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Message 1 of 6

ADSL connection very slow, keeps dropping

As in title my adsl broadband is very slow and connection keeps dropping. I am connected to test/master socket using a HomeHub3.

Line info as below:

Speed test:

1. Best Effort Test: -provides background information.

Download Speed
0.91 Mbps

0 Mbps 1 Mbps
Max Achievable Speed

Download speedachieved during the test was - 0.91 Mbps
For your connection, the acceptable range of speeds is 0.4 Mbps-1 Mbps.
IP Profile for your line is - 1.01 Mbps

2. Upstream Test: -provides background information.

Upload Speed
0.12 Mbps

0 Mbps 0.83 Mbps
Max Achievable Speed

Upload speed achieved during the test was - 0.12Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps

Post your Home Hub router stats

ADSL Line Status
Connection information
Line state: Connected
Connection time: 0 day, 00:29:56
Downstream: 1,152 Kbps
Upstream: 440 Kbps

ADSL settings

VPI/VCI: 0/38
Type: PPPoA
Modulation: G.992.5 Annex A
Latency type: Interleaved
Noise margin (Down/Up): 24.4 dB / 6.3 dB
Line attenuation (Down/Up): 8.5 dB / 4.6 dB
Output power (Down/Up): 0.0 dBm / 12.8 dBm
FEC Events (Down/Up): 0 / 6244
CRC Events (Down/Up):
0 / 365

From event log:

9:58:19,06 Mar. WAN connection WAN1_INTERNET_B_ATM2_0_35 connected.
19:58:18,06 Mar. DSL Link Up: Down Rate=1152Kbps, Up Rate=440Kbps; SNR Margin Down=28.4dB, Up=17.6dB;
19:57:31,06 Mar. WAN connection WAN1_INTERNET_B_ATM2_0_35 disconnected.[ERROR_NO_CARRIER]
19:57:29,06 Mar. PPP LCP Send Termination Request
19:57:28,06 Mar. WAN connection WAN3_TR069_INTERNET_R_ATM1_0_38 disconnected.[ERROR_NO_CARRIER]
19:57:28,06 Mar. DSL Link Down:the duration is 359 seconds [1 : LosDetector]
19:51:36,06 Mar. WAN Auto-sensing detected port DSL
19:51:36,06 Mar. WAN Auto-sensing last connection port: DSL
19:51:34,06 Mar. WAN connection WAN3_TR069_INTERNET_R_ATM1_0_38 connected.

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Message 2 of 6

Re: ADSL connection very slow, keeps dropping

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.
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Message 3 of 6

Re: ADSL connection very slow, keeps dropping

Is there any noise on your phone calls? Dial 17070 and select option 2, there should be no noise between the announcements.


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Message 4 of 6

Re: ADSL connection very slow, keeps dropping

Hi @jdgala,


Welcome and thanks for posting. Your noise margin is very high at 24db. Is there any noise on your line? Can you check that as pr @Keith_Beddoe post?





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Message 5 of 6

Re: ADSL connection very slow, keeps dropping

thanks for reply.


Tried a noise test, only have a cordless phone and I can hear some noise on the line. Can this be escalated via this forum or shall I call BT?



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Message 6 of 6

Re: ADSL connection very slow, keeps dropping

What sort of noise is it, is a cracking noise?


You would need to prove whether the noise is being caused by something inside or outside,


Can you please connect things up as shown below, and see if the noise is still there.



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