topic Re: NBI FTTP Slow between 8pm and 11pm in Broadband

NBI FTTP Slow between 8pm and 11pm

Tony012334 — Tue, 01 Sep 2026 18:05:52 GMT

Hi all. I think I already know what the issue is, and I'm sure you all do to. In August 2026 we moved from Starlink to Sky Ultrafast FTTP. The move was due to the NBI finally connecting our home. I thought I give the 1gig plan a go, but dont really require it. Only three of us in the house and we don't game. I have my own Ubiquiti gear and set that up and disconnected the sky hub after about day 3. I haven't really been paying attention to speeds, but almost every time I did a speed test directly from my router I was getting about 900-950 down and pretty much 110 up. I did notice on my ubiquiti dashboard that the latency would be consistant all day at about 6-7ms, then like clockwork from around 8-11 that might jump to 40-50ms. If I run a speed test during these times I can get anywhere from 30M - 50M - 200M speeds. I reconnected the Sky hub and don't mind the double NAT. Over the past week or so the results are the same. Extremely slow speeds at peak times, every day from 8-11pm. There is no other reason for this only congestion as I have done test with only one laptop WIRED to hub and everything else disconnected, no wireless clients. How can I have a 1gig connection that goes below 100M ..? Crazy. I have contacted sky and an engineer is due to call on Wednesday next. He may spot something, but I doubt it. This was happening with my ubiquiti hub, and also with SKY's own hub so we can rule hardware out. I know FTTP connections are split and there is a contention of about 30-1 but we all can't be hogging at exactly the same time? I wonder is the split much higher that 30-1. Anyway, I have signed up to Sky broadband for 1 year, however if this continues I will try to get comreg involved as this is Appaling? 1gig fibre getting sub 100M....poor. I don't think I ever saw Starlink drop below 200Meg and I know Sky is cheaper but seriously...???

Re: NBI FTTP Slow between 8pm and 11pm

Jen_out_of_Jen — Wed, 02 Sep 2026 09:21:04 GMT

Hi @Tony012334 , I’ve escalated your post to our Community Messaging team who will invite you to a private chat shortly and help you with this.

Just look out for the colourful bubble to start the conversation. Please be aware conversations automatically close if there is no response within 48 hours.

Here's more information on how Community Messaging works - https://helpforum.sky.com/t5/Did-you-know/Escalating-a-post-to-a-Sky-expert/ba-p/3711147#M141

Re: NBI FTTP Slow between 8pm and 11pm

jamesn123 — Wed, 02 Sep 2026 10:17:45 GMT

Hi @Tony012334

The only thing I would double check is if there is a device that has some sort of schedule to come on/go off at certain times. This doesnt even need to be an internet connected device, sometimes signals can weirdly interfere. Check heating/hotwater/fridge/freezer/plugs/timers literally anything that could have a similar schedule to the time window you are seeing issues. Also check any device for some sort of scheduled cloud backup/upload/download.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Wed, 02 Sep 2026 18:11:40 GMT

There is nothing of note that I have comming on or off at that time. I can check the logs on my Unifi network and there is no signs of weird activity during the affected timeframe. It does seem to point to upstream congestion as my network latency and speeds are perfect outsifde this window.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Wed, 02 Sep 2026 18:14:23 GMT

My plan tomorrow night is to disconnect my Unifi network from the SKY hub. Leave the Sky hub wifi off and wire my Desktop PC directly to the SKY hub. Then run a ball of speed tests to see what the results will show. Can I ask, what speeds I "SHOULD" be seeing from an NBI/SKY 1gig FTTP connection during peak times? I know there is contention, but what should I expect to see?

Re: NBI FTTP Slow between 8pm and 11pm

Me134 — Thu, 03 Sep 2026 06:53:18 GMT

@Tony012334 wrote:
My plan tomorrow night is to disconnect my Unifi network from the SKY hub. Leave the Sky hub wifi off and wire my Desktop PC directly to the SKY hub. Then run a ball of speed tests to see what the results will show. Can I ask, what speeds I "SHOULD" be seeing from an NBI/SKY 1gig FTTP connection during peak times? I know there is contention, but what should I expect to see?

Every users situation is unique so there's no particular answer to that. What you will have is a minimum 600Mbps(?) on a 900Mbps connection. Your uploads are very consistent which is good, what is it that you're using to measure DL speeds (app and device)? It would help by the way if that table was sorted by date & time to see if there's a pattern there.

I would leave the Sky Hub plugged in for a while as Sky can't help without seeing their hub plugged in.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Thu, 03 Sep 2026 22:15:32 GMT

So today and this evening I disconnected everything from the Sky Hub. The topology is as follows..

The speed test during the day using this configuration were perfect. About 900-950 down and 112 up....consistantly. Then this evening after 8 pm I ran some speed tests and the results were again poor. Some sub 100M sone just about 100M. Please bear in mind I only have one P.C. connected (wired) to the Sky hub during this testing. I also have the Sky hub wireless radios off. See results below..

These are results from earlier in the day with the exact same network topology.

As you can see, very little deviation.

This has to be external network congestion right?

Re: NBI FTTP Slow between 8pm and 11pm

Me134 — Fri, 04 Sep 2026 06:32:04 GMT

@Tony012334 I don't think that's local congestion, it's more likely a bottleneck either where the NBI hand over the stream to Sky, or perhaps at the exchange end where Sky's backhaul capacity at the local exchange before it enters the national data stream.

Perhaps NBI got overly ambitious laying fibre and then dumping too much into the Sky infrastructure all at once?

You need to convince the engineer (and you've got excellent evidence there I think) to log it as an upstream capacity/backhaul fault so it can be escalated to Sky’s network team for further investigation.

BTW, you say you've signed up for 1 year? Do Sky allow that in the RoI or was that a typo?

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Fri, 04 Sep 2026 08:35:13 GMT

Not a typo. I am on a 12 month contract. The Sky engineer is coming Wednesday so I'll show him/her the evidence I have. The engineer is calling between 8 and 5 so is unlikely to see an issue during those hours. As this is a SKY forum is there no SKY employees reading this that can escalate/resolve this as based on my evidence it's likely an backhaul/exchange/congestion issue. Maybe it only effects SKY and maybe if I pointed out my issue to comreg I could switch providers? I do want to give SKY and opertunity to resolve tho.

Re: NBI FTTP Slow between 8pm and 11pm

Me134 — Fri, 04 Sep 2026 08:38:49 GMT

@Tony012334 wrote:
Not a typo. I am on a 12 month contract. The Sky engineer is coming Wednesday so I'll show him/her the evidence I have. The engineer is calling between 8 and 5 so is unlikely to see an issue during those hours. As this is a SKY forum is there no SKY employees reading this that can escalate/resolve this as based on my evidence it's likely an backhaul/exchange/congestion issue. Maybe it only effects SKY and maybe if I pointed out my issue to comreg I could switch providers? I do want to give SKY and opertunity to resolve tho.

You've got an engineer coming out shortly so I doubt comreg would even entertain your communication at the moment (I'm in the UK so no idea of their powers TBH).

Re: NBI FTTP Slow between 8pm and 11pm

TimmyBGood — Fri, 04 Sep 2026 08:57:02 GMT

Minimum contract terms are 12 months in ROI and 24 months in the UK.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Tue, 22 Sep 2026 20:32:53 GMT

So the sky engineer has come out. He was more of a wifi engineer and found no issues. This has been reported back to Sky. I have subsequently been in touch with a customer support agent in Dublin. The have forwarded my complaing to the MBI team. The NBI team have sent a guy out yesterday to check my fiber connection and it all probes out fine. I have explained to all of these people hat the issues in only occuring between the ours of 8-ish to 11-ish pm. SKY have been extremely helpful in this matter but it does appear to me, and eveyone else who has called to check this problem, that is is indeed an ISP related issue. Most likely a bottleneck in the system somewhere. I will post any updates as I am sure Im not alone in this issue. Thanks for the feedback.

Re: NBI FTTP Slow between 8pm and 11pm

Chrisee — Wed, 23 Sep 2026 05:43:58 GMT

@Tony012334 NBI are reported to be using a GPON set up where your connection will be sharing a connection with up to 31 other lines connected to a passive distribution point. While I cannot find any data on the exact setup they use but Openreach in the UK who also use GPON have a shared 2.48Gb/s downstream link. Statistically very few users ever use the bandwidth they buy but we do see reports of 900Mb/s connections going below the 600Mb/s minmum at peak times. Openreach sell connections up to 1.6Gb/s so pretty obviously if you are on a distribution point with a couple of very heavy users there is less bandwidth for the other 30 customers. I would think that more likely than congestion issues in Sky's backhaul.

When talking to an Openreach engineer dealing with an obscure fault on my own FTTP connection he mentioned that there are faults where a rogue ONT can cause issues with other customers on the same passive distribution point. However, as such faults rarely operate to a schedule so that would seem unlikely.

Re: NBI FTTP Slow between 8pm and 11pm

Ronco101 — Mon, 05 Oct 2026 20:36:28 GMT

Hi,

I just wanted to post and say that my experience is identical.

500mb down, 50 up connected, as part of NBI, only 2 weeks ago. Full Ubiquti set up too so I have excellent data and insight into the daily slowdown from 8pm to 11pm. Latency goes from 6ms to 50 ms, download speeds as low as 7mb recorded, in this time window. Uploads speed consistently at 50mb.

We were on starlink and never had any issues. Streaming is a disaster during this time, buffering and streams dropping to very poor quality.

I'm really eager to hear the outcome of your complaint.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Mon, 05 Oct 2026 21:03:17 GMT

So far no improvement. Sky are currently only charging me for 500meg for the remainder of my contract. NBI found no fault and the only logical solution, in my opinion is a bottleneck somewhere down the line. I'm hoping sky's (or whomever the infrastructure belongs to) will catch up to the increase in subscribers. I'm not seeing issues streaming though....just the high latency and speed problems.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Mon, 05 Oct 2026 21:06:38 GMT

The Sky customer support in Dublin have marked my issue as resolved as I have accepted the discounted 1 gig service....for now. I am hoping it improves with time...if not. I shall need to try and alternate supplier.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Tue, 06 Oct 2026 18:13:45 GMT

Have you escalated this to Sky and if so, how did that go? I am in the mid Cork/ Donoughmore area and while I am enjoying a reduced rate for the remainder of my contract, I would still like to see this resolved.

Re: NBI FTTP Slow between 8pm and 11pm

Darragh11 — Wed, 07 Oct 2026 15:08:16 GMT

I’m having a very similar issue on Sky over NBI FTTP.

My connection can be absolutely perfect at times, with around 23–25 ms latency and effectively 0% packet loss, but in the evening it can suddenly become unusable.

I’ve recorded repeated packet loss of around 5–12%, and at worst nearly 20%, along with very high latency and jitter. The problem has also been reproduced over wired Ethernet.

One of the strongest tests I did showed 0% packet loss to the Sky hub locally, but around 11% loss to Cloudflare and 12% loss to Google beyond the router.

Sky sent an engineer out, replaced the Ethernet cable between the NBI ONT and the Sky hub, and escalated the issue to NBI. NBI later came back saying the line was clear, but the problem is still happening.

Sky are currently treating it as a Wi-Fi issue and offering Pods, but that doesn’t explain the wired results.

I’ve now opened a formal complaint with Sky and have also contacted ComReg because the issue has been ongoing for weeks and hasn’t been properly diagnosed.

Your symptoms sound extremely similar to mine, especially the evening slowdown and the fact that NBI report the line as clear. Have you had any further progress or explanation from Sky since your last update?

Re: NBI FTTP Slow between 8pm and 11pm

Ronco101 — Wed, 07 Oct 2026 15:48:59 GMT

Hi Tony, no not yet as I only have the NBI fibre so recently and was doubting if the issue was on my end only to find this forum.

Interestingly I am situated relatively close by, in the Kerry Pike/Clogheen area of Cork.

I will escalate to sky and keep the forum posted of progress.

Re: NBI FTTP Slow between 8pm and 11pm

Tony012334 — Wed, 07 Oct 2026 16:19:32 GMT

Hi Ronco.

Thats why I posted my area on the off-chance we are connected to the same aggregation point/exchange. The NBI chap said I was connected to the exchange in Grenagh, you may be also, and the problem might lie there. Hopefully the issue resolves with time, if not the only option would be to try another ISP in the hopes that their backhaul isn't shared/saturated to the same extent as SKY's. I bet there are numerous more people with the same issue that are not even aware of it. I don't notice the slower speeds or higher latency when I am only streaming Netflix or Amazon. If I was a gamer, or used SKY stream, I reckon the service would be unusable. If I were you, I'd highlight the issue to SKY and you can mention my exact same issue. Good luck.