Is My Router Snr Margin Okay?

[Blackcoda786]

is my snr margin okay? Is it too low? I am not sure about this. i am using true internet and have 4mbps download.

[Blackcoda786]

SNR Margin 18.7 /25.0 dB

Line Attenuation 28.1 /17.5 dB

Errored Seconds 1 0

Loss of Signal 0 0

Loss of Frame 0 0

CRC Errors 1 0

Data Rate 4096 /512 kbps

Latency INTERLEAVED /INTERLEAVED

[monty]

Your snr ratio is just fine considered the speed (4096kbps) it is connected at!

If your snr is not high enough, your router will shift down in speed until the snr is high enough to sustain an errorless connection!

There is not much margin (12dB is considered a minimum) but this perfectly normal at that speed, especially considering the quality of the cabling in Thailand

The maximum speed for adsl is 8mbps, but for your router being able to connect at that speed you virtually have to live on top of the telephone exchange

Anyway, this is all theoretical since the international bandwidth is not sufficient enough to give you this speed.

The bottleneck is only at your Isp connection to the outside world (courtesy of the Communications Authority of Thailand) and ot with your adsl link!

[Blackcoda786]

Thanks for replying monty

I was wondering does high or low snr margins matter? How does it degrade/increase speed? Sorry for too many questions, im pretty much curious.

[monty]

There's two parameters important on an ADSL connection.

The first is the line attenuation, expressed in dB. The higher this number, the more signal loss you have on the line. On a normally functioning line (no bad connections etc...) this is purely a result of the length of the phone line between your location and the telephone exchange.

The longer the line, the more signal loss, the higher the dB number.

Low numbers are good, high numbers are bad.

Most ADSL suppliers will only hook you up if your line attenuation is less then 60dB.

The second is the SNR (signal to noise ratio).

Your phoneline picks up noise on the way to your house. This noise can come from other ADSL lines, high tension transformers, powerlines etc...

You can see from the way the lines are strung on the poles in Thailand, that your average phoneline will pick up quite some noise! The clearer the real ADSL signal is compared to the noise, the higher the SNR. (high is good)

An errorless connection needs nomally 12dB or more.

In simple language, if there is to much noise on the line, the router will not hear the difference between the data (ADSL signal) and the noise.

The higher the connection speed, the lower the SNR gets, because high speed data is more difficult to differentiate from noise then low speed data.

Thats why, when the SNR at the speed you subscribed is not high enough, your modem will try a slower speed as this will increase the SNR.

Your ADSL router/modem can compensate for these parameters within certain limits. If the line attenuation is to high, it will automatically increase transmit power.

If the SNR is to low, the router will shift down to a lower speed, until a sufficient high SNR can be obtained.