g.fast super high sync speed to Smart hub 2, poor download speed

[Packetloss]

Does any BT g.fast customer get download speeds anywhere close to the sync speed? 

I've had variations of g.fast for a couple of years now and I've always suffered from problems with either stability or download speeds.

The first problem that took months to convince BT and Openreach about was the use of an in-line phone filter, as my service was unstable for a year. The connection would drop or the performance would drop every few minutes. This eventually got sorted and BT/Openreach admitted it should not have been installed that way. 

During that time I was convinced to move up to the latest g.fast 330 service, where at best I could never achieve much more than 140Mbps from the Smart hub, where WiFi was disabled and only one device was connected.

So my baseline is:

Downstream Sync speed between 255 and 295Mbps

Upload Sync speed between 35 and 37Mbps

SNR is consistent : 3.7 to 3.9db

I am 104metres away from the Nokia eqipped cabinet. 

All wiring is new and where possible bench tested, with the exception of the new overhead line coming in via the woodpole. 

I've had 4 new Smart hub 2 units from BT. They are running the latest v24 firmware since December 2020.  I routinely reset the router to factory default every 4 to 8 weeks.  None of them make a difference. 

BT have sent out an "expert" who check as much as he could, and also replaced my BT master socket face plate and unfortunately made a mess, so Openreach came out to rectify the mistake. 

After my reset this weekend, and another Openreach visit to tell me my line was fine, I managed to get 150Mbps for the first time when testing from the Smart Hub 2.

I'm beginning to think g.fast is a myth. BT won't offer me any solution other than walking away from the contract. 

My only option is to buy one of the four modem routers that BT used to pilot g.fast and conduct my own testing with my own equipment to see if the limitation is with the Smart Hub 2.

[imjolly]

what speed do you get running this with an ethernet connection

https://fast.com/

[Packetloss]

The results are no different whether I use fast, ookla, or BTs own speed checkers. The download results will vary between 134 to 148Mbps. Only once has it hit 150Mbps.
I have also tried different CAT cables including making up my own in case all the major brand cables I have are faulty despite coming up trumps on my Fluke tester.
I've also replaced the RJ11 cable for a twisted pair equivalent and tested those on my Fluke tester.
As far as Openreach is concerned, they are content that there is nothing wrong with the line or backhaul service, other than the regular random disconnections.
I have bought an Alcatel-Lucent g-240w-g which will arrive by the weekend.  It is a slightly newer version of the four brands that were issused by BT as part of their original FTTC trial.

I was also on the lookout for one of the Huawei MT992 units too.  I'm loathed to buy the new Draytek V166k, but given BT have told me to accept the situation or walk, I might have to try it. 

When this issue was first discussed with BT in 2020, it was escalated to a team in their Ipswich development centre who came back with the answer of "we don't know what's wrong". 

[Studon]

I have the same problem with connexion speeds. I can only attain a max of 148 Mbps down speed in spite of a 250 Mb stayfast guarantee. 

I wonder how many more have the same problem.

I suppose I could "walk away" but I'll have to wait until the a.n. other  company currently installing a fibre network in my locale has completed.

Studon

[Packetloss]

It's interesting that when I was on the g.fast 150 profile, that was supposed to give me a guarantee of 100Mbps on the same line, the best I could achieve was 85Mbps.
My concern is that the 330Mbps performance is more aspirational than a reality, and if perhaps I was 40metres from the cabinet instead of 104metres, I might get improved download speeds, even if the stability is still as flaky as a Cadburys Flake.
BTW, I know I'm 104metres away from the cabinet as the Openreach engineer can show me the measurement from their diagnostic equipment.
Under normal circumstances, I should be seeing download speeds in the range of 220 to 250Mbps, not 130 to 148Mbps.

[bkehoe]

I've had g.fast for well over a year now. Smart Hub 2 never drops sync, synced at the full 330MBit (with attainable 400MBit on approx 130m line) and every single time I do a speed test I get approx 290MBit, plus or minus a couple mbit. 

I presume you're doing your speed tests over ethernet as depending on the wireless speeds your device supports you may not get the full speeds via wifi. 

[Packetloss]

Yes, I am testing over ethernet it was inferred earlier when I mentioned I'd tried different CAT cables.
I'm familiar with most aspects of network design, configuration and performance testing.
All my equipment is calibrated and certified where possible.
I have equipment that with also measure RF interference and electromagnetic interference and the environmental parameters have also been baselined and are well within tolerance.
The only thing I cannot perform is any form of invasive inspection of the Openreach g.fast service and the smart hub cpe.
This is why I'm looking to change the modem and use my own switch to determine whether the root cause is the CPE or not.
I've already tested the performance of the switch ports on the smart hub, and from a LAN perspective it's not the most remarkable bit of kit, but it does provide sufficient throughput capability for the 330 service.