Broadband Users on CityFibre’s UK Network Suffer Nokia ONT Problems UPDATE2
Some broadband ISP customers on Cityfibre’s national Fibre-to-the-Premises (FTTP) network, which covers 4 million UK premises, are currently experiencing ongoing connectivity problems due to an unspecified issue that seems to only be affecting those that have one of Nokia’s Optical Network Terminals (ONT) installed inside their building.
Just for context. The ONT / ONU or optical modem device is usually installed inside your home or office (wall hung), near to where the fibre optic cable physically enters your property, and its primary job is simply to take the optical signal and convert it into an electrical one that can be connected to your broadband router via a Local Area Network (Ethernet) port. The standard ONT is usually a very small single port device.
Most of the residential customers on CityFibre’s network are probably connected using the ONT supplied by Calix, which tend to be coloured black (there are several models in circulation, but they’re usually the same colour). By comparison, Nokia‘s ONT is more of a cream white colour and has rounded edges. This is most commonly found in CityFibre’s newer XGS-PON (10Gbps) areas (roll-out update), although Calix also do some of the XGS-PON kit.
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However, several of ISPreview’s readers from different parts of the UK have been reporting problems with Nokia’s ONT units since just after 8pm last night, which has also generated a related post on Reddit. As one of our readers (Jonny) said this morning: “My connection went down at 20:30 last night and [my ISP] have confirmed a wider network issue to me in a support ticket. Symptoms are a steady flashing PON light, which is supposedly indicative of a firmware update. Outage has so far been 15 hours.”
The fault is not believed to be impacting too many of CityFibre’s connections and as a result we haven’t seen many of their ISPs putting out a notice about it yet, although we did get this from No One Internet (Leetline).
Jan 09, 10:09 AM
CityFibre is aware of an issue impacting a small number of FTTH and business FTTP customers. We have engaged with our technical teams who are currently investigating to resolve the underlying issue as quickly as possible, and we are also working to minimise impact to those customers who are affected. We apologise for any inconvenience this is causing.
We have asked for a comment from CityFibre too and will report back when one arrives. The hope is that this fault can be rectified remotely, but if it is a problem with a borked firmware update, then those can sometimes only be rectified by a device replacement. But at this time, the specifics are not clear on what has actually gone wrong.
UPDATE 4:29pm
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A spokesperson for CityFibre told ISPreview: “A small number of residential premises on our network have been affected by a configuration issue, which our team is working to resolve as quickly as possible. We sincerely apologise for any inconvenience caused.”
UPDATE 10th Jan 2025 @ 7:07am
The last update posted just after 9pm last night reported that CityFibre’s Major Incident Management team had confirmed how “all affected services have been restored through the troubleshooting efforts on the live investigation bridge.” But due to the nature of the issue, the incident will remain open for 24 hours to monitor and address any potential issues that may arise.
Mark is a professional technology writer, IT consultant and computer engineer from Dorset (England), he also founded ISPreview in 1999 and enjoys analysing the latest telecoms and broadband developments. Find me on X (Twitter), Mastodon, Facebook, BlueSky, Threads.net and Linkedin.
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Our Nokia ONT is fine so far – thank goodness. Might be worth trying the factory reset button for anyone affected. You’d think that would restore the last known good firmware.
It might not. Unless you know exactly what a factory reset does to the device, you may want to refrain from bricking your ONT.
If you’re impacted, just let your ISP know and wait for instructions. Clearly, here, we’re dealing with a remote update that did not go as planned. They’ll most likely roll it back.
Perhaps but it is part of the self-help guide for solving ONT issues issued by my ISP so I doubt it will brick it.
https://www.zen.co.uk/help-support/cityfibre-ont-diagnostics/
Arthur & John,
It always reminds me when someones telephone/computer stopped working that some advise them to call/email for help – unless the help is in earshot, you dont get much.
So back to a (national) resillient infrastructure (inc voip..)and of course particulalry ICE…
grate britian
And the story here is??? Next we’ll be hearing that one engineer arrived for an appointment 5 minutes late
Did you read the article? Several thousand customers across the UK are probably offline because of an ONT fault. That’s an unusual problem and can be difficult to fix. I’m one of them.
Lister I did read it – it says “the fault is not believed to be impacting too many of CityFibre’s connections”…. No reference to “several thousand” – did you make that up?
@Lister. Scale is not currently known with any confidence, from what I can see. No One Internet calls it a “Minor Incident” and other ISPs, like Yayzi, call it a “Major Incident”. But this will vary from ISP to ISP, as some are more focused on certain locations.
However, CityFibre do have something like c.450,000 connections on their network of 4 million premises, so it’s probably not unreasonable for the figure to be in the low thousands.
Big providers often use the word “small”, but you always have to take that in proportion to the scale of their network (i.e. small can still mean a lot of affected customers). This particular outage is unique enough to be worthy of a mention.
Any update on when cityfibre will go live with more houses in the medway area they were building 2 years ago then nothing.
Possibly never. CityFibre now only appear to be interested in Project Gigabit subsidised builds. Their strategy for significant enalargement seems to be waiting for other altnets to go bust.
ours went down last night at the same time, been told by Zen its a UK Wide issue with Nokia ONT’s
Major Incident Update
Latest Update:
(09/01/2025 14:33) CityFibre’s technical teams are working closely with our vendor to troubleshoot and resolve the issue impacting a small number of residential premises. We are making every effort to address this issue as quickly as possible while minimising the inconvenience to the affected customers. We sincerely apologise for any disruption this may have caused and appreciate your patience as we work toward a resolution.
Next update at: 16:00 09/01/2025
All Updates:
(09/01/2025 14:33) CityFibre’s technical teams are working closely with our vendor to troubleshoot and resolve the issue impacting a small number of residential premises. We are making every effort to address this issue as quickly as possible while minimising the inconvenience to the affected customers. We sincerely apologise for any disruption this may have caused and appreciate your patience as we work toward a resolution.
Next update at: 16:00 09/01/2025
(09/01/2025 12:50) CityFibre’s technical teams are actively collaborating with our vendor to troubleshoot and resolve the issue as quickly as possible. We are committed to minimising the impact to the small number of affected customers and sincerely apologise for any inconvenience caused.
Next update at: 14:30 09/01/2025
(09/01/2025 11:34) CityFibre is aware of an issue impacting a small number of FTTH and business FTTP customers. We have engaged with our technical teams who are currently investigating to resolve the underlying issue as quickly as possible, and we are also working to minimise impact to those customers who are affected. We apologise for any inconvenience this is causing.
Next update at: 13:00 09/01/2025
Been there. “Incident managers” demanding attendance at an “incident meeting” on the hour every hour. You finally get everyone dialled in by ten past then the ones who like the sound of their own voice blather on and you might get out by half past with an admonishment to be back for the next meeting on the hour. Eventually I point out that I can attend the meeting or work on the problem; choose.
Billy,
Take it you’ve worked for VM in the past?
@Lee. No. My closest contact was providing services to Virgin Mobile in Trowbridge about a thousand years ago. They were a good bunch and the coffee was good. Bureaucracy is endemic 🙂
I did a small amount of work in the Virgin Mobile office before it closed down, they moved a small amount of staff to the VM hub site in Trowbridge after. Now Virgin Mobile doesn’t exist I assume they’re all gone now.
@Billy Shears
I too recall ‘senior’ management interest often appearing out of the woodwork, and using the same:
Do you want me to spend time updating you and.. and, or would you rather we got on with fixing the problem?
May I suggest you all get together and help; nominate 1 person to shadow us and then they can then update you, therefore not actually interferring with fix work progression.
Help or hinder I’ll leave to your collective discretions.
Oh in case you’ve forgotten the SLA on this has a penalty of 150K an hour, so this call conversation has cost us £££££?
And by the way I’m already liaising with x, the client’s senior service management contact, keeping them on-side…
Respect can be hard to establish ;-} ‘common sense’ seems to anything but common, about as common as hens teeth still?
Nice to know (not) managemewnt ‘elightenment’ is still stuck with dumbness 30 years on !:-o
Yayzi are calling it “ONT sessions unlinking” which doesn’t sound good. We had CityFibre here by about noon (IDNet service with critical care level) and they did something and it started working. It doesn’t look like the ONT was replaced so presumably they provisioned it again.
This is not acceptable.
Very soon home broadband connections will become critical pieces of infrastructure when people rely on them for VoIP telephone calls, calls to emergency services, etc.
The cracks in Cityfibre’s network are already becoming apparent, a network supposedly using cutting edge technology.
Of course problems occur but you’d expect them to resolved in a timely manner. You have to question if these delays in resolving problems is down to Cityfibre cutting costs by making staff redundant?
Considering you used to work there, before being fired, you should know that it’s a non resilient service.
It’s performing as expected to the designed SLA.
And they are using the latest Nokia technology. The same as others including Openreach.
CF assurance is gold standard, any description otherwise is madness.
Ha , Gold obviously isn’t worth what is once was, no doubt ~4000 might have a different view of ‘gold standard’. FAncy building anything that may be required to provide emergency contact with single points of infrastructure failure post 2000.
Perhaps the modern perception of gold is more like brass (although that has value and real quality use), so perhaps just gilt/spin/’marketing’/’regulation’ plating these days.