Concurrent performance of dual FTTP lines

Hi

We have 2 BT fttp broadband lines (carried on the same fibre cable) coming into our business premises. Until recently they were 300/50 lines. Speaking with BT recently, I was offered a new 24 month deal with both lines upgraded to 900/100. The upgrade on both lines has just taken place and testing each line individually shows that they're both delivering the full 900mbps down and 100 up.

I also tested the speed of both lines when performing speed tests on both lines at the same time (to get an idea of the load on our router). What I found was that one line would run at full speed but the other would be much slower. The load on the router cpu never went over 30% and the network switch also showed no issues so I'm sure our network isn't an issue. The PCs doing the speed tests were the same that showed full 900/100 speeds when testing the lines individually so they also weren't a problem.

This isn't a big deal as we don't really need that throughput but, as we now have it, I'd like to know it's working properly. Should this be happening or should we get full speed on both lines at the same time?

Thanks for any light you can shed.

Which ONT do you have? Huawei or Nokia?

To confirm, you're testing this load balancing and not actually testing both lines are you? The first test I would do would be to connect each FTTP line up to a different PC, dial the PPPoE connection, and then kick two speed tests off at the same time. Once you've confirmed that you get the full speeds on both you can look at how your router is doing the load balancing.

As the post above hints at, if you have a 4-port Huawei ONT then it only has a gigabit link internally to the LAN ports so you can't get more than 1Gb of throughput through it.

Edited by jpm (Wed 24-Apr-24 13:27:02)

In reply to a post by XGS_Is_On:

Which ONT do you have? Huawei or Nokia?

According to this page, it's a Huawei 4 port ONT.

That would explain why you can't get full speed on both lines down at the same time.
I take it you get full upload on both?

Thanks
Dan

You need to go back to BT and they need to order a Nokia ONT or another cable out of the CBT.

In reply to a post by danielhyde:

That would explain why you can't get full speed on both lines down at the same time.
I take it you get full upload on both?

Yes, full speed upload on both lines concurrently.

In reply to a post by Josser:

In reply to a post by XGS_Is_On:

Which ONT do you have? Huawei or Nokia?

According to this page, it's a Huawei 4 port ONT.

That'll be it. I was in a similar situation and ended up replacing the Openreach ONT myself with a very slightly different model. Your ONT has only a gigabit connection between the optical and the 4 Ethernet ports so when you're using both that gigabit is shared. Think you've been given a potential solution elsewhere that's a little more 'formal'.

In reply to a post by jpm:

You need to go back to BT and they need to order a Nokia ONT or another cable out of the CBT.

Is that something they will do as a matter of course, as the equipment they installed can't now cope with the service they are now providing? Or will they make a fuss/charge?

David

Edited by Josser (Wed 24-Apr-24 15:00:03)

They won't charge, they might not understand what you are asking for and it might require you to raise it as a complaint though.

The thing to bear in mind is that this isn't a complaint about minimum speed guarantees, this is a complaint that the ONT is physically unable to support the 2x1Gb services that have been provisioned.

It's going to be interesting to hear the result of this. The ONT can support up to 1Gb/s on both lines and speed tests would show that. It can't support 2Gb/s aggregated across the lines. Going to be interesting to see how they respond as it seems the ONT is not suitable to providing 2 services but I have a feeling they are going to argue that both individual lines can perform up to the promised speeds - also, can't remember what the "guaranteed speed" is for 1Gbps but if it is less than 500Mbps then the ONT can deliver it on both lines at once.

I think this should be resolvable if you can get them to give you a new Nokia 4-port ONT. Openreach offer that as a paid-for upgrade; maybe your ISP will either do it for free, or order it and pass on the cost.

Otherwise, I guess you could upgrade one of the lines to a 1.2G or 1.8G service (which not many providers offer yet - EE and ??). That would force them either to upgrade the ONT, or put in a separate 2.5G ONT for that service, and leave the old 4-port for the other one (with a separate cable to the CBT)

Seriously these are the sort of things that make ISPs and Openreach look amateurish, 1.8Gbps of connections going into a 1Gbps backplane. The ISP needs to sort this out with solutions suggested by other contributors.

In reply to a post by ian72:

It's going to be interesting to hear the result of this. The ONT can support up to 1Gb/s on both lines and speed tests would show that. It can't support 2Gb/s aggregated across the lines. Going to be interesting to see how they respond as it seems the ONT is not suitable to providing 2 services but I have a feeling they are going to argue that both individual lines can perform up to the promised speeds - also, can't remember what the "guaranteed speed" is for 1Gbps but if it is less than 500Mbps then the ONT can deliver it on both lines at once.

I have direct contact with the BT lady who placed the order. She was very helpful so I'll raise the issue with her and see what she says.

The order confirmation emails for both lines say "Let us know if your download speed falls below your minimum guaranteed speed (700 Mbps)", so I think there's a valid case that the ONT simply can't provide the minimum guaranteed speed.

I'll report back when I get a response from BT.

David

OK. So far so good.

Just spoke to BT and, apart from being on hold for an eternity, their response was very good. They've agreed to replace/upgrade the ONT (at no charge) and an Openreach engineer is due to be here tomorrow! If all goes to plan then I'll be a happy boy.

I'll let you know how it goes.

David

That all sounds positive, hopefully you get a real Openreach engineer with a Nokia 4-port ONT. Don't sign off on the job being completed if they show up with the same one you have and it doesn't improve anything, push back so they mark the task as not completed and then maybe someone else can have a look.

That is good news and is what would be hoped for, glad they didn't try and justify that both lines were capable of the speeds when used separately.

In reply to a post by jpm:

That all sounds positive, hopefully you get a real Openreach engineer with a Nokia 4-port ONT. Don't sign off on the job being completed if they show up with the same one you have and it doesn't improve anything, push back so they mark the task as not completed and then maybe someone else can have a look.

Is it only the Nokia 4-port that will suffice? Are the Huawei and Nokia the only options they offer or are there others? I will certainly say no to another Huawei (and I was very clear on the phone to BT that an upgrade is needed, not a replacement) but are there other makes/models they might install that will also do the job?

In reply to a post by Josser:

Is it only the Nokia 4-port that will suffice? Are the Huawei and Nokia the only options they offer or are there others? I will certainly say no to another Huawei (and I was very clear on the phone to BT that an upgrade is needed, not a replacement) but are there other makes/models they might install that will also do the job?

AFAIK, the Nokia is the only new 4-port ONT used by Openreach, but if they happen to offer you something else you can quickly Google it.

The other solution would be to give you two standalone 1-port ONTs, of any type - but that would involve pulling another cable back to the CBT.

If this is a residential FTTP product it's probably using GPON which can have contention ratios of up to 1:128 and each port is good for 2.5Gb/s

When testing both lines they may well be contending with each other!

In reply to a post by bsdnazz:

If this is a residential FTTP product it's probably using GPON which can have contention ratios of up to 1:128 and each port is good for 2.5Gb/s

Nope. It's business.

In reply to a post by Josser:

In reply to a post by jpm:

That all sounds positive, hopefully you get a real Openreach engineer with a Nokia 4-port ONT. Don't sign off on the job being completed if they show up with the same one you have and it doesn't improve anything, push back so they mark the task as not completed and then maybe someone else can have a look.

Is it only the Nokia 4-port that will suffice? Are the Huawei and Nokia the only options they offer or are there others? I will certainly say no to another Huawei (and I was very clear on the phone to BT that an upgrade is needed, not a replacement) but are there other makes/models they might install that will also do the job?

Openreach have had 4 vendors for FTTP. They are ECI, Huawei, Nokia and ADTRAN.
They provide the ONT for the home and at the other end of the fibre the OLT in the exchange.

Most vendors want their ONTs to connect to their OLT's and the OLT's are configured as such.

They dropped ECI long ago and haven't installed ECI kit in exchanges for coming on a decade, if not slightly longer.
Did to political pressure they dropped Huawei from new deployments but there remains a very large proportion of Huawei kit in the exchange.

Nokia and Adtran are the 2 current vendors for new deployments.

They install Adtran ONTs for Adtran equipment (OLT's) in the exchange, and Nokia ONT's for Nokia OLT's.

Due to the large amount of Huawei kit already installed in almost every fibre exchange (aka head-end exchange) they cut a deal with Huawei where Huawei would do some kind of licensing allowing Nokia ONT's to be installed in customers homes to connect to Huawei OLT's.
AFAIK no such deal exists with Huawei and Adtran ONT's.

So new FTTP installs will be either...
Nokia ONT on existing Huawei OLT in the exchange
Nokia ONT on Nokia OLT in the exchange
Adtran ONT on Astra OLT in the exchange

If Huawei had remained an active vendor they would/could have delivered Open reach a more capable ONT but as it stands the only 4 port they provided Open reach was picked long before gigabit services were being sold.

So the only option for replacing a Huawei ONT is a Nokia ONT.

In reply to a post by bsdnazz:

If this is a residential FTTP product it's probably using GPON which can have contention ratios of up to 1:128 and each port is good for 2.5Gb/s

When testing both lines they may well be contending with each other!

GPON can have 1:128 splits but Openreach don't use above 1:32, usually deployed with a maximum of 30 lines on the 32 split with 2 kept as spares.

There's no difference in the splits between residential/business on Openreach GEA-FTTP.

Interesting. Presumably it's still a 2.5Gb/s port that up to 30 lines could be connected to. So self contention could still be an issue.

At work we have two 1Gb/s leased lines which are a lot more expensive than FTTP but we do get 1Gb/s on each at the same time as there is no contention on the fibers. It also helps that one fiber is with Openreach and the other with Virgin.

OK. Just when it was going so well...

Openreach engineer turned up but the job he'd been assigned was to fix a fault, not upgrade the ONT. So nothing has changed on the ONT bandwidth front.

Before I go any further, I'm not going to get into any BT or Openreach bashing because I have to say that everyone I've talked to has really tried to help. That's not always been the case with past experience of BT but, this time, I can't fault the attitude of all those involved. Without me asking, the engineer went away to get more information about the issue from his supervisor and other engineers and was then happy to speak to the BT person I had on the phone and enlighten him. The issue seems to be trying to get a slightly non-standard request to be correctly handled by 'the system'. In another life I was a BT employee so I know what sort of monster 'the system' is.

Let me give a bit more detail given to me by the Openreach engineer and BT; it might prove useful to others...

The only option BT seem to have for this issue is to raise a fault even though what is needed is an upgrade to equipment, not the fixing of the fault. As far as OR are concerned, there is no fault so when they turn up there's nothing they can do (unless you're lucky enough to have an engineer who has Nokia ONTs on the van, in which case he might install it simply to clear the job). The OR engineer told me that in my area - the south east - there are only 4 engineers trained to install the Nokia ONTs and they're the only ones with Nokia ONTs on their vans. He also told me that what the engineer needs to see is a B1 ONT MODIFY job (i.e. the provision of an ONT upgrade), not a fault fix. He also said that Openreach aren't making that type of job available to CPs (communications providers) - BT in this case - until mid May. Until that time, the only way you get your ONT upgraded in this situation is to be lucky enough to have an engineer who has Nokia ONTs and is willing to do a favour, or you can raise a complaint which might circumvent the normal process.

After the engineer had left, the BT person almost insisted on raising a complaint to get this fixed. So I'm expecting a call from a complaint handler next week.

So although BT sales might be offering services that 'the system' can't always provide, I'm not unhappy with the situation. I have 2 lines both running at 900Mbps, just not at the same time! That's a fair old jump from the 300Mbps I had a few weeks ago. And BT genuinely seem to be trying to resolve the situation. Once the new job type is made available by Openreach in May, this situation might cease to be a problem.

Anyway, I hope this proves helpful to someone. And I'll post an update when I hear back from BT next week.

David

In reply to a post by Josser:

The OR engineer told me that in my area - the south east - there are only 4 engineers trained to install the Nokia ONTs and they're the only ones with Nokia ONTs on their vans.

Nothing special about installing a Nokia ONT. Can't see why it would require any different training. Connect fibre, scan serial number barcode, register, ONT commissioned.

It's not standard for engineers to have 4 port ONT's in their van but they only install Nokia or Adtran ONT's now.

If only 4 engineers are installing Nokia ONT's what are the rest of them doing?

The ispreview article i saw on this, suggested that there was an upgrade fee to have the four port ont, i would if they do say there will be a fee to push back on it. As your install was a bit of a mess. The fact that the may install time and charge was known for at least three weeks shows lack of understanding from your account manager!

Another update...

BT have raised a complaint which, they say, will allow them to bypass the normal system and get the right job assigned to the right engineer. Appointment booked for 10th May. I'll let you know how it goes.

How easy ( or difficult ) would it be to provide a second fibre from the CBT to the CSP and from the CSP to the ONT location ? if relatively simple they may elect to re provide the second service independently of the existing multi port ONT , on its own single port ONT , maybe not as easy as swapping the existing Huawei ONT for a Nokia one , but may be the solution if trying to procuring a Nokia 4 port ONT proves to be impossible

The issue here seems to be that 'the system' doesn't allow a relatively simple Openreach job to be correctly generated. Swapping a Huawei ONT for a Nokia one seems to be a simple job if it's assigned to an engineer who carries them. BT's only option seems to be to raise a fault. However, that doesn't guarantee that the engineer who turns up will have a Nokia ONT because any engineer should be able to fix my 'fault' regardless of what ONTs they carry.

What the BT complaint guy told me is that the complaint system allows them to bypass the system to some extent. So the plan is to raise a fault and plan the appointment a little way in the future and then, in the time before that appointment, speak directly with Openreach to give them the necessary information to ensure the engineer who turns up knows exactly what the issue is and has the necessary Nokia ONT.

Sounds like a plan, and should be simpler than running more fibre to the premises and installing additional ONTs.

We shall see. The appointment is booked for 10th May. Watch this space!

Hi Josser,

If they still can't sort it let me know. I have a 4 port Huawei here you can use that won't throttle you. I only use one port now so no reason why I can't use my Openreach provided one.

This kit has worked fine for over 3 years. It just needs a minor configuration change and it'll emulate your existing equipment perfectly.

Thanks for the offer - very kind.

Let's see how it goes next Friday. If the right engineer turns up with the right kit there shouldn't be a problem.

Good Luck!

In reply to a post by Josser:

If the right engineer turns up with the right kit there shouldn't be a problem.

Mesdames et messieurs, faites vos jeux!

I'm feeling confident, but not enough to put money on it!

In reply to a post by Josser:

In reply to a post by bsdnazz:

If this is a residential FTTP product it's probably using GPON which can have contention ratios of up to 1:128 and each port is good for 2.5Gb/s

Nope. It's business.

It's still GPON.

Hi,

In reply to a post by therioman:

In reply to a post by Josser:

In reply to a post by bsdnazz:

If this is a residential FTTP product it's probably using GPON which can have contention ratios of up to 1:128 and each port is good for 2.5Gb/s

Nope. It's business.

It's still GPON.

Whilst you are correct, we also know that it is Openreach GPON which won't have a contention ratio above 1:32 and will probably have a contention ratio less than 1:30.

This is of course irrelevant to the OP who wants to be able to achieve a 1974Mbits/sec burst across the two interfaces made available to him (the Openreach product being sold as 900Mbits/sec actually being a 10000Mbits/sec product limited to 987Mbits/sec when presented on a 1Gbits/sec ethernet interface), something quite achievable on a 2.5Gbits/sec GPON network.

In reply to a post by Dassa:

Hi,

In reply to a post by therioman:

In reply to a post by Josser:

... nested quotes trimmed ...

Nope. It's business.

It's still GPON.

Whilst you are correct, we also know that it is Openreach GPON which won't have a contention ratio above 1:32 and will probably have a contention ratio less than 1:30.

Sure, but the point is, 'Business' is not relevant, it's the exact same service and technology at the customer premises level, and I think the point the poster was making was checking it was a GPON service and not something else, which it is of course, but they used the term 'residential' - I think they meant 'regular FTTP' rather than 'are you paying for a business or domestic fttp service'

All sorted!

The Openreach engineer was booked for Friday morning but he turned up today (Thursday) asking if it was a good time to do the job. It was, and he would have come back on Friday if necessary so I'm not complaining. He had been given all the correct details for the job and he had a Nokia 4-port ONT on his van. The swap over was quick and easy which left him a little bewildered when he couldn't get any service on the new ONT. Turns out that the 4 ports run from right to left on the Nokia as opposed to the old Huawei where they ran left to right; hence he had plugged the ethernet cables into ports 3 & 4 rather than 1 & 2. It was his first install of a Nokia 4-port ONT so I'll let him off that one. Once the cables were in the correct ports everything sprang to life.

I now get full 900Mbps concurrently on both lines!
Happy days!

Nice!

I'm glad it was sorted for you in the nicest physical way possible! 😁

In reply to a post by Josser:

The swap over was quick and easy which left him a little bewildered when he couldn't get any service on the new ONT. Turns out that the 4 ports run from right to left on the Nokia as opposed to the old Huawei where they ran left to right; hence he had plugged the ethernet cables into ports 3 & 4 rather than 1 & 2.

A useful snippet for others who run into this problem with unexpected ethernet port numbering on ONTs

Brilliant, well done for sticking at it and listening to all the advice and getting it sorted.