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Message 1 of 7

Capped speed after engineer visit/Connection drop out



I had been having problems with my broadband speed over the last few months, did the fault checks, used ethernet cable instead of wireless and no fixes. The speed did not improve and the connection regularly dropped out/reset.


I called BT and they sent an engineer on the 29th March. He said the line was fine and no noise present. He stated that the speed would improve over the next few days.


Now three weeks later, the speed has not improved and the connection has been continuing to drop out every few days. This is the first time I have had a stable connection over 3 days.


I'm not sure if its just the speed cap causing the issue, but why would the connection continue to drop?


Any assistance will be much appreciated





  1. Best Effort Test: -provides background information.

Download  Speed 2.64 Mbps

Max Achievable Speed 4 Mbps

Download speedachieved during the test was - 2.64 Mbps
 For your connection, the acceptable range of speeds is 1.2 Mbps-4 Mbps.
 IP Profile for your line is - 2.71 Mbps


  1. Upstream Test: -provides background information.

Upload Speed 0.88 Mbps

Max Achievable Speed 0.83 Mbps

Upload speed achieved during the test was - 0.88Mbps
 Additional Information:
 Upstream Rate IP profile on your line is - 0.83 Mbps



1. Product name:

BT Home Hub

2. Serial number:


3. Firmware version:

Software version (Type A) Last updated 31/10/16

4. Board version:

BT Hub 4A

5. ADSL uptime:

4 days, 00:21:07

6. Bandwidth:

1160 / 3069

7. Data sent/received:

1.2 GB / 9.8 GB

8. Broadband username:

9. BT Wi-fi:


10. 2.4 GHz Wireless network/SSID:


11. 2.4 GHz Wireless connections:

Enabled (802.11 b/g/n (up to 144 Mb/s))

12. 2.4 GHz Wireless security:

WPA and WPA2

13. 2.4 GHz Wireless channel:

Automatic (Smart Wireless)

14. 5 GHz Wireless network/SSID:


15. 5 GHz Wireless connections:

Enabled (802.11 a/n (up to 300 Mb/s))

16. 5 GHz Wireless security:


17. 5 GHz Wireless channel:

Automatic (Smart Wireless)

18. Firewall:


19. MAC Address:


20. VPI/VCI:

0 / 38

21. Modulation:

G.992.5 Annex A

22. Latency type:


23. Software variant:


24. Boot loader:


0 Ratings
Distinguished Sage
Message 2 of 7

Re: Capped speed after engineer visit/Connection drop out

Hi Welcome to the community forums

Have you tried the quiet line test dial 17070 option 2 you should hear no noise if you can hear noise then it needs reporting to BT faults on 151 with no mention of broadband
in the call are you connected to the test socket using a new filter

if using a hub 4 locate these lines located in the hub logs
Lines should look like this
19:11:29, 07 Nov. (2290101.460000) DSL noise margin: 7.00 dB upstream, 6.10 dB downstream
19:11:29, 07 Nov. (2290101.390000) DSL line rate: 448 Kbps upstream, 288 Kbps downstream

The stats for the Home Hub 6 can be found on the Information page from then Advanced Settings -> Technical Log. 

Can you run this checker and post back a screen shot of the results. Make sure you delete your phone number before posting.

Can you use this speed tester then carry out the further diagnostics and post back a screen shot of all the results including your IP profile for up and down.

This test must be done with a wired connection.

once you have posted the information asked for then the community members can help you more

Thank You
0 Ratings
Message 3 of 7

Re: Capped speed after engineer visit/Connection drop out

Hi John,


Thanks for the quick reply. Quiet line test done, no noise, engineer did that already. It was done through the test socket and engineer said the filter was fine.


Info from the hub log:

11:03:44, 17 Apr. (105.080000) DSL noise margin: 5.90 dB upstream, 26.40 dB downstream
11:03:44, 17 Apr. (104.170000) DSL line rate: 1160 Kbps upstream, 3069 Kbps downstream


DSL Checker:



Speed Test:



Tests were all done from computer using Ethernet cable. Having to post from phone as can't get onto the forum on the computer.




0 Ratings
Distinguished Sage
Message 4 of 7

Re: Capped speed after engineer visit/Connection drop out

Why has my speed suddenly dropped?
ADSL connections (see notes about Infinity at the end), and the notes by RogerB
Changes in your connection speed are automatically managed by the exchange equipment, using a process called
Dynamic Line Management (DLM).
Its purpose it to give you the best speed possible, without introducing a lot of errors back into the BT network.
These errors impact on other users, and can slow their connection down, as your data packets have to keep being resent.
This is a continous process, but certain things can cause it to make drastic changes to your connection speed.

These can include the following:-
You could have also been recently moved from ADSL max to ADSL2+, this would mean that the line
would have to re-train again, and must be left undisturbed  for at least 10 days.
If you keep restarting or disconnecting your BT Home hub, then the exchange equipment will see this as a fault condition, and reduce your connection speed, in an attempt to stabilise your line.
You have recently had a fault on your line which has just been fixed.

Sometimes a single interruption to your line can cause this too, especially if it generates a large error burst.
The effect is that you get placed in a low banded speed profile, and you will notice that your downstream margin is high, usually over 15dB.
The lower the banded speed profile, the quicker it will recover, but it could take up to a month before the fullspeed is recovered.

If you want your speed to recover, then these are the steps you need to take.
DO NOT restart or disconnect the power to your BT Home Hub.
DO NOT disconnect your BT Home hub from your phone line.
Leave everything alone for at least 10 days, so that the exchange can record a stable connection.

During this time, the exchange may drop the connection, and re-establish a faster connection.
If you use the BT Speedtester, then do not restart the BT Home Hub, even if it tells you to.
If after 10 days your speed does not increase, then please return to your forum post.
showing  that you have 10 days of connection time, then the problem can be escalated.

You can calculate your final speed by using this website.

Maximum speed calculator
Infinity connections
A similar process is applied to the connection between the Infinity cabinet, and the Openreach modem.
You cannot view that connection information, but the same thing applies, do not restart or disconnect the Openreach modem.
The BT home hub only acts as a router, and restarting it will not affect your physical connection speed to the cabinet.
Additional information by forum member RogerB
BT broadband is line adaptive, if you have a good line, you get good broadband , BUT consider this, you only get good broadband
from the outset, if you let the exchange "train" the connection, when it is new, simply because it has to try various methods of modulation.
And once it is running at full speed and set the MSR (maximum stable rate) provided you don't keep disconnecting the router, it will stay that way.
So two important things:  ALWAYS leave the router on, 24/7 and DO NOT impede the training process which can take up to 10 days.
The reasons are vaguely the same for both scenarios:  DLM trains the connection during setup, and DLM runs the connection in a similar but different mode once it's running.
And the most common issue apart from line faults in causing poor broadband is FREQUENT RESETS and DISCONNECTIONS of the router or hub, because if you interupt line management it will demote the line profile if done to excess, with often time consuming efforts and long waits to get it back.
BT don't punish users indiscriminently by making them wait for their broadband speed to come up, but the line management is in place  to DEFEND the network against bad and corrupted data, and if the exchange sees your line being reset too often it assumes a fault,
whereby your linespeed is demoted, and often profoundly so.
Also, because the exchange can't tell the difference between you messing around resetting all the time, and a real line fault, it assumes (using logic) the worst and demotes the line profile.
If you get a real line fault and the noise margin increases, the linespeed will decrease, it's normal, again it's a defence to help give you a service  allbeit a depleted one, and at the same time stop corrupted data getting back to the exchanges.
But unfortunatlely it's at this point when people in general start to become frustrated,  and guess what?
They then start to reset the router in an attempt to "repair" the connection. And in doing so, impede the line management from promoting the linespeed again. (providing any fault is or was fixed).
And to summarise, if the connection is left to run unimpeded, no excess resetting, and left to its own devices, it actually benefits from the good line

history that the exchange has accumulated for your connection, simply because the attention span by the line management is not so profound when it does bite the dust, for whatever reason.
So regardless of the opinions of some, switching off broadband routers is NOT a good idea, not if you want consistent broadband and a good line rate.
0 Ratings
Message 5 of 7

Re: Capped speed after engineer visit/Connection drop out

John, thank you for your reply.


I am well aware of the problems of the user continuing to reset their router and problems with speed that this causes. My mention of the problem with the connection resets was not me stating that I was resetting the router, but a problem I was having with the router.


I can assure you the only time the router has been reset in the last month was when the engineer attended. I have not reset the router since this time, being the 29th March, as mentioned. 


Also as I stated, I waited to post due to reading other users threads, the mods need to see 3 days of stable connection before they will look at the issue. I currently have 4 days stable connection and the router has been on for 23 days. 


Why now the wait for 10 days? And waiting isn't stopping the connection from breaking in the meantime, meaning I would need to wait again, if I ever get to a 10 day stable connection.


Many thanks,


0 Ratings
Distinguished Sage
Message 6 of 7

Re: Capped speed after engineer visit/Connection drop out

you have a banded profile which needs to let the DLM do its job if your line is unstable which it appears to be there is no point in resetting it as you will just go back into the banded profile again within a few days stability is vital first
0 Ratings
Distinguished Sage
Message 7 of 7

Re: Capped speed after engineer visit/Connection drop out

the fact your router has been powered up 24 days does not apply it is the DSL up time that is important

If the mods get involved once they post their contact link once you have replied to it can then take a further 3/5 working days (excluding weekends ) by which time your connection should have recovered automatically
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