with our technical support team.
Chris

I’m also encountering this issue right now with my BT Fibre broadband. I have the same BT Smart Hub 2 and Fibre 100 connection, and the drops are just as frequent and disruptive. I've tried restarting the router, checking cables, and running diagnostics as well, but like you, I haven’t found a permanent solution yet.

It’s frustrating that the diagnostic tools don’t detect any faults while the issue persists. I’m wondering if this could be related to line stability or interference too. If anyone has resolved a similar problem, I’d appreciate hearing what worked for them!

Re: Intermittent Drops in BT Fibre Broadband Connection

October — Wed, 22 Jan 2025 08:56:03 GMT

I do think the service to our property is an intermittent issue, due to the service completely cutting out in the early hrs one morning.

Another phone call and we now have a new SH2.

Anyway we are getting our 900 ish to the ont at the moment.

Also by moving to a much more modern router the wifi is absolutely spot on we now have a choice of 2.4, 5 and 6ghz channels which we can separate and dictate which devices have priority etc.

This has come at a cost of over 350 for the equipment plus the monthly fibre contract which is expensive just for the fibre as the halo/4g part is now redundant.

Re: Intermittent Drops in BT Fibre Broadband Connection

Quesada — Thu, 29 May 2025 09:49:26 GMT

Is your service working normally now, or are you still having issues?

Re: Intermittent Drops in BT Fibre Broadband Connection

October — Thu, 29 May 2025 10:05:45 GMT

I am still experiencing drops in performance intermittently.

The wifi part of the system,since buying my own equipment has been great.

But im paying out a lot of money for a package that can't deliver due to the poor 4g signal. So their equipment is just cluttering up my spare room

So I'll just have to bide my time then I can sack BT permanently. Pathetic service overall.

Re: Intermittent Drops in BT Fibre Broadband Connection

Gadgetboarder — Fri, 04 Jul 2025 15:30:04 GMT

Hi All,

I have been having similar problems.
I hope this solution helps:

I was using BT fibre 900 with a super hub for awhile and then started seeing some connection issues after talking to BT and having some engineers visit it was suggested that I go to a super hub pro. This is what I did and it was stable for three months or so and in the past 3 to 4 weeks it has been dropping out regularly to the point where it would drop every minute or two for anything between five seconds to 2 minutes.

Long story short I had four internal engineer visits and two external engineer visits. I’ve spoken to numerous EE guides on the subject and to be fair to everyone they have tried their absolute best to solve the issue. When the engineers come for the internal inspection everything looks fine. There is an out bit of Wi-Fi congestion which shouldn’t happen as I only have 12 devices on the one gigabyte connection. The root of light is rock solid blue with no loss of signal the ONT has all three green lights on. The PON light is always on and I never have the LOS loss of signal light on Red at all but both Wi-Fi and wired connections dropout all the time .

The penultimate open reach engineer change the ONT for another one I believe it was a Nokia ONT. After having this programmed it, it was still dropping out he’s lying. Test was perfect for two green lights and the speed coming in or the signal test they do was at 15, which is perfect. The hub always showed Wan gigabit connection WAN coming in.

The guides were at a loss of what to do next and I was certain, as an electrical/electronic engineer of 34 years, that it was some sort of software issue.

The final open reach engineer came out and I explained to him what had happened and what equipment we’ve been through. It had had a new ONT and three different hubs nothing solve the issue. He spoke to one of his friends who was a fibre man for nine years and he suggested going into a nokia 2 ONT.

he did this after much conversation with the first line technical support for Openreach who are based in India and run through the standard script about changing the ONT resetting the router checking all the signals are coming in okay with the greenlight test and the speed coming in. He finally got through to the second line Support and while he was talking to them I noticed that the WAN speed Into the router was showing 2.44 Gb/ second.

We discussed that with the Support engineer and she wasn’t sure what was going on.

we discussed that with the Support engineer and she wasn’t sure what was going on.

After five hoursOf chopping and changing equipment and being on hold with the various technical support levels he tried to run his test on the network but it kept flagging upThat my router had negotiated a low speed than the ONT expected and wouldn’t let him close the job.

that my router had negotiated a low speed than the ONT expected and wouldn’t let him close the job.

I did ask if this was something to do With the speed coming into the hub not matching the service it should be one gig per second And not 2.44.

At this point the Internet both wired and wireless was stable, thinking our solve the problem, He put the original ONT back and the hub Showed one gig WAN Again.

again.

Then the Internet dropped out immediately and was back to the old situation I’ve intermittent drops every minute or two. What we had to do then was run the test he needed to run with the original ONT in place To complete his test to allow him to close the job then the lady on the second line Support reprogrammed the Nokia 2 ONT.

This is how the system was left with the Nokia 2 ONT Installed to the hub and it has been solid connection for two days now. I was getting 20 to 30 dropouts every hour previously.

installed to the hub and it has been solid connection for two days now. I was getting 20 to 30 dropouts every hour previously.

If ever an engineer comes to test the line again, it will throw a communication saying there’s a discrepancy between ONT and speeds but ultimately this solve the problem.

Personally I think the ONT was the fault even though all lights were green hub was fine. It seemed like it couldn’t handle the speed at the super pro was pulling and kept dropping the connection momentarily for it to come back seconds or minutes later.

personally, I think the ONT was the fault even though all lights were green hub was fine. It seemed like it couldn’t handle the speed at the super pro was pulling and kept dropping the connection momentarily for it to come back seconds or minutes later.

The ONT2 is a faster unit that doesn’t seem to suffer the same issue and he was able to report this back to his second line team and also other fibre engineers in his area because none of them have seen this before so hopefully that learning get shared as well.

I have a follow-up call tomorrow with the EE guide so I will inform him of what has happened in the hope that he learn from this and actually do some investigation as to what’s going on between the interfaces of the ONT and the hub that seem to mis-handshake the connection.

hopefully this has solved my issue and maybe have used to anyone reading this and if anyone from EE or BT can read this and feed it back into the company in some form of knowledge base so that we don’t all have the frustrations of having engineer after engineer come out to work on their demarcated part of the system where an overall picture is required. There’s obviously a speed issue between devices that is more common than his thought but none of the tests show any faults anywhere anywhere in the system be that exchange fibre line ONT or hub there needs to be entering accountability at some point.

Fingers crossed this helps

Re: Intermittent Drops in BT Fibre Broadband Connection

iniltous — Fri, 04 Jul 2025 16:15:02 GMT

I suspect some measurements are getting mis interpreted here ….a GPON system is 2.4Gb download and 1.2Gb upload , that’s the aggregate bandwidth, the way a PON works is all ‘data’ is download data is broadcast to all users simultaneously , so if your neighbours are watching Netflix, and you are watching Amazon Prime , your data arrives at next doors ONT as well as your OBT and their data arrives at your ONT as well as their ONT (times that by upto 30 users download data ) , effectively your ONT only responds to the data addressed to you and ignores everyone else’s data , the same for next doors, their ONT is only interested in their data ,not yours or anyone else’s on the PON .. that’s how Ethernet works ….if you buy a 1Gb profile the ONT limits the rate you receive to that , if next door are on 150Mb their ONT limits their port speed to the appropriate rate but the headend pushes the data out at 2.4Gb max and you see that rate before the ONT , that’s why your 1Gb service has a guaranteed speed much lower than 1Gb , if there were 30 customers all intensively downloading and all on 1Gb services , 2400Mb /30 =80 Mb , but statistically that not going to happen plus apart from speed tests download data isn’t consumed in a consistent manner, that how 30 customer on a PON can get the speeds they pay for .

I suspect the 2.4Gb you saw was the aggregate download GPON speed before the port speed limit was applied to your individual service by the headend telling your ONT , you are a 1Gb customer , seeing 2.4Gb is too coincidental not to be the total headend download speed , not your individual port speed set by your ONT

Re: Intermittent Drops in BT Fibre Broadband Connection

Gadgetboarder — Fri, 04 Jul 2025 16:35:40 GMT

Hi , nit sure if this was a reply to me as i didn't understand the content as there were acronyms s i don’t understand, but i have some screen shots of the hub before and after ONT’s if that helps as were were changing them and also the test result cro. The open reach engineers test thats shows the speed mismatch. I cant post that as a phot as it won’t let me drop the size anymore and its too big as a phot so here the text.

it was failing i mediately not after the 5 - 10 minute usul test he told me:

Here are the results of your FTTP test request for OGEA80547872

usingFastTest+.

The outcome was Customers router has negotiated with the

ONT at a lower speed than product. This is either a issue with the router or cable. Please reset the router and retest if the problem is not resolved then replace the Ethernet cable. Please check the connection quality between ONT and Router.

The date and time we processed

thats all i got from photographing his phone, but you get the gist.

Re: Intermittent Drops in BT Fibre Broadband Connection

iniltous — Fri, 04 Jul 2025 19:30:30 GMT

Presumably you have an EE router as the user interface doesn’t look like the BT one .

OR usual OBT are rated at 1Gb , some new speed profiles on offer from EE (BT don’t offer it ) are 1.6Gb , and they require an ONT swap from 1Gb to a 2.5Gb rated ONT as the 1Gb one isn’t compatible with the increased speed ….once a 2.5Gb ONT is fitted , it’s backwards compatible if the customer downgraded to speeds of 1Gb or less ,

The router shows a 2.5Gb WAN link initially, presumably your ONT is the latest 2.5Gb version ( check what version of ONT is fitted ) why the link speed then reduces to 1Gb may be a problem with the negotiation between headend and ONT , or it could be because you are only on a 1Gb service , having said that , someone on 500Mb the link speed shows 1Gb on 1Gb ONT’s .

Not all Ethernet cables are the same standard , if the ONT were connected to the router with an vet old Ethernet cable , it may only capable of 100Mb , or if a faulty cable is used then the link may not work at the design speed but a lower speed , hence the comment

If you are not on the 1.6Gb profile but have a 2.5Gb ONT , that should be OK but I’d ask to be put on a 1Gb ONT so there is no compatibility issues between the ONT and headend .

Re: Intermittent Drops in BT Fibre Broadband Connection

Gadgetboarder — Fri, 04 Jul 2025 20:57:47 GMT

Thank you for all that info but most of it is over my head. I just know that my internet is now working when it was dropping 20-30 times an hour. So i’m not changing anything now. We have changed hubs, ONT’s, cables etc. and this is what we found to work.

The 1gb ONT just didn’t work as we did an ABA back to back test.

i was only offering all this info incase anyone else is stuck as it may give options because the issue took weeks to resolve.

thank you for your input. The issue with BT/EE (to me they are the same just rebranded) is that no-one has that complete end to end responsibility and it is the interfaces between responsibilities where I believe the problem lies.

Re: Intermittent Drops in BT Fibre Broadband Connection

Quesada — Sat, 05 Jul 2025 07:54:15 GMT

I have been having the same issue for almost 2 years now, but will soon be able to leave without penalty.

Re: Intermittent Drops in BT Fibre Broadband Connection

Quesada — Sat, 05 Jul 2025 08:07:27 GMT

This is spooky because I have been having intermittent drops in connection for almost 2 years now. Back in November 2023, the fault actually occurred during an Openreach engineers visit and whilst I was on my mobile, talking to a remote BT technician. Although the technician advised the engineer to upgrade the ONT, it transpired that after almost 2 hours, he could not obtain authority from his superiors at Openreach. Apparently it boiled down to who would forfeit the costs. The Hub was exchanged during the next engineers visit, (there have been 13 so far), but with a like for like model. You couldn't make it up.