Kitz Forum

Broadband Related => ADSL Issues => Topic started by: chris87 on November 03, 2006, 12:28:50 PM

Title: Poor Connection,Poor ISP, i can go on
Post by: chris87 on November 03, 2006, 12:28:50 PM
hello Everyone

i live in hull i am 19 years old study electronics and telecomms at college

However i have a serious problem with my internet connection and a odd one got broadband about 2 years ago started with 256K connection for the first 5 months had no problem what so ever didnt dissconnect once at all then all of a sudden it started to dissconnect 2-3 times a day so to try and solve this i re-formatted my computer and bought a new modem and filters but it just got worse and worse and it got to the point where i coudnt even connect from 9pm onwards no matter how many times i tried so the next day i rang up my ISP (karoo) after i told them what has been going on they just kept telling me it was spyware so i rang up again another day and they switched me to a lower port profile (no idea what that means) but it was fine after that.

months later we all got a free upgrade double speeds so i now had 500K connection strangely it ran better then the 256K connection  ??? but unfortunately all of a sudden again it just kept dissconecting so they switched me to a lower port profile and am still having problems i started to do a little bit of research and looked at my SNR and line attenuation an these are my results SNR margin downstream: varies from 12 to 25 and my line attenuation downstream is 61 so i asked to karoo how far i am from the exchange and my line is 4 miles away from the exchange which i heard is pretty far :(. and karoo told me my line cant even handle 1 meg

i just want fast speeds as i have 3 computers networked using Netgear router which is connected to master socket and we are very heavy users downloads,online gamers,msn etc 500K is just not good enough  :no: any help or advice people??? :P
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: kitz on November 04, 2006, 11:04:56 AM
Hi

If you are on a long line.. then there isnt really much you can do about the line length (attenuation)..  but there are several things you could perhaps try yourself to improve your SNR Margin, which will improve the stability of your line to keep the disconnects to a minimum.

The higher your SNR Margin, then the more likely you will be able to cope with the relatively higher speeds.

You may want to look at my low SNR (http://www.kitz.co.uk/adsl/lowSNR.htm) page for some tips.
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: Beano on November 07, 2006, 02:06:49 PM
I am also trying to get a better service from my ISP :lol:
On the website they keep offering 8Mbps but I can only get 1Mbs, despite paying for a 2Mb service.
The line speed tests indicate that the max line speed is 512kbps. :no:

I am using a Netgear DG834v3 router which is OK but I get an intermitent dropped lines the Downstream noise Margin goes to some fantastic number like 2147483639dbs.  Though occassionally the line remains working even whilst displaying this.

The normal stats from the router are as follows:

ADSL LinkDownstream  Upstream
Connection Speed1152kbps 288kbps
Line Attenuation52db 15.5db
Noise Margin15db19db

I live within 1.7crow flies miles of the Exchange This is 1.9miles driving distance (or 3km in new money)
Is it possible that MaxDSL could provide a better service.  After many months being batted between ISP, BTw, BT Openreach & Netgear. 

What do you suggest I do  :wall:
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: roseway on November 07, 2006, 03:50:03 PM
Hi Beano, and welcome to the forum.

Your normal stats are quite reasonable for what it obviously a longish line. You would get a faster connection with Max, but it would almost certainly be more liable to instability. The very large number you sometimes see for the noise margin is just a bit of bad programming by Netgear - it actually means that the noise margin has gone negative but the router doesn't know how to display negative numbers.

It looks as though you have a considerable problem with intermittent noise and you may be able to improve this by going to the link which Kitz provided above. It could also be a line fault, but you need to check out your own wiring and connections first.

Eric
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: Beano on November 07, 2006, 11:06:06 PM
Thanks Eric for your observations.

I'm sorry for not making it clear I have had many weeks of tests and work by BT Openreach and BTw.

This has resulted in a new route from the road box to my house, then a check of the line from the exchange which discovered a noisy power supply in a connection box on route.  This has improved the audible noise problem on the line.  In this process I have also changed the microfilters.

I do not have a master socket in the house but I have 4 normal sockets in different rooms.   1 with the Netgear and the other a BT Diverse 4016 base station 1 handset (2 others handsets are though the house)  the other 2 sockets are unused.

One area I have have considered is the DECT phones causing radio intererence when ringing etc.  The basestation is in the kitchen and the Netgear is upstairs I do have a handset in the office

Do you know of any research on this topic and what should be done to potential minimise problems.

I can't think of any other sources of noise.

Any comments would be appreciated.

Beano
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: roseway on November 08, 2006, 07:40:19 AM
I can't put my hand on any specific research at the moment, but I've certainly seen it reported many times that DECT phones can interfere with ADSL. Could you perhaps try unplugging the DECT base station temporarily and using an ordinary phone for a day or so to see if the problem still remains?

Eric
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: chris87 on November 14, 2006, 01:15:21 AM
strange things my line attenuation downstream was 61 now these are my results tonight

ADSL Link     Downstream     Upstream
Connection Speed    608 kbps    288 kbps
Line Attenuation    15.5 db    31.5 db
Noise Margin    15.4 db    16.0

line attenuation 15.5 wow lol
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: Beano on November 14, 2006, 02:01:34 PM
Hi Eric

I think I have made some progress on this problem. 

I do not have a master socket in the house but I have 4 normal sockets in different rooms.   1 with the Netgear and the other a BT Diverse 4016 base station 1 handset (2 others handsets are though the house)  the other 2 sockets are unused.

This has been changed by BT as a result of continuously notifying faulty line.  :wall: 
A BT engineer has change the system to include an NTE5 faceplate in the office.  The Netgear is plugged directly into the NTE5. The Dect phone is still attached through a microfilter on another phone point.

I took your advice and tried an old Vanguard phone in place of the DECT but the results were inconclusive however it did confirm that the RingWIRE is still connected.

The current router stats are as follows: :clap:
ADSL Link   Downstream    Upstream
Connection Speed   1152kbps    288kbps
Line Attenuation   53db    15.5db
Noise Margin   25db   23db

I have now much more margin so my line should now support a higher connection speed, whilst having a more stable service. However I suspect that the speed I am getting is programmed (or wired) into the DSLAM.  How do I get Pipex my ISP and/or BTw to change this top limit.   I am currently on 1Mb because when they upgraded everyone 18 months ago this was my maximum attainable speed.  :hmm:


Any comments would be appreciated.

Beano

Title: Re: Poor Connection,Poor ISP, i can go on
Post by: canon on November 14, 2006, 04:28:39 PM
Hi,
According to this: - http://212.23.23.177/calc.htm
A crude estimate of what your line is capable of is 6345kbps (kilo bits per second).
This figure is based largely on your current Signal to Noise ratio, and current line speed. The results you may obtain in practice are likely to vary, and thus this figure should only be used to estimate your lines capability.
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: roseway on November 14, 2006, 06:59:37 PM
I'm rather losing touch with which comments apply to which person's problem. :)

Beano, your figures look good, and if they are reasonably stable you would get a faster connection if you migrated to ADSL Max.

Chris87, your latest figures are not believable. I suggest that you re-boot your router.

Eric
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: canon on November 14, 2006, 10:32:00 PM
Sorry, I didn't make it clear  :-[ , my comment & result from http://212.23.23.177/calc.htm referred to Beano's stats.
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: Beano on November 14, 2006, 10:52:13 PM
Thanks Roseway and Canon for your views.

After 6 hours the downstream "Noise Margin" does fluctuate down to 15db.  :(

I'm not sure how the Noise margin relates to the Signal to Noise ratio in Canon's reply. ???

I am using a Netgear DG834v3 router Is it possible for me to change the download speed through the DSLAM SNR limited shown alseware on this site. :-\

Regards

Beano
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: canon on November 14, 2006, 10:57:27 PM
I've always used the Noise Margin figure from my DG834v2 in that estimator, I now know 'margin' and 'ratio' are different but it seemed to give the right answer for me with margin before I went to Max.
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: roseway on November 15, 2006, 07:22:28 AM
I'm not sure how the Noise margin relates to the Signal to Noise ratio in Canon's reply. ???
Signal-to-noise ratio is literally that - the signal level divided by the noise level, expressed in decibels. The noise margin is the difference between the actual measured SNR and a minimum acceptable SNR determined by the router manufacturer. So, for example, if the manufacturer determines that the minimum acceptable SNR is (say) 6dB, and the measured SNR is 10dB, then the noise margin is 4dB.

Eric
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: Beano on November 15, 2006, 08:43:38 AM
Thanks Eric

So that explains why the Netgear can operate down to very low Noise Margin.   
However as earlier posts indicate it has problems when the Noise Margin drops to 0.

Beano
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: mr_chris on November 15, 2006, 09:19:02 AM
I'd say that most if not all ADSL routers report the noise margin rather than the absolute SNR, even if they say "SNR" or similar.
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: chris87 on November 19, 2006, 05:13:11 PM
rebooted my router 3 times still 15.5db line attenuation downstream but other day i turned it on it went to 60 now its back down to 15.5  ???
Title: Re: Poor Connection,Poor ISP, i can go on
Post by: kitz on November 22, 2006, 09:26:05 AM
>>> rebooted my router 3 times still 15.5db line attenuation downstream but other

day i turned it on it went to 60 now its back down to 15.5 Attenuation shouldnt fluctuate - it should remain a more or less constant figure since its related to the length of your line. 
I suspect the 60dB was a one off bad reading/reporting figure.
 :-\