Help troubleshooting BB, please ;)

AMG

AMG

AMG

Soldato
Joined
18 Aug 2008
Posts
4,700
Location
lincs, spalding
Hello OCuk

Long story short, I am with BT or my parents are..and of late its been dail up slow and I can not do a thing about it.

I have tested it in the test socket in the master socket, no change, done silent tests and it seems normal( the normal quiet electronic hiss) I am at a loss, it can't be the houses wiring (again) as the test socket does the same, I have replaced the ADSL filter, no change...so what can it be?

here is the stats for currently on the BT home hub 2.0 ( when BT stop mucking about with it)

Line state Connected
Connection time 0 days, 0:26:48
Downstream 283 Kbps
Upstream 446 Kbps

ADSL settings
VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5
Latency type Interleaved
Noise margin (Down/Up) 34.6 dB / 20.1 dB
Line attenuation (Down/Up) 18.5 dB / 9.4 dB
Output power (Down/Up) 20.9 dBm / 12.2 dBm
Loss of Framing (Local) 0
Loss of Signal (Local) 0
Loss of Power (Local) 0
FEC Errors (Down/Up) 0 / 0
CRC Errors (Down/Up) 0 / N/A
HEC Errors (Down/Up) N/A / 0
Error Seconds (Local) 0

The Noise margin did go right down after I phoned up bt but they went back up over night :(

I dunno what else to do short of getting another router/hub to use than it might not sort out this issue

**Edit**

Before anyone asks :P



Cheers for your time.
 
Last edited:
Ok, so you're in the test socket already? Have you changed the Filter? If not, do so. If you have then it's either your Router (unlikely but try and test another if you can get your hands on one) or there's a problem on the line. Get back onto BT and INSIST on an Engineer as those stats just ain't right Son, it just ain't right I tells ya!
 
Yeah I did do that, no change as stated, but no harm in trying it again
 
With an attenuation of 18dB you should be to rocking a near to full speed connection of near 20 Mbit.

Your noise margin is basically excessively high to compensate for something untoward on your line.

Do the attenuation or noise margin figures fluctuate at all when plugged into te test socket?

You mentioned the noise margin went down at some point. Did the connection speed increase? Did you get more errors? Loss of signal?
 
Last edited:
Thank you for the replies.
I m sorry I did forget to mention my bb seems stable, if it was not for the hub restarting all the time cos bt are messing with settings at least I know they are up to something but, its not really improving anything :x

There was hardly a change in both speed nor noise DB it all remind the same or close to the same as on the master ( its now back on master cos there was not point in keep it on it)

Yes the noise margins did change after I reported the fault to BT, the noise margin dropped off to sub 20 Db but no change in speed ethoir download noir up load I do have a basic screen capture of that, but not off errors I m sorry to say. In the morning it went back up to 36Db again. with no change of speed.

the noise margin does change after a while it comes down to about 30 but than Bt remotely restart the hub.

I have a uneducated guess that it could be my hub on its way out, but I don't want a BT tech to come cos that costs money which can be avoided. If I do find out its the hub bt will have to give us a new 3.0 one anyhow. But at the same time I don't want to waste money replacing another bit of equipment that is still perfectly good. But on the other hand they are not too expensive but I dunno :s

have a good night chaps
 
Last edited:
It looks like BT have throttled the line to keep it stable. You need to call them and perform an SNR reset and that should sort your problem (if its not hardware based)
 
Considering SNR would normally be around 5-10dB on an ADSL2+ line I agree that something has been going on with your line to cause it to settle at such a high SNR and low resulting sync speed.

The ping by itself could just be BT throttling the connection during peak periods. You'd need to retest for ping at different times of the day.

Your modem may not be helping but I find it hard to believe that it could be that bad at holding onto an ADSL signal that it has to drop 18 Mbit off your speed and see a few hundred times more signal to noise ratio to be stable.

If you were to run 'routerstats' or 'routerstatslite' all day and night you might be able to establish some trends. I had to run the program for a few days to notice the issue I had with my line.

What tends to happen with noise peaks on the line is that the CRC or HEC errors will suddenly increase, SNR will drop to lower levels and you may even lose sync. If this happens repeatedly the exchange will reduce your sync.
 
The mods on the BT forums are very helpful - if you sign up to the community you can ask them for help via this form.

It may take a couple of days of but they can get right to the heart of the matter allowing you to cut through all the usual BT faff.
 
Hi there I have done, however I can't use that method as it will cause more issues as I have phoned up bt..
Bt are starting to suspect the hub ( its getting quite old as we got it in 2010 time if I remeber right.) anyway BT wish to send a engineer to me to investigate the problem from my end.

Okay update its now in test socket

ADSL line status


Connection information



Line state

Connected



Connection time

0 days, 1:01:47



Downstream

283 Kbps



Upstream

447 Kbps




ADSL settings



VPI/VCI

0/38



Type

PPPoA



Modulation

ITU-T G.992.5



Latency type

Interleaved



Noise margin (Down/Up)

34.6 dB / 21.4 dB



Line attenuation (Down/Up)

18.5 dB / 9.4 dB



Output power (Down/Up)

20.9 dBm / 12.4 dBm



Loss of Framing (Local)

12



Loss of Signal (Local)

2



Loss of Power (Local)

0



FEC Errors (Down/Up)

0 / 0



CRC Errors (Down/Up)

0 / N/A



HEC Errors (Down/Up)

N/A / 36532



Error Seconds (Local)

2

There we go

cheers for your input

Sorry if my spelling and grammer is out im on my lumia
 
LOS - Loss of Signal

An alarm state process, different routers may have different alarm periods. A typical alarm integration period may be 2.5 seconds with a 10 second deactivation period.

A LOS defect may initially be triggered when all zeros are received for 20 microseconds which starts the integration period. During the integration period, 2 consecutive frames with 20 microseconds of signal loss will record a LOS event.
The LOS alarm will clear when no LOS defects are detected within the deactivation period.

A couple or so LOS events may go totally un-noticed during bursty activity such as web-browsing etc. The connection should be able to cope with this momentary loss of signal with the exchange, however a high level indicates a noise problem.
Click to expand...


HEC Errors - Header Error Check/Correction

Count of HEC Errors. HEC is a type of CRC error check which has been performed on the header of an ATM cell, but 1 bit errors can be corrected. This count is usually where HECs have been uncorrected and have been discarded.

If these errors are too high within a short period of time it will slow throughput... and could even lead to connection instability - See Out Of Cell Delineation.
Click to expand...

I think 2 losses of signal in an hour is quite bad. You shouldn't really have any if the line/modem were working properly.

As for age of modem. I use an old DG834GT which must be at least 5 years old.
 
Hi there cheers for that..

I did do line checks via phone and its the same as it was in test, which is just your normal quiet hissing which the line has always done.

With regard to that its not the first time I had to replace the homehub.

With regard to the test socket I through that by passes most of the houses wiring ? With that is so it must be external of the house... Or the hub... Or if im very unlucky both
 
The test socket does bypass all the internal wiring of your house. It's basically hooked directly to the external BT line. Everything from the test socket to the exchange is BT's responsilbity. Everything after the test socket is yours. Just watch that if it is your modem that BT don't charge you for the engineer visit.
 
Yeah im going to have to suck up the cost of a new hub and see.

What hub would you think is best for a adsl2 plus line like mine and I would like summer specs to my current
 
You could grab a DG834GT for around a tenner on the auction site, it's chipset is great for adsl2+. Something new would be a Billion at over 100.
 
Tealc said:
You could grab a DG834GT for around a tenner on the auction site, it's chipset is great for adsl2+. Something new would be a Billion at over 100.
Click to expand...

hmm, and I got a belkin ( i was was out at the time) its a N150.. I gotta wait for my line to seattle down but DB have dropped

ADSL
Type Interleave Path
Status SHOWTIME
Downstream Upstream
Data rate(Kbps) 286 446
Noise Margin 31 24
Output power(dBm) 12 11
Attenuation(dB) 16 8

still trying to get used to it a little, see if it has errors or it can record them.



latest speed test, still the same as you can see but like i said it needs a reset again..
 
It may actually retrain by itself but I'd probably contact BT to have them restart line training, or whatever they call it.

16 dB on attenuation is definitely in 20Mbit territory. This figure is actually the modem's estimate for line length. I'm not sure how it's measured and calculated but you will see this vary across different modems.
 
Hopefully it does, somehow a wire came out at the socket too, put it were it belongs but no sign of anything yet, look like a earth wire from the drop down to the main part of the socket
 
Not sure what that wire would be. There is no earth wire from the drop to the main part of the socket, unless you are talking about the ring wire, which should be removed.
 
Okay this is why I told my dad NOT to touch it but he did...

on the back plate ( the rear part of the socket) there is 3 terminals, there was a brown( or copper) coloured wire not attached to one of the terminals its quite hard to explain really. I dunno if its that loop wire you was talking about, since the house was rewired by bt a few years ago and such a wire would have been cut by them anyways or at least to my throughts

needless to say made little difference.
 
You must log in or register to reply here.
Back
Top Bottom