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Message 1 of 6

BT fiber 900 - Poor upload speeds (50mb/s~) - Possibly capped?

Good evening all,

I seem to be having my BT fiber 900 upload speeds capped at 50mb/s, with a 45mb/s~ average. Download speeds are perfect. 

I see a few posts on the forums where other members have experienced issues with their BT fiber 900 package where the upload speeds never raised beyond 50 and it did turn out to be a cap which was quickly lifted.

See the speed-test results below from



Additional notes and diagnostics taken:

  • I use a 3rd party router. However, I've swapped back to the BT SH2 while testing and experienced the same speeds, about 1000,45.
  • I've also connected directly to the ONT and setup PPPoE connection on my laptop, getting around 1000/50.
  • 3 speed tests taken on 990/40, 1000/46, 990/47


So it seems the issue is external to my network. Hence why I suggest a possible speed cap, which appears to have been the case on a number of other members posts. Hopefully this can be a similarly quick and easy fix?

Thanks in advance.


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Message 2 of 6

Re: BT fiber 900 - Poor upload speeds (50mb/s~) - Possibly capped?

The 50Mb ‘limit’ thats often posted about , is the way some SH2’s are configured then  dispatched, leaving them connected for a while , gives chance for the router firmware to be automatically updated and the 50Mb limit removed, if it doesn’t happen automatically, then a targeted upload of new firmware may be necessary,

This cannot be your issue as you say you are using a third party router , that obviously cannot have the same ‘problem’ as the BT Hub , plus you have observed the same issue when removing the router entirely and connecting directly to the ONT.

Its possible your speed profile is incorrect configured, but the only speed profile that has 110Mb  upload, is with the 900Mb download, and you are getting that download speed , for your profile to be configured incorrectly, would mean that the ISP when  setting your 900/110 profile , rather than it being a one step selection , setting both from a set menu of profile speeds , would have to done in two steps , setting the download correctly , but whoever or whatever selected the upload speed , incorrectly assigned 50Mb instead of 110, having said that ,  you do seem to have ‘proved’ the issue as far as you reasonably could , with the exception of trying a different wired device capable of using the speeds available.

You  should contact FTTP customer service reps  , the number can be found by searching this forum , hopefully they will check and possibly reset your profile ( if it’s necessary)  , in the meantime, to conclusively prove its not your kit ( and it could be ) , do you have another device to try , or can try your device on some other network that delivers greater than 50Mb upload, as it’s possible you may be advised that the profile is set correctly, or that they have ‘reset’ your profile but you see no change in upload 

As advised , the usual problem cannot be the problem you are having, and it’s not been really established if your device is the bottle neck or not.

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Message 3 of 6

Re: BT fiber 900 - Poor upload speeds (50mb/s~) - Possibly capped?

Hi @0x_0,

Have you had a chance to reach out to the FTTP team as @iniltous suggested?

We can look into your upload for you but it will take us until next week before we can due to Christmas and the two bank holidays. I'll send you a private message in case you need our support.


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Message 4 of 6

Re: BT fiber 900 - Poor upload speeds (50mb/s~) - Possibly capped?

Hi both,

Thankyou for your replies 🙂

@iniltous I will aim to try contact them soon. House is a little manic with Christmas being so close haha 🙂

In the mean time, I can confirm the issue is present on all devices tested. I've tested from my XPS laptop, my desktop and my father's desktop over ethernet (separate cables for each). And all WiFi clients also see the same slower upload speeds. For some bonus points, I've run an iperf test between some of my devices and can get saturated 1gbe upload and download between them, just to confirm everything inside the house is happy.

@DanielS I've replied to your DM. Thankyou for reaching out. As noted I've not had a chance to call through yet. I appreciate things may take longer than usual over the Christmas break. This is not a problem 🙂


Kind regards,


Message 5 of 6

Re: BT fiber 900 - Poor upload speeds (50mb/s~) - Possibly capped?

Just a quick update - I plugged the SH2 back in and disconnected everything else from the network except 1 directly wired desktop to keep over-the-phone diagnostics as simple as possible. A quick speedtest before calling got me 1010/39.

Called through to the FTTP team this-afternoon. They attempted to run a speedtest to the router which failed. A remote reboot was triggered which completed successfully, however they were still unable to trigger a speed test. She said it was giving a generic error each time. They asked what speeds I was seeing, and what websites I was using to get that speed (, and At this point, we ran through some basic Questions & Answers to which she said nothing further could be done over the phone until an engineer had visited to check. And while the engineer is here, they can try to work out why speedtests couldn't be triggered against the router.

I don't expect any updates until the new year, so until then, Merry Christmas and a happy New Year.
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Message 6 of 6

Re: BT fiber 900 - Poor upload speeds (50mb/s~) - Possibly capped?

Further update on this.

Engineer came to visit today. Explained briefly what we were seeing, and why he was called out (because when calling the main fibre support number, they were unable to trigger a speedtest to the SH2 due to 'an error').

He ran a quick speedtest and confirmed the download was fine, but the upload was much slower than expected. He further confirmed that the speedtest to the hub wasn't working for some reason, so he'd go directly to the ONT and used a non-public tool with our landline number to trigger a speedtest and line checks directly to the ONT. Looking at the results, they matched exactly what was being seen from all previous tests.

At this point, there was no further tests that he could perform, and stated that there was probably an issue upstream. Either the wrong package limiting it, or a minor fault upstream. Either way, it was upstream from our house. He said he'll add this to the engineer notes for the visit and that our next steps will be to call up again, and hopefully they'll read the notes and take it from there.

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