This topic

Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 14:22:43 GMT

hi all

In December my very elderly parents were told copper was ending and had to go full fibre

They are very, very dependent on the home phone

Engineers came from openreach and installed all the kit and is all physically working, transition was meant be seamless but have now been without their phone line for a month.

Have been present when all calls made and order was auto cancelled, re-ordeed then auto cancelled again, sales rep opening a new account will solve it 100% as system was playing up, date passed and they called stating having difficulty migrating number and more delays.

Been heavily researching comparable issues on line and one that comes up fairly regularly is incorrect serial number from ont box

I checked with the help team and they have the GPON number registered as the serial number as opposed to the unique ont serial number

Our ont has a gpon, serial and mac number

My uneducated understanding is Global Passive Optical Network number is not unique is for a service cluster but the actual Serial number on ont is unique and will supply the isp specific service

Anyone with a better understanding than myself could the Engineer registering the gpon over the unique serial number be the cause of everything?

The fttp team seemed confident this could be the cause

Running out of ideas now and it is having a massive negative health impact on my father.

Currently in the middle of trying to resolve and will be getting a call next week

When it all gets sorted I'll write a timeline so it can help others

All feedback welcome

Thank you

Re: Fttp from copper problems since December

WSH — Fri, 23 Jan 2026 14:32:54 GMT

Does the broadband work, (and the problem is just the phone)? If so, the serial number will be correct.

Re: Fttp from copper problems since December

WSH — Fri, 23 Jan 2026 14:34:56 GMT

If it is just the phone and the broadband works, have they moved the phone plug from the socket on the wall to the green socket on the back of the Smart Hub 2?

Re: Fttp from copper problems since December

licquorice — Fri, 23 Jan 2026 14:47:33 GMT

Does the hub manager show a phone number or 'not configured' ?

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 14:58:32 GMT

Phone shows not configured

Re: Fttp from copper problems since December

licquorice — Fri, 23 Jan 2026 15:04:05 GMT

Then only BT customer services can resolve it.

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 15:05:45 GMT

The broadband works but technically we don't have an active package, old one was cancelled when account closed and every order since on old account auto closed

New order on new account open but cannot complete at the moment we should be on ff300 with digital voice

we are just getting a random 5mbs

Openreach seem to not be able to port number over and bt cannot start new package

I asked adviser what ont number they should have registered and ran through gpon number serial number and mac

They had gpon number as serial number but it needs to be the number beginning S/N which is different from the gpon

Tried absolutely everything either the hub etc, done everything locally hardware side

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 15:06:54 GMT

Yep all this is done

Re: Fttp from copper problems since December

WSH — Fri, 23 Jan 2026 15:16:52 GMT

I think there might be confusion with the serial number business.

I might be wrong here, as it's not my field, but I suspect it is Openreach that need the serial number to enter into the OLT at the Fibre Handover. BT would not need that number and so would not have it. All they would have is a reference number.

Re: Fttp from copper problems since December

iniltous — Fri, 23 Jan 2026 15:26:44 GMT

You have a few misconceptions, the ONT serial number is used to authenticate the ONT onto the OLT ( the headend equipment) this is Openreach equipment and although the ISP can ‘see’ this , it’s not their concern unless the customer reads out a serial number that doesn’t match , thus really coukd only be an issue if the customer got a OBT from Ebay for example and connected it themselves…Openreach use an application on their works device that scans the bar code and sends the information to OR , its not anything to do with an individual ISP , and if it were unsuccessful the PON light on the ONT would flash , if it’s steady green then the authentication is done and successful (with the correct ONT serial number ) , so any concern regarding numbers on the ONT is misplaced .

GPON is just Gigabit Passive Optical Network and simply describes the transmission standard any GPON number on the ONT is irrelevant.

Were your parents already broadband customers or was broadband being provided ‘for free’ just to maintain a phone service , so in effect they are still phone only customers, they just happen to have a broadband router that is of no use apart from it provides a place to connect the landline phone instrument ?

In this case it’s the status of the router that’s probably most important , if the light on the router shows connected to the internet but there is no telephone service (and you have apparently checked the router stats to see if the phone shows as configured or not ) , then it’s an account issue …and possibly if broadband was provided for free , that may be the issue as other systems may fail if there is no one paying for broadband.

FWIW , it’s not possible to enter the wrong number from the ONT into the headend , the format and header on the serial number are necessary, and if it were possible to scan the wrong information, then the authentication could never take place , so if that’s your concern, check the PON light , if it’s steady green then it’s fine .

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 15:20:02 GMT

Hi, yes bt have submitted a request to openreach

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 15:25:30 GMT

They were broadband and copper customers, otn is working fine and all lights are on, as mentioned they have been receiving a nominal broadband speed.

Hub manager has stated not configured since the day they started up the full fibre, activation day came and went and all the issues outlined in first post in-between.

Bear with me on this but

So if bt only have the GPON registered their side as the serial number then that would not impact the order or service?

The actual Serial number on the ont is irrelevant?

Re: Fttp from copper problems since December

licquorice — Fri, 23 Jan 2026 15:34:01 GMT

Don't try to second guess what BT do or do not require. All that BT need to know is your Digital Voice is not configured correctly and they need to resolve it. All the talk of serial numbers is just a red herring if your broadband is working correctly.

I have moved your post to a more appropriate board as it is a DV problem rather than broadband.

Re: Fttp from copper problems since December

iniltous — Fri, 23 Jan 2026 15:53:06 GMT

No , that’s the opposite of what’s the case , only the serial number is needed for the headend to ‘talk’ to the ONT , the other numbers are manufacturing numbers or whatever and serve no purpose regarding authentication….in your case the serial number must be recorded correctly otherwise the PON light would flash indicating no authentication .

The ISP can ‘see’ the serial number that Openreach have recorded , although it’s not really for their use …but it’s a simple check , if for example someone ordered service for an address that had FTTP installed before they moved in , but it didn’t work on the day they arranged , the ISP may say , can you read out the serial number on the ONT to make sure Openreach records and the physical ONT match up,

say as an (unlikely) example, a house having two flats , both have ONTs but somehow they were swapped around , flat 1 having flat 2’s ONT serial number recorded and vice versa, this would be a simple check , but that’s all it is , the ISP not responsible for that , Openreach is .

Once the serial number is authenticated, the headend knows that a particular ONT serial number is associated with a particular ISP network, so sends the data to and from the correct ISP network via the ISP interconnections , if there were any concerns with the ONT it’s a simple job to swap it with a new one ….it was quite common for people moving into addresses with FTTP already fitted to not have an ONT because the previous occupant took it with them (in fact Openreach now put a sticker on the ONT saying , ‘moving house ?, please leave me here ‘ but it’s simple in thise cases to put a new ONT in place and update the OLT with the new ONT serial number …if it’s a concern ask for the ONT to be replaced by Openreach

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 15:42:32 GMT

Thank you, problem is been at this for a month and since they installed full fibre, they have not been able to action sny new contract, activate digital voice or provide contract broadband.

Probably spent close to 16 hours on the phone, ghosted by 2 x technical support who would call back on given days and parents were just pushed to sales team.

Each time they stated it would be up by x date, I don't know what they can do to fix it, seem very reluctant to send an engineer and want to resolve over phone but give no identification of problem and how it will be resolved

Re: Fttp from copper problems since December

WSH — Fri, 23 Jan 2026 15:45:30 GMT

As Licquorice says, talk of the serial number is irrelevant. If the ONT lights are green then it is connected, so the serial number must be correct.

I think what is confusing you is the Openreach/BT confusion that people still have today. They have been separate companies for many years now, (at OFCOM’s insistence).

Openreach will have the serial number as the physical connection is their business and they need it for the OLT at the fibre exchange.

BT provide your service and probably don’t have that number as they don’t need it.

It sounds as though the service is at fault, not the physical connection and so the serial number is not relevant. If so, it is a software problem and so they won't send an engineer to the premises, as that would not be needed.

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 15:53:04 GMT

Thank you, this makes some sense, it's just very very confusing for me especially as I'm trying to sort out a problem from distance

In very lay terms this is the ont what is the reference number bt would need to provide a unique customer package which are generic

Re: Fttp from copper problems since December

Minionbanana — Fri, 23 Jan 2026 15:55:33 GMT

Thank you makes sense

Re: Fttp from copper problems since December

licquorice — Fri, 23 Jan 2026 15:58:38 GMT

Forget all about the ONT, the problem is not a physical one, DV has not been configured by BT.

I will flag your problem to the mods although they don't have account access they may be able to expedite matters.

Re: Fttp from copper problems since December

Christopher_G — Fri, 23 Jan 2026 16:01:07 GMT

Hi @Minionbanana

Welcome to the community.

I know you're getting some really helpful support here from @licquorice, @iniltous and @WSH. I'm just concerned by the length of time your parents have been having this problem for, and that you feel you're not getting the support you need from us.

I've sent you a private message, just to try and get you some help.

Chris