Router Stats

[freedom123]

Hi Pada and Experts,
Please see my D-link router stats below. According to the line attenuation thread, I should not be able to receive ADSL. I run fine on 4 meg and speedtest shows 3.6 now. Please comment.
Downstream Upstream
Line Coding( Trellis) : On On
SNR Margin ( dB) : 109 120
Attenuation ( dB) : 535 315
Output Power ( dBm) : 190 119
Attainable Rate ( Kbps) : 5152 824
Rate ( Kbps) : 4096 512
Zak

 

[Satguy]

My DLink also gives me similar line stats, I think there is a decimal point missing -

Should read:

SNR Margin ( dB) : 10.9 12.0
Attenuation ( dB) : 53.5 31.5

Gary

 

[Pada]

Satguy is correct.
The modem is actually showing the stats in 0.1dB units, implying that you should divide those values (SNR, Attenuation & Output Power) by 10.

Your SNR margins are quite impressive for a 4Mbps connection where you have such a high line attenuation!
If you know that your attenuation values were much lower previously, you might be able to get Telkom to get your ADSL line in the state it was previously. Attenuation is the amount if signal loss, primarily due to the distance from your home to the DSLAM/Exchange. The lower this value, the better!

3.6Mbps on a speedtest is the fastest you'll ever get on a 4Mbps ADSL connection, due to the transport (TCP/IP) overhead of about 12%

 

[Roman4604]

due to the transport (TCP/IP) overhead of about 12%

IP & TCP only account for about 1.5% overhead. The rest is due to the ATM cell technology ADSL was designed upon from the start. Every cell has a 5 byte header for 48 bytes of payload.

 

[Pada]

Thanks Roman4604 for correcting me

I now found a more correct (but not very precise) answer: "9.4% of ATM, 1.65% of TCP, 1.3% of IP, and .53% of PPPoE of overhead giving a total of 12.9%"

I still wonder how some people managed to get 1Mbps on their speedtests.net tests when their lines sync at 1Mbps! ADSL2+ still relies on this ATM tech!?

 

[Roman4604]

I still wonder how some people managed to get 1Mbps on their speedtests.net tests when their lines sync at 1Mbps!

Physically can't, probably just software misreading (e.g. browser,flash etc.)

ADSL2+ still relies on this ATM tech!?

Yes