Posts Tagged ‘SNR’

The most common problem of ADSL connections, especially on long lines, is a low SNR margin value. The SNR margin (or Noise margin) is the relative strength of the DSL Signal to Noise ratio.

In case that you have upgraded your ADSL connection to a higher bandwidth (for example from 2 Mbps to 8 Mbps), you might be experiencing frequent line drops (disconnects). Especially during the night-hours there is a higher probability of having a lower SNR margin.

Depending on your ADSL router’s brand/model, you might be able to tweak the advanced connection settings.

Here I am going to describe how this can be achieved on a Netgear DG834PN router.  It could be working with similar Netgear models (Google is your friend!).

Please make sure that you follow the instructions carefully, and only change the settings that suit you.

The first step is to enable telnet connections to the router. Thus, start up your browser and paste the following URL:

The IP address should match your router’s address, so please change it accordingly.
The web interface is going to ask you for the administrator username/password.
Upon entering the correct details, you will see the message “Debug Enable!”.

Now that the telnet option is enabled, you need to connect to the router.
For example on a Windows command prompt just type “telnet”. On Mac/Linux just use the Terminal.

If the telnet connection is successfully established, type the following command to increase your SNR margin:

adslctl configure –snr 150

The 150 value is the percentage of the original SNR value.
For example if your original SNR value was 6 dB, than the 150 percentage would mean that you prefer an SNR value of 9 dB.

Increasing your SNR value, is decreasing your connection’s download bandwidth as well. However it’s better to have a lower bandwidth, than having a connection which constantly drops.

If you would like to restore the setting, than simply type:

adslctl configure –snr 100

… or just reboot your router. It has to be mentioned that the debug options are vanished after a router restart.

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