Full Fibre -Speeds all over the place

Had BT full fibre installed approx 4 weeks ago, I am on the 300mbps package

First two weeks it was lovely 300mbps, 37 MB downloads, since then very different picture, upload has remained consistent throughout but download keeps reverting to anywhere from 65mbps to 89mbps, on the odd occasion it will then go back to 301 mbps.

Had Open reach out twice, got a third visit tomorrow, so far ONT replaced and the SMARTHUB 2, surely the problem is the external cabling, profile or at the exchange itself
Any ideas from here before I get the run around again tomorrow from openreach

Provide information on your testing setup please.
1. Is this tested using a wireless or wired connection?
2. Have you tested with a machine directly connected to the ONT - no router or SH involved in the connection. Note you will need to setup a PPPoE client directly on the machine attached to the ONT to make this work.
3. What is the spec. and approx. age of PC and what operating system are you using to test with.
4. Are you running any AV or spam protection software?
5. Finally do you have you access to another machine(s) to test with?

1) Wired direct connection to router with everything else removed
2) Not yet - Will try this if still the same by end of week
3) AMD 2700X 32MB RAM 3080 RTX WINDOWS 10
4) Only the standard windows defender stuff
5) Tried on a [censored] laptop, 100% same results


I can sit here and spam F5 on a speedtest site and get 85 on average 19 times out of 20, then on the 20th might say 301, rinse and repeat

Edited by deleted (Tue 15-Jun-21 12:16:43)

On top of Pheasant’s good advice …

If a profile was the issue as you suggest, then throughput speeds would consistently hit that profile, not wander about.

If the external cabling was borked it would either work, or wouldn’t work.

The issue is most likely either your kit, as Pheasant covers, or congestion from the head end going back.

Make a direct connection to the ONT, and use fast.com for speed tests, this is the speed test they like to see results from

This all started when my neighbour was connected as well (We are on pole not ducts), I can't see how its my kit, for example when connected to my wider network to my switch the xbox will work at 37.5 MB download when all is good, when its back to 85mbps then it reduces significantly.

For it to be my kit it would need to be the router (replaced), ONT (replaced), laptop (Yeah its [censored] but capable of 300mbps), my pc (Any excuse to upgrade would be good ) , XBOX Series X



In short, got to be outside the premises

They (BT) have done checks their end and are seeing the 85 ish speeds as well, hence why a third engineer visit

There is a reason ISP like fast.com can give nice and high results well beyond what is possible over TCP/IP layer and its use of Netflix CDN means for a big ISP will often be on-net

It was the fibre you would have no connection i.e. FTTP is link at full 2.4 Gbps or nothing.

Needs you to post some links to the shared results from https://www.thinkbroadband.com/speedtest

I'll update a speedtest run on the main site, just tried

fastnet, 93mbps
ookla : 94mbps
bt wholesale: 90mbps
broadbanduk: 92mbps