Solved

Netgear DG834 high Noise Margin and loss of connection

Posted on 2006-07-18
36
6,168 Views
Last Modified: 2013-12-27
Hi,

I have a UK client who has a Netgear DG834G v1 router. This router has an Inbuilt ADSL modem. The problem my client is having is consistent dropping of the internet connection - There is nothing common to the time or situation of when the drop happens. It can be in the middle of a download or overnight when the connection is not being used - so it can happen at anytime.

The internet always drops over night and during the day will drop between 3-7 times. When the internet connection drops the ONLY way to resolve the problem is to reboot the router. However one thing i have noticed is the noise margin goes 'off the scale'. It will read normal between 4-7db while the internet connection is on. However when it drops the internet connection it reads something like 2349785676db which is not possible. This will resolve itself only once the ADSL\Router has been rebooted.

Can anything think why the noise margin does this or what could cause this and only resolve itself with a reboot ?

On the troubleshooting side I have upgraded the Routers firmware to the latest version, replaced the cables\filters.

Any information would be gratefully received !

Thanks

GISVPN


 
0
Comment
Question by:gisvpn
  • 15
  • 8
  • 4
  • +4
36 Comments
 
LVL 8

Expert Comment

by:hiteshgupta1
Comment Utility
What firmware version do you have?
can u specify theline attenuation (loss)
It should be in the "Router Status" page
You should be able to see the connection speed, line attenuation and noise margin over there

0
 
LVL 91

Accepted Solution

by:
nobus earned 168 total points
Comment Utility
i would have the adsl supplier check the signal quality, or the phone company.
Alternatively, you can test the modem on another site, to be sure it is not a problem with it.
0
 

Author Comment

by:gisvpn
Comment Utility
=================================
hiteshgupta1
=================================
Hey thanks for the post, the firmware on the router is V3.01.25 and the inbuilt ADSL modems firmware is 4.01.02.00.

The line attenuation is always the same = 28db download and only 6db for upload which i think are very good.

As I mentioned before, the noise margin goes to mental but everything else i have checked appear to be ok. Im just not sure what is causing the noise margin to go off the scale and only resolve itself when the router is rebooted.

=================================
nobus
=================================
Will try this, will try to plug another ADSL router in to the line and see if this resolves the problem.


Can anyone else think of anything this could be ?

Thanks

GISVPN
0
 
LVL 91

Expert Comment

by:nobus
Comment Utility
did you have the line quality checked?
0
 

Author Comment

by:gisvpn
Comment Utility
No I have not had this done, how would I ask, the telecoms company or my ISP or would either be able to do one ?
0
 
LVL 91

Expert Comment

by:nobus
Comment Utility
well ask the phone company which you pay . in our country it is a free service, and has helped already many.
0
 

Author Comment

by:gisvpn
Comment Utility
ok great thanks i'll check this out, do you know what sort of checks they can do and can i ask for anything specific?

I think in the UK they can do something called a WOOSH test ? But i am not that familiar with it. :)
0
 
LVL 91

Expert Comment

by:nobus
Comment Utility
in most cases, when you state your problem, they simply do a quality check of the line, to check it's status.
0
 

Author Comment

by:gisvpn
Comment Utility
ok thanks, will let you know how i get on
0
 
LVL 23

Expert Comment

by:bhanukir7
Comment Utility
hi there

the reason why the line is getting in the nights might be when the connection is idle because of which at the ISP end they try to disconnect any connections which are idle so that they can provide another use the dedicated bandwidth.

Secondly this might be due to Electro magnetic interference or a radio frequency interference(EMI/RFI). which might be causing the disconnection.

u can try observe if there is any radio broadcasting station or some kind of electrical switching which might be happenning.
It can also be due to power surge in the connection or a short circuit.

The ISP/Telecom people will check for the line quality if it has something to do with their line they will check that.
Its generally the telecom people who would do the line quality check.

but try to move the modem from the current location and put it in a different location i mean within the room and see. that should work if its a EMI/RFI issue

goodluck
bhanu
0
 

Author Comment

by:gisvpn
Comment Utility
H bhanu

I dont think this is because the internet connection is idle at night because it does not fit with the symptoms decribed. Also this line uses VOIP equipment and therefore this should keep the internet connection in use.

Not sure about the electronic\radio interference with the telephone line - is that really likely, never had problems with it before.

:) thanks

GISVPN
0
 
LVL 23

Expert Comment

by:bhanukir7
Comment Utility
hi there

if ur using a VOIP there is a likely possibility that when ever ur trying to make a call or recieve a call the dsl connection gets disconnected. i mean you can make a call or recieve a call but u tend to get disconnected when u take the call.

http://www.vonage-forum.com/ftopic4209.html

so try to speak to the voip provider and try to get that resolved.  This might be the reason for the high decible disturbance in the dsl connection.

goodluck
bhanu

0
 

Author Comment

by:gisvpn
Comment Utility
Hi bhanu,

No i dont think that this is the problem, as described in the original post diconnection happens at 'any' time, it does not matter what you are doing and the phones have been no problems for over a year.
0
 

Author Comment

by:gisvpn
Comment Utility
Still ongoing will give you an update soon :)
0
 
LVL 10

Assisted Solution

by:dragonjim
dragonjim earned 166 total points
Comment Utility
Unless the router / modem is wireless -- I would not suspect RFI problems (short of having the transmitter in the backyard).
Using VOIP myself, this should not be the problem, traffic is handled via packets (believe TCP/IP protocol).

Last time this happened to me (unmanaged Router only) -- the router was going bad.

Try hooking up another modem (or modem / router) to rule out a hardware issue. If another device works, I'd attribute it to hardware.
0
 

Author Comment

by:gisvpn
Comment Utility
Hi dragonjim, im starting to think that same ! Im also calling netgear to see if they will replace it :)
0
VMware Disaster Recovery and Data Protection

In this expert guide, you’ll learn about the components of a Modern Data Center. You will use cases for the value-added capabilities of Veeam®, including combining backup and replication for VMware disaster recovery and using replication for data center migration.

 

Expert Comment

by:bwff
Comment Utility
gisvpn
I have exactly the same problem with the DG834G v1 with the latest firmware so your are not alone on this issue.
I've contacted my ISP who asked the usual questions, adsl filter, latest firmware, near any power sources etc..etc
The ISP then contacted BT to do a woosh test and that checked out okay. Made them do it twice.
I've also replaced my cable and adsl filter.
The strangest thing is that I've just changed my DSL service from a 2MByte DSL to an 8Mbyte MaxDSL service, it is still with the same ISP, then this issue started happening.
Due you know what ISP service your client is using

0
 

Author Comment

by:gisvpn
Comment Utility
Hi Bwff,

thanks for the post.... It sounds like we have the same problems and hav tried the same things.

Mine is still donig it, does your Noise Margin also go to a high number when it drops the internet connection ?

I called netgear and explained everything and they agreed to replace it !! good news as i didn't think it was still in warranty, but it must be !

I am going to use a BT Home hub while the other one is being exchanged and see if the internet connection drops with that and we will see what happens when I get another back from Netgear.

Also strange you should mention the line upgrade, I think this line was upgraded from 2 - 8mb. Who is your provider ?
0
 

Expert Comment

by:bwff
Comment Utility
Provider is Zen Internet
noise Margin is just a bit lower than your clients around 210000000db.
0
 

Author Comment

by:gisvpn
Comment Utility
humm this is through UKOnline... I'll let you know how i get on with the replacement, will you call netgear for a replacement ?
0
 

Expert Comment

by:bwff
Comment Utility
The company I work for will buy me one as I do call out, although I have managed to borrow another netgear router so I should be able to test it tomorrow night.
I'll let you know how I get on.
0
 

Author Comment

by:gisvpn
Comment Utility
yeah that would be good, thank you. I'll let you know how I get on with the BT home hub and the replacement Netgear.

GISVPN
0
 

Expert Comment

by:bwff
Comment Utility
Last night I rolled back to V2.10.22 firmware level and it seems to have stabilised it's been up for 14hrs, will keep it running to see if I get the same issues.
Did you try it with this firmware level.
0
 

Author Comment

by:gisvpn
Comment Utility
Yes the router was previously on 2.10.22 when it started having problems and we upgraded to 3 just as standard support procedure, however a re-apply of 2.10.22 may help - let me know how you get on ! :)

GISVPN
0
 

Expert Comment

by:bwff
Comment Utility
one of the recommendations that BT gave me was to reset my router and re-load my config back in, this was to QUOTE "clear out any potential clutter in the router".
I've only done this under V3.01.25 firmware level, but it looks as if you've done this already.
0
 

Expert Comment

by:bwff
Comment Utility
I've found out why the noise margins is so high, it means that there is a negative value for signal to noise ratio.
Apparently netgear folks didn't understand the difference between signed and unsigned 32bit numbers for this resulting in the huge values that we are both seeing.
0
 

Author Comment

by:gisvpn
Comment Utility
humm interesting..

How can it pick up a negative number for STN ?

Im not too sure about signed and unsigned 32bit numbers - could you please explain ? :)

Thanks

GISVPN
0
 

Assisted Solution

by:bwff
bwff earned 166 total points
Comment Utility
signed and unsigned numbers explained better than I would.
http://webster.cs.ucr.edu/AoA/Windows/HTML/DataRepresentationa5.html

I've had a very pleasant chap explain to me what is happening on my router.
When the signal to Noise ration hits 0 or less(negative)decibels it causes you to lose sync briefly where most modems/routers can recover from it, in our case, the dg834g isn't.
To prove this when the connection is lost go into the netgear gui and go to router status, click connection status, then click connect you will be able to reconnect. I've actually done this when I was running v3.01.25, but I kept looking at the Noise Margins and rebooted the router as I found it off-putting.

So Ignore the noise margin results as this is a bug within the netgear firmware and will only be reset when you reboot the router.

In addition to this my netgear router has been up for over 24hrs on the 2.10.22 firmware level, the first since I've moved to the 8MByte maxdsl service. However I don't get great download speeds.

I'm now considering replacing my router as I don't think the DG834 v1 netgear router is up to job for MaxDSL connections.  
0
 

Author Comment

by:gisvpn
Comment Utility
yeah i think you are right about the V1 not being up to it. I have plenty of clients who use the v3 and they have no problems....

Will see if netgear replace it with another v1 !

Thanks for the explaination for signed and unsigned ! ;)

GISVPN
0
 

Expert Comment

by:bwff
Comment Utility
bit of an updated on this
No problems with v2.10.22, it ran sweet for 3 days.
Upgraded it to v3.01.25 and it's been running sweet for 3 days, hasn't crashed once.
However the web gui into netgear config does some strange things and takes me a few attempts to connect into it.
I've got a new router a DG834GT, company got it for me, so I'm going to plug it in as the download speeds still ain't that great.
I do a bit of online gaming and it's great not to lose my connection when I've got a great score.
0
 

Author Comment

by:gisvpn
Comment Utility
Hi,

great stuff let me know how you get on with the DG834GT....

Im still waiting for the new replacement router from Netgear and will be putting in the home hub this weekend ;)
0
 

Expert Comment

by:Cecil_Ward
Comment Utility
Much in this discussion hangs on questions of router firmware.

The Netgeear DG834v1 being discussed had firmware that exhibited a bug in the display of signal-to-noise ration figures that went down to 0dB and then briefly went negative. The bug was fixed in later firmware releases.

Later firmware releases for the Netgear DG834 v1/v2/v3 - these devices being TI AR7 chipset-based - included improved DSL firmware that reportedly fixed the stability problems very effectively. Only some users ever experienced these problems, others found these devices to be extremely stable and fast on very poor lines. I am not aware whether all these improvements were available to DG834v1 users, but this would appear to be a safe assumption.

These comments are based on long term testing of DG834v3 units, with lesser experience of a few v2 and v1.

The Netgear DG834v4 is not included in these comments as it is based on a completely different chipset (Broadcom, not TI).

See release notes on the Netgear website. [Unfortunately release notes are poor, and some critical fixes are most definitely present but have not been written up.]
0
 

Expert Comment

by:Cecil_Ward
Comment Utility
The original 'experts' who commented on my case gave IMO defective advice that was very incomplete.

A great number of ADSL problems are related to poor wiring in the premises, bad ADSL modems and  firmware defects, bad microfilters and RFI and other electrical noise,

The user should have been told to update firmware, have been given recommendations on alternative router models, microfilter models and the importance of extension wiring and correct (short) ADSL signal cables, and the importance of taking steps to ensure a low-noise environment (many many practical steps available in this category).
0

Featured Post

What Security Threats Are You Missing?

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

Join & Write a Comment

Suggested Solutions

Hi there, This article summarizes what you need if you are going to set up your home or small business Network Attached Storage (NAS) to be accessible from the internet. Of course there are configuration differences based on your NAS or router ma…
In this seventh video of the Xpdf series, we discuss and demonstrate the PDFfonts utility, which lists all the fonts used in a PDF file. It does this via a command line interface, making it suitable for use in programs, scripts, batch files — any pl…
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…

763 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now