Anyone got talktalk fibre 150 'gfast'? Problem..


Novice Member
Sorry if wrong forum, I'm at the end...

Had fibre 150 installed last Saturday (their new gfast fibre, special gubbins in the exchange - was currently getting 40mbps).

Long story short only getting 88mbps download.

BT Open reach engineer changed wall socket and installed BT gfast modem which sits before the TalkTalk WiFi super router. As below.

In my logic.. If there's 130mbps to the bt modem tested by engineer the weak link is obviously talktalk.

1- my speed is capped
2- the super router (same as on other package) cannot handle gfast

I am waiting for a another new talktalk WiFi router as part of the package but it looks like its identical to the one I've got so don't hold out much hope of it working, if not talktalk said engineer will come back out

Anybody have any ideas?


Last edited:


To rule out issues with the TalkTalk kit, can you connect any PC via ethernet to the back of the modem? You might need to setup a PPPoE connection. Alternatively if you're looking to use your own kit, then I highly recommend the Asus DSL-AC88U router. It has a modem built so you can get rid of the Openreach modem (just keep it as a spare) and its a great router for wifi range and speeds.


Novice Member
Thank you both..

Sorry (was ranting earlier calmed down now lol) the speeds I gave were my daughters laptop connected directly by ethernet to the TT Fibre router

I did then try and connected it to the ethernet port on the BT modem but it did nothing.

I will try your way ref PPPoE (but will need to research)

Great advice on Asus router, if I get no success with new TT router (I know its not going to work) I'll buy that Asus and see what happens. It would be nice only to be using one PowerPoint.

Thanks again, great replies!


Novice Member

Hi ,
I used PPPoE and connected a laptop direct to the BT Opnereach modem, was expecting the 130mbps and got the following which was a shock!?

Checked with 4 speed check websites and the best I got was,,
56.2 download
31.4 upload

I dont know if this would have affected my test. the ethernet cable from the bt modem was connected to the laptop via a CAT5 Ethernet to usb adaptor because the laptop didnt have a native ethernet port.

i checked the ethernet port details and it was as follows.
Connection spedd 1.0 gbps
Activity bytes
sent 122,075,077
recieved 211,444,145

this puts a new spin on things as I was hoping I could show talktalk i was getting the 130mbps that the engineer had before he left.

so does this mean talktalk have throttled it right down?

or problem at the exchange?

the new talktalk router should be here soon so ill stick that in but its obviously going to give the same speeds, then the engineer will be arranged!



Distinguished Member
Just to clarify the installer showed you the higher speed?

If so suggests an issue with laptop and you need to try another device.

Did you try Sam knows or dslreports for the speed test?


Novice Member
I didn't try either of them websites.

The openreach engineer showed me 130 speed when he connected.

I'll try another device but do you think it's that?


Novice Member
No router was sent out! But an engineer is coming out because of..

"I will need to arrange an engineer to investigate this at the property as this is something we cannot fix over chat. The router isn't the issue. There is a stability issue identified on the line which may cause the drop in speeds"


Distinguished Member
Ah hopefully that's the cause, which is a bit rubbish for you but at least you know. I would try with another machine just in case if you have one. Speedtesting can be fickle at the best of times though :)


Novice Member
Valid point lol... But addition to the above... Just did a wifi speed check on my wife's iPhone (8) s daughters (7) both got over 140mbps download via ookla website.

Tried on my P20 lite, got 47mbps...obviously cheaper hardware in the phone?

Will double check the laptops and login direct to bt modem, trouble is neither has a built in ethernet port I have a USB to Gigabit adaptor.

Just ran a test, laptop via said adaptor direct into BT Modem.
41mbps download!??

Non of this is making sense (I'm no expert)

So apparently unstable line but...

2 x iPhone getting 140mbps (fantastic)

1 x crap p20 getting 40mbps

House PC Gigabit Ethernet connected to Gigabit hub connected direct to talktalk router 67mbps

Direct check to BT modem 41mbps

I know there ares so many variables here

I'm lost lol


Distinguished Member
Using a USB/ethernet adapter is of course adding "another thing" with it's own complexities. USB 1 & 2 stand no change of running at gigibit. You'd need USB 3 (in both the port and the adapter) and of course the host bus and OS would need to be capable of driving it that hard.

A subtlety that is often overlooked when people get into the data networking "numbers game" is that the equipment cites performance in a metric called "Link Rate" (or DataLink Rate or Layer 2 Rate) whereas when people "talk" about "speed" and try to measure it using Speedtest and the like, they are talking about something else called "throughput." The two are both expressed in "bits per second" but they are not at all the same thing, in the same way that instantaneous "velocity" and "average speed" of a car are both expressed in km/h but they also are not the same thing.

Data networking Link Rates are not some theoretical measure of "capacity" (even WIkipedia gets this wrong,) they are a statement of "time" expressed as a ratio. A link rate expresses how long it takes to transmit 1 bit, not how many bits can be transmitted in an arbitrarily chosen unit of time.

Thusly, a link rate of 10 bps mean "it takes one tenth of a second to transmit 1 bit" NOT "you can send 10 bits every second." It just so happens that we choose to express it as a ratio based on a prticular unit of time (whole seconds.)

Virtual all data network technologies do not transmit continuously, they are "bursty." Some bits get sent, then silence, then some more bits, then silence and so on. If you were to run a "speed test" you see an average value, which factors in the the silent periods, Link Rate does the opposite and only expresses the time taken to transmit 1 bit when those bits happen to be in flight.

The time to transmit 1 bit is a precise measure - which is why it's always been used "in the business" - averages (such as computed by speed test) are subject to the vagaries and variations causes by different length bursts, different length silent periods and so on which make them much more variable. Not to mention the various "protocol overheads" which differ between technologies and traffic competition which all make "speed test" "indicative" at best.

So amongst data networking professionals data networking Link Rates are something we use more or less as a "label" rather and then anything we sweat over in order to ensure link X is "just so." We use speed tests (in the knowledge of all the protocol overheads and other factors) as a sort of "wet finger" test to ensure a link is in the right ballpark, but again we don't stress over the numbers.

So, for example, being orders of magnitude out would get our attention, but, let's say, speedtesting a 100mbps ethernet link at 90mbps would not be getting us excited as it's "about right."

To test your ISP link, you need to remove as many other complicating factors as possible, hence the guys are advising you to use something we know is very reliable and efficient (ethernet) and avoid using WI-FI, powerlines, USB/ethernet adapters and so on. Such are complicating the investigation as they introduce their own variances. And the more of them we have in the test path, the more "things" there are that could be complicating factors.

It's also worth mentioning that not all routers are equal. IP routing is a relatively simple but not trivial computing task and any router has to be "sized" to be able to cope with the amount of traffic it expects to handle. Routers effectively have RAM and a CPU inside them, like a PC, and they need to be "fast" enough to cope with the anticipated load. So a router "sized" for little 8mbps ADSL link probably would not have a horsepower to cope with a 200mbps FTTC link and so on. (The metric is called "WAN-To-LAN Routing Capacity.") This is why ISP's often send you a new router when you upgrade your package - your old one may not have the grunt for the upgraded line.

A US web site called SmallNetBuilder often tests router WAN-to-LAN routing capacity when he tests kit. You might take a look there and see if he's ever tested your router and what results he got.
Last edited:

Similar threads

The latest video from AVForums

Podcast: New TVs, Samsung Q800T Soundbar review, IFA latest, Movie and AV News, B+W Brad Pitt
Top Bottom