Netgear DGN2200v4 Change SNR Target - Fix Line Stability [HOW TO]

hawker

Honorary Master
Joined
Sep 22, 2006
Messages
11,290
#1
My line stats are really bad and the line drops every couple of minutes. The issue has been going on for months and everytime a Telkom tech comes out its ok for a week or two and then it's back to normal. It was getting super frustrating to not have a stable internet connection and so I started looking at ways to achieve this (without Telkom's help). I realised that if I could somehow force my line to sync slower, I would be able to have a stable internet connection.

So, to do this you can force your router to target a higher SNR than what the default is. Before doing this I monitored my line stats and found that typically the Noise ratio would never really go above 8db and would be ok at +-6db for a little while and then it would just plummet down to 2 or 3 and sometimes even -1.0 db.

On some routers you have the ability to set the target SNR within the router software itself but with the Netgear DGN2200v4 you need to do a bit of work to get to the point where this is possible. Thank goodness the Netgear has a broadcom chipset otherwise I'd probably be out of luck.

So, how does it work? It works be changing the routers target SNR to a ratio of the originial. By telling the router to aim for a higher SNR I was able to achieve a stable connection without it dropping, however this does come at the expense of line speed.

The Netgear DGN2200v4 doesn't have an option to do this directly in the configuration pages and I wasn't keen to flash it with custom firmware. In order to change the target SNR one logs into the router using a telnet connection. Telnet isn't enabled by default on the DGN2200v4 so you'll have to download a little utility called telnetenable. Which I downloadeded from here: https://github.com/insanid/NetgearTelnetEnable

Enable telnet client in Windows if you haven't already and then you're good to go.

You start by running telenet enable from the command line - put it in an easily accessible place.

For example mine was:

Code:
C:\Users\Hawker\Desktop\telenetenable.exe
The app asks for a few input parameters [ip address of router] [router mac address] [router username] [router password]

*Note: the mac address should be entered without the colons.

So the command would look like:

Code:
C:\Users\Hawker\Desktop\telenetenable.exe 192.168.0.1 AABBCCDD00 admin password12345
If all goes well then you should get a message saying that telenet should be enabled on your router.

The next step is to configure the SNR target ratio.

Connect to your router over the telnet connection that you've now enabled:

Code:
C:\Users\Hawker\Desktop\telenet 192.168.0.1
A busybox terminal window should then be open. Now you can configure the SNR target by issuing:

Code:
adsl configure --snr N
Where "N" is the target ratio. 100 is the default. If you'd like the target SNR to be 1.5x the normal, then N would be 150. If you would like to push your line speed up even higher (possibly at the expense of stabilty you could enter an N value of less than 100). For mine to work I used N = 400. Now the noise margin is about 25db and the connection doesn't drop at all. I did use lower N values but the line would still drop after an hour or two.

I hope someone finds this helpful. If you have any other questions just ask.
 
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