Broadband Availability Checker

Good Afternoon,

How accurate do people generally find the estimated speeds on the
Broadband Availability Checker website - https://www.broadbandchecker.btwholesale.com/#/ADSL

The website gives estimated download speeds of 20-40mbps for my line using my telephone number.

In reality, I can only achieve 13-18mbps download. This is the speed I get with my current provider (Plusnet), plus the following providers (if I try to sign up with them) EE, BT, Utility Warehouse, Talk Talk and COOP all give speed estimates in this range with a minimum guarantee of 15mbps.

I have had an Openreach engineer visit who confirms no fault on my line.

My line is 1.2km from the cabinet I am connected to. The cabinet was installed right next to the exchange.

Is it likely at this distance I would be able to achieve up to 40mbps?

Thanks in advance for any feedback or input.

On a perfect line at 1.2km, I would guess at around 25Mbps and that could depend on the gauge/type of conductors. You might just scrape 30Mbps in some cases if the target SNR drops to 3dB but nothing more.

Add in external noise, cross talk, joints, an imperfect filter (none are perfect), the tolerance on modem front end and the achievable number drops.


Your 13-18 is maybe a little low, however, one nasty crosstalker can easily knock 5-8 Mbps from your speed. How accurate is the 1.2km is that actual wire length or your guestimate based on where you think it runs?

Tidying up at your end might give a little more, or it might not!

What are your full line stats?

Thanks for the reply.

The line length and location of cabinet were provided by the Openreach engineer and he explained how the line went round the village until it arrived at my postcode.

These are the full stats from the availability checker

Featured Products Downstream Line Rate(Mbps) Upstream Line Rate (Mbps) Downstream Handback
Threshold(Mbps) WBC FTTC Availability Date WBC SOGEA Availability Date Left in Jumper
High Low High Low
VDSL Range A (Clean) 42.9 27.4 8 6.1 25 Available Available --
VDSL Range B (Impacted) 41.8 25 7.8 5.4 20 Available Available --
Featured Products Downstream Line Rate(Mbps) Upstream Line Rate (Mbps) Downstream Range (Mbps) Availability Date FTTP Install Process
FTTP on Demand 330 30 -- Available --
ADSL Products Downstream Line Rate (Mbps) Upstream Line Rate (Mbps) Downstream Range(Mbps) ADSL Availability Date WBC SOADSL Availability Date Left in Jumper
WBC ADSL 2+ Up to 10.5 -- 8 to 12.5 Available Available --
WBC ADSL2+ Annex M Up to 10.5 Up to 1 8 to 12.5 Available Available --
ADSL Max Up to 8 -- 7 to 8 Available Available --
WBC Fixed Rate 2 -- -- Available Available --
Fixed Rate 2 -- -- Available -- --
Observed Speeds VDSL ADSL
Max Observed Downstream Speed 19.99 18.92
Max Observed Upstream Speed 5.96 1.13
Observed Date 2021-02-01 2019-02-24
Other Offerings Availability Date
VDSL Multicast Available
ADSL Multicast Available
Premise Environment Status
Bridge Tap N
VRI N
NTE FacePlate N
Last Test Date 28-01-2021
Exchange Product Restrictions Status
FTTP Priority Exchange N
WLR Withdrawal N
SOADSL Restriction Y

What about the stats from you modem/hub?

Apologies - is this what you meant?

6. Data rate: 5921 / 19135
7. Maximum data rate: 5921 / 32197
8. Noise margin: 6.2 / 13.8
9. Line attenuation: 28.2 / 26.1
10. Signal attenuation: 27.9 / 23.7

26dB suggest a little less than 1.2 km and the max rate of 32Mbps suggests that there are other issues given your 19Mbps sync.

What do you have connected at home as the difference between Max and Actual is significant. The 13.8dB suggests it is syncing low because there is an issue somewhere.

You've got a high downstream noise margin - that potentially suggests there has been instability on the line that it has resolved by increasing the noise margin. If DLM is being allowed to do its thing then it should try reducing noise margin if the line is stable and doesn't have masses of errors - it may have already tried that and it not worked.

What happens if you reboot the router and check the SNR as soon as it is rebooted? My guess is it might be 12dB at that point which is probably your current target SNR.

Can you get any info from your router on errors as that might also help in understanding the line characteristics?

Edited by ian72 (Wed 10-Feb-21 16:18:11)

Sorry looked back through my records and I found the estimate I was given by Plusnet for the line length - it is 1.1127km

My set up is one master socket. No other sockets or extension leads. Router is plugged directly into the socket. Face plate was replaced by engineer so filter no longer needed. Phone connected is not digital or cordless. Router is the one provided by plusnet.

I have two devices connected by ethernet (laptops) and everything else is via Wifi (SkyBox, 2 TVs, Playstation plus 2 phones and Ipad)

Can I suggest that you disconnect the modem/router from the socket.

Then reboot it. Wait 30 minutes before going to te stats page - which will be blank without a connection. Then disconnect the phone.

Finally, plug the modem/router in, and as soon as a full set of stats are there grab a copy and another copy a minute or two later.

Post those here, and then plug the phone in - do the stats change significantly.


Also, if you have a high SNR you need to leave everything alone to allow it to stabilise and reset.

In reply to a post by marko845:

Apologies - is this what you meant?

6. Data rate: 5921 / 19135
7. Maximum data rate: 5921 / 32197
8. Noise margin: 6.2 / 13.8
9. Line attenuation: 28.2 / 26.1
10. Signal attenuation: 27.9 / 23.7

Can you provide the cabinet number and exchange that's reported at the top of the results page on the availability checker.

What modem/hub are you using?

The line doesn't look banded/capped by the DLM.

It could possibly be a Vectoring issue. Vectoring issues often result in a low downstream sync and high noise margin.
That's only possible if you are connected to a BDUK funded Huawei cabinet.
That can be checked using the cabinet number and exchange or if you would rather not give that info I could explain how to check this yourself.

Ideally your line will sync around the maximum data rate reported by your modem.