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DariusA
Aspiring Contributor
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Message 1 of 24

Disconnection issues and extremely slow speeds

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We have been experiencing slower speeds and some occasional disconnects with our Home Hub 5 for a little while. This seemed to get worse towards the end of last week - at one point I was disconnected three times during the course of an hour while trying to talk on a Google Hangout. As a result, over the weekend I tried some of the methods suggested to fix connection issues, which included restarting and resetting the router. By Sunday, I figured out that this was probably a bad idea as I learned that repeated disconnects like this can simply result in the connection being placed on a banded profile.

 

The speedtest results from the speedtest.btwholesale.com tester certainly indicated that the connection was being artificially limited, with an IP Profile of 0.25 Mbps and upload speeds actually slightly higher than download speeds. From reading around it seemed that the only way to get taken off banded profiles was to let the connection stabilise and that it would automatically improve over 3-5 days.

 

Unfortunately, the disconnections didn't stop and the hub has disconnected at random points at least twice during the course of the week. It managed over three full days of connection between Tuesday night and last night, but when I checked this morning it had again disconnected itself during the night. Not only do I not know why this is still happening, I also assume that this is preventing the banded profile from being lifted.

 

The line in the event log that shows up explaining the disconnection is "PPP LCP Send Termination Request [User request]", which from reading around here seems to be a result of BT trying to make configuration changes to the hub.

 

I have also since tried the line noise test by plugging a phone directly into the master socket, and couldn't really hear anything between the messages. The noise margin seems on the low side from what I can work out but I'm no expert with these. Similarly, I have run the speed test again and while the IP Profile has changed very slightly to 0.31 Mbps, that's still obviously giving me incredibly slow speeds, and the tester doesn't seem to think there is anything wrong.

 

Can anyone tell me if these results and router stats indicate a specific issue that needs to be fixed? I believe I have tried everything I can do here to diagnose and/or fix problems and none of them seems to have worked. If it was simply a case of leaving the connection until the banded profile was lifted, I'm not sure how that's going to happen if the router disconnects of its own accord every two or three days.

 

Screen shot 2017-06-10 at 14.29.47.png

 

3. Firmware version:Software version 4.7.5.1.83.8.204.1.11 (Type A) Last updated 17/06/15
4. Board version:BT Hub 5A
5. DSL uptime:0 days, 03:12:14
6. Data rate:373 / 357
7. Maximum data rate:476 / 908
8. Noise margin:8.1 / 9.2
9. Line attenuation:33.5 / 45.9
10. Signal attenuation:33.0 / 48.9
11. Data sent/received:3.0 MB / 12.6 MB
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23 REPLIES 23
john46
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Message 2 of 24

Re: Disconnection issues and extremely slow speeds

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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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DariusA
Aspiring Contributor
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Message 3 of 24

Re: Disconnection issues and extremely slow speeds

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So the fact that the connection is being broken by these PPP LCP termination requests won't affect how long it takes to get off the banded profile? I haven't reset the router all week and the fact that there's been no change in the profile made me wonder if that would leave us stuck at this speed. If there's nothing indicative of a more fundamental problem then I'll continue to leave it alone and hope it gets better!
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john46
Distinguished Sage
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Message 4 of 24

Re: Disconnection issues and extremely slow speeds

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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
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DariusA
Aspiring Contributor
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Message 5 of 24

Re: Disconnection issues and extremely slow speeds

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Yes, I've tried that and couldn't hear anything on the line.

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john46
Distinguished Sage
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Message 6 of 24

Re: Disconnection issues and extremely slow speeds

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as I posted it needs a stable connection and your speed should start to increase after 10 day but being so low up to a month to fully recover
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DariusA
Aspiring Contributor
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Message 7 of 24

Re: Disconnection issues and extremely slow speeds

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So I've waited a month and while the speed has increased very incrementally, the IP profile on the line is still just at 1.15MB and clearly hasn't made it back to full speed, making many things unusable. Is it going to get any better than this or are we stuck at this speed now it's been a month?

 

We are now also getting constant messages on the event log suggesting a TCP reset attack starting like this: " OUT: BLOCK [9] Packet invalid in connection (tcp reset attack is suspected"

and then followed by "IN: BLOCK [9] Packet invalid in connection (Invalid tcp flags for current tcp state: TCP". I've seen posts saying this is just the firewall doing its job but is it really normal for that to be happening every time any traffic passes through the router?
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NeilO
Moderator
Moderator
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Message 8 of 24

Re: Disconnection issues and extremely slow speeds

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@DariusA We'll be happy to look into this further if you send over your details on the 'click here to contact the mods' link in my forum profile. You can find the link by clicking on my username.

 

The block TCP blocked packet messages are normal and nothing to worry about as you've seen it's the firewall blocking unauthorised access to your Hub. 

Thanks

Neil 

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DariusA
Aspiring Contributor
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Message 9 of 24

Re: Disconnection issues and extremely slow speeds

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Hi Neil,

 

I can't see that link appearing anywhere on your profile - I've searched the page several times now and only the regular BT contact pages are appearing, nothing about contacting the moderators. Is there something I'm doing wrong?

 

Thanks,

 

Darius

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JohnC2
Moderator
Moderator
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Message 10 of 24

Re: Disconnection issues and extremely slow speeds

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Hi @DariusA Sorry about that. I have enabled the link for you under my profile. You will see a click here to contact the mods hyperlink just below my Avatar.

 

Ps you will not see the link on the mobile view setting. 

 

Cheers

John

 

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