Openreach deadlocked FTTP fault, Zen refusing to do anything

Since the start of our contract with Zen in August 2023, our FTTP 300 service has been not performing as expected, with upload speeds as low as 8Mbit over Ethernet with no other network traffic, and continuous packet loss.

Between October 2023 and May 2024, we’ve had 7 Openreach engineers, a new Nokia ONT with 2.5G port (replacing the original 1G port version) and a new Fritz!Box 7530 AX from Zen (to replace the original Fritz!Box 7530 version).

Most of the Openreach engineers found faults, such as the cable between the CBT (in the manhole) and the CSP being very tight, no slack and a curvature greater then 90 degrees. Zen also confirmed the following (copied exactly from an email they sent me):

“Openreach are not prepared to take any further action, they have also advised that the issue covers only a small area and a minimal number of properties”

When I clarified this statement with Zen over the phone, I was told “approximately 7 properties” in the local area were experiencing the exact same issue, including packet loss. Zen has also previously said another customer on a neighbouring road (they told me which road) was also experiencing the same issues and packet loss, and although they’re on a different CBT, they’re connected to the same splitter as us, which as far as I am aware has never been investigated by Openreach.

Zen has offered to reduce the bill by only £4/month until the end of the contract or end the contract altogether so we can go elsewhere. However, our Zen faults manager has already said switching ISP will not resolve this issue as Zen has proven the issue to be on the Openreach network between our property/splitter and the headend. They also said between the splitter and the headend there is no other splitter/node, it’s a straight cable to the exchange.

To prove Zen’s network is not the issue, Zen requested a migration in the exchange from their equipment to BT Wholesale, which Openreach actioned a few days later so it no longer says our PoP is BNG or xxx-LON in the Fritz logs.

We’ve had over 7 Openreach engineers sent out between October 2023 and May 2024, because Zen kept finding faults that Openreach claimed did not exist until Openreach finally decided to deadlock the fault with Zen in May 2024 after which Zen said there was nothing more they could do but suggest I complaint to CISAS. OfCom said Zen should raise an Industrial Level Complaint as Openreach has deadlocked the fault, not Zen, but Zen has refused to do this leaving me now with no choice but to make a complaint through CISAS.

Has anyone else experienced this issue before with an ISP? Other than complain to CISAS, I don’t know what else I can do.

One thing you could try is terminate the contract with Zen and migrate to A&A who say, on their "We'll fix your line" page that:

"Give us a month and we'll sort your problem broadband line or your money back. If you are migrating your service to us, even though you know you have a problem with your broadband line, we'll take on the fault. We'll tackle the problem and get it fixed within one month. If we don't, then you can migrate away, and owe us nothing for your migration to us and your service charges for that month."

They claim that they've failed to get a fault fixed only once in ten years.

The disadvantage is that if they succeed in fixing it, you'll be contracted with them for a year and their price is a little higher than Zen's.

Sounds a good option

In reply to a post by ashdown:

One thing you could try is terminate the contract with Zen and migrate to A&A who say, on their "We'll fix your line" page that:

They don't do it for FTTP. (That's for FTTC or SoGEA only)

Thanks - I wasn't aware of that. May still be worth having a word - they do seem to be more assertive than most when dealing with Openreach.

I'm not convinced they'd take on "there's a known fault in the network, Openreach have found it but are refusing to fix it" anyway.

If Zen cannot be bothered to push this any further then it might be time for the complaint to go into the Clive Selley mailbox. I'd also argue that since the service has a known fault on that it is not fit for purpose and Zen owe you a refund on your subscription charges. You have rights as a consumer that aren't just whatever ISPs agree to with Ofcom - admission of a fault makes the service not fit for purpose.

I wonder what skill level the Openreach engineers were that come out to look at this issue (there are some amazingly skilled engineers who could investigate this but may not have been involved), there are only so many possible issues with your service (and the others having the same issue on your PON). Openreach can't be allowed to abandon these sort of issues.

I'd also suggest that you speak to AAISP - they have a very good working relationship with Openreach and can pull the right strings to resolve issue.

Do keep us updated!

Thanks for your replies.

I have been running a BQM lately and it shows the packet loss:

My Broadband Ping

The service is definitely not fit for purpose. MJ Quinn did the initial install and messed that up according to the first engineer we had. In the early days, Openreach were instructed to send an N23 engineer but instead sent an N11 engineer. On a few occasions, they sent an engineer who hadn’t completed his training, apparently because of financial reasons (according to his manager). Really nice lad, but very limited to what he could do.

Openreach had apparently investigated the exchange at the start but Zen had no record of any attendance. Then many months later they started working at the exchange, cleaning the fibre connections, changing us to a different Layer 2 switch, and so on. But at no point have they checked the splitter which Zen believe to be the root cause of the issue.

I’m guessing CISAS will look at this from all angles, including the few occasions we had Openreach claim an engineer visited but no one was there, which generated a charge, which was then refunded by Zen. Openreach has been very sneaky with this issue, and now it’s deadlocked which leaves me thinking they know what the problem is, but either the cost to fix is too great or it’ll take too long to fix resulting in extended periods of downtime for everyone on that splitter. That’s just my opinion.

If Openreach threw the kitchen sink at it they COULD find this issue, its possible its the splitter but thats just a set of mirrors but wouldn't be too hard to replace, one spliced fibre in and upto 30 (some will say 32) spliced fibres out and a bit of labour by someone. The fact that its not just you having the issue says a lot especially if the affected properties on your PON are across multi ISPs. There is not much that can go wrong on FTTP really, has any of the engineers told you what your light level is?

Yes, I’m sure it was around 15, but I bought a cheap light monitor from Amazon recently to check the light level myself and it was 15.98, but if you want I can check again and let you know.

In reply to a post by adhdave:

Yes, I’m sure it was around 15, but I bought a cheap light monitor from Amazon recently to check the light level myself and it was 15.98, but if you want I can check again and let you know.

-15db is fine and within the tolerance of -10 to -25db.

The Zen refusing to do what Ofcom suggested is what annoys me with this wholesaler system.

I would give AAISP a shot, if they not prepared to take it on, I assume they would tell you before the order went through so you wouldnt be wasting your time, tell them up front the service has an outstanding fault.

I expect the reason Ofcom told you to get Zen to do the complaint is that you have no contract with Openreach. If you havent done so already I would inform them Zen refused to do it.

Emailing the Openreach CEO is also a solid option, I think you would be fair in that its a last resort sort of thing given OR have deadlocked it.

Edited by Chrysalis (Wed 17-Jul-24 21:07:02)

Hi, since having full fibre installed 3 weeks ago.. it’s been such a headache. And I’ve been having this exact same issue!

Up to 500 down often, great latency, great stability, no packet loss etc but horrendous upload speed.

Have spent probably 8 hours collectively on the phone. For the first week my equipment etc kept getting blamed, until I finally plugged in Ethernet to the ONT on laptop and replicated the results time and time again.

I even switched ISP (PlusNet to EE), exact same issue. PlusNet already sent me a new hub, it’s clearly not that.

Since had both a Qube and Openreach engineer sent, who proceeded to blame each other. They are so baffled/confused.


Glad I’m not the only one having this extremely rare issue.. because nobody would believe me until both sets of engineers struggled to. No advisors, engineers had never seen anything like it before. Hoping more people with this speak out, were made to feel like the only ones but certainly aren’t. The OR

OR engineer was getting quite frustrated with the results, said it’s ridiculous. He also the other day upgraded my ONT from 1 gig to 2.5 gig, as apparently lots of issues on 1 gig. Changed.. absolutely nothing.

No it’s not the Ethernet cables, nor my equipment or devices It has been such a nightmare. Only difference with mine is there is no known faults.. apparently everything’s perfect.

For anyone interested the r/Openreach subreddit, I posted thorough details and updates, my post will be easy to find.. lots of good advice by fellow sub members who know what they’re doing. Somebody linked this post.
Hours of resetting, rebooting (rebuilding). To no prevail.

I do wonder if it is an area fault where I am, and nobody else (an area with mostly retired folks) has noticed.

Given it all way too much time and energy. But Openreach engineer sent over again Friday 🤣 and the cycle continues.

Maybe would be worth the reduced bill.. but personally would rather it fixed.



EE customer support, I’d been so very nice and patient. Was only today when I told them I’ll be boycotting my next bill, and if pursued for it then I’ll escalate it to CISSA until this is fixed, as I’m promised ‘75 avg’ upload as per contract, that I was actually taken seriously.


Last thing also, my hub for EE wasn’t allowing any advisors to test, the one yesterday said that could be linked. That’s fixed itself today. Glad they can finally see it for themselves.

AA are so much more expensive than Zen. We’re paying £40 for 300/50 and a 300Mbit service from AA is £55/month. I could always ask their sales team first and see what they say but I’m also conscious that if we leave Zen before CISAS has responded, they’re unlikely to do anything. I do have the Zen CEOs email address, and I was going to email him as his company mission in his blog has always been “people should come first”, but this doesn’t seem to be the case for me.

Link

Well exhaust your options first with Zen, and perhaps try OR CEO after that, but AAISP could be a fall back option if none of those get anywhere.

Awesome, I’ll certainly consider that, thanks.

I just noticed this post has been referenced on Reddit, as per the last user, and I also did things like bypass the router and connect my laptop into the ONT and establish a PPPoE connection, but got the same issue.

Using my laptop connected to the router via Ethernet…

When I do a speed test using ThinkBroadband, I get 300 down but only manage between 20 and 27Mbit up.

With CloudFlare’s speed test, I also get 300Mbit down but between 15 and 25Mbit up. It says my location is Ipswich (it’s actually Ellesmere Port) and the server is Manchester, but hey. CF always says there’s packet loss too.

With SpeedTest.net, doing a speed test to Zen’s server shows the full download and upload speed, but with packet loss. On some occasions, the download shoot’s up to 300, pauses, then suddenly drops to 250 and continues to fall. Zen told me that’s a clear indication of packet loss.

However, doing a speed test to another server produces worse results, even if the server is located in the same location, such as Hyperoptic.

Our Apple TV also keeps telling me a lot of videos are being buffered, and to check the internet connection.

The Xbox speed test always shows 300 down and between 6 and 12 up, with a ping of ~18ms and 1% packet loss. Online gaming is often very choppy too. But if I play the same games over my Three 4G connection with only 2 out of 4 bars of signal, it’s more reliable than the FTTP!

Your issue doesn't sound the same as what the OP has. Sounds more like a backhaul issue to be honest.

Also should have said switching between ISPs who use BT Wholesale proves nothing as they both use the same cable links from the OLT, Would have been better switching to a ISP who doesn't use BT Wholesale.

Edited by PCJM40 (Wed 17-Jul-24 22:38:00)

I wouldn't get too hung up on the packet loss on the BQM.

A small amount of packet loss on the BQM is normal.wirh a Fritzbox. They are known for not responding to ping packets in a timely fashion. It's been covered on this forum before in previous threads.

The upload speed fault is the one you need to pursue with Zen.

Well, the OR engineer who came on behalf of PlusNet was convinced it was a PlusNet thing and that all will be fixed when I switch to EE 🤷. Perhaps your words would’ve helped him out.

Ironically was the same engineer who then came on behalf of EE, and said the line’s fine.. he’s advised to close the case and BT will have to look at it

In reply to a post by mikel543:

A small amount of packet loss on the BQM is normal with a Fritzbox. They are known for not responding to ping packets in a timely fashion.

Good point, I had forgotten about the known issue of the Fritzbox dropping pings which shows up as packet loss on a BQM.

Have you tried https://packetlosstest.com/ to see if you are actually losing packets? Make sure you select UK for the target server at the bottom of page.

Edited by PCJM40 (Thu 18-Jul-24 13:33:51)

I had exact same issues as you but for Downloads. on a 500mbps and test file from TBB was showing 40 minutes.

Someone suggested enabling mult threading on the browser, that helped to bring it down to 8 to 10 minutes.

Long story short, changed providers and still same issue OR found no fault, this was going on for few months,

Touch wood tested today and for the first time ever TBB speed tests showed over 450 and normally was around 70, file downoad was 20 secondish, nothing changed for me as I had given up on the issue as never any fault. T

he only thing I can think of, is city fibre were connecting their fibre to the pull outside my house but they didnt use ducts as connected from a pole further up the road, perhaps they jiggled somehting

In reply to a post by PCJM40:

In reply to a post by mikel543:

A small amount of packet loss on the BQM is normal with a Fritzbox. They are known for not responding to ping packets in a timely fashion.

Good point, I had forgotten about the known issue of the Fritzbox dropping pings which shows up as packet loss on a BQM.

Have you tried https://packetlosstest.com/ to see if you are actually losing packets? Make sure you select UK for the target server at the bottom of page.

I’m still experiencing packet loss and I can see it occurring via packetlosstest.com, and also our neighbour is with EE via Openreach and experiencing the same issues as us.

Zen has been in touch and asked if we’d like to upgrade because the contract is up next month. I’m tempted to upgrade to the next package up, which is 500/70.

But by doing so, is that likely to result in more packet loss because the connection is faster? Or could it go the other way and result in more speed but less packet loss, or possibly even no packet loss altogether?

In reply to a post by adhdave:

I’m still experiencing packet loss and I can see it occurring via packetlosstest.com, and also our neighbour is with EE via Openreach and experiencing the same issues as us.

How much is a "small amount"?

Packet loss of even 0.1% *can* badly affect TCP performance, when talking to a distant server. The maximum speed you can get from a TCP session is a function of the packet loss and round-trip time:
https://en.wikipedia.org/wiki/TCP_tuning#Packet_loss

e.g. for a connection with 0.1% packet loss and 70ms RTT (East coast USA):

1460 / 0.07 / sqrt(0.001) = 659560 bytes/sec

Multiply by 8 for bits per second and you get ~5.2 Mbps

In reply to a post by adhdave:

Zen has been in touch and asked if we’d like to upgrade because the contract is up next month. I’m tempted to upgrade to the next package up, which is 500/70.

But by doing so, is that likely to result in more packet loss because the connection is faster? Or could it go the other way and result in more speed but less packet loss, or possibly even no packet loss altogether?

It will almost certainly make no difference to packet loss. It's just a change in profile on the OLT.

Low levels of packet loss are hard to measure directly, and you can get false readings due to (for example) the router itself dropping pings addressed to itself when it's busy.

IMO, the best approach is to do a single-threaded speed test, to several servers some distance away (e.g. Europe or USA). If you find you get lower speeds to servers with a larger round-trip time, then this is evidence of low-level packet loss and you can use the formula above to work backwards to estimate the amount.

If you are getting good speedtest performance to all these sites, or the pattern is inconsistent, then likely packet loss is just a red herring.

What actions did you take after posting in here ~7 months ago and being given advice?