I decided to create a quick guide for those of you who want to understand your modem.
When you open your modem's manager, you'll likely see something like this:
| ADSL info: |
| Downstream | Upstream | |
| Current Rate(Kbps) | 16959 | 1150 |
| Max Rate(Kbps) | 20680 | 1216 |
| Noise Margin(dB) | 8.0 | 7.2 |
| Attenuation(dB) | 31.0 | 17.0 |
| Output Power(dBm) | 19.5 | 12.0 |
| Interleave Depth | 64 | 4 |
Current Rate (Kbps): This is the speed currently offered by your provider. If your internet is 10MB for download, then your Downstream should be 10000 (ten thousand). If your upload speed is 1.5MB, then the Upstream should be 1500 (fifteen hundred).
Max Rate (Kbps): This is the maximum speed for your system. This information is not as important; the maximum speed will be limited by your plan with the provider.
Noise Margin (dB): The noise on the line. The higher the number, the better. Thus, a Noise Margin of 10 is better than 7. This is very important information, as values below 9 (nine) will result in frequent disconnections and packet loss during transmission. It seems to be a consensus that 5db or less = bad, impossible sync, frequent drops; 8db-13db = regular - no modem sync issues; 14db-22db = very good; 23db-28db = excellent; 29db-35db = rare.
Attenuation (dB): Attenuation indicates the ease of transit between your modem and the central office (ARD) that transmits the internet to you. The higher this number, the worse it is. Providers may need to increase bandwidth for you to get the contracted speed when you are very far from the central office. In simpler terms, I see that 0 - 19dB = excellent, very close to the ARD (excellent cabling); 20-30dB = Very good; 30-40dB = good; 40-60dB = regular; 60-65dB = poor; 65dB or higher will have problems.
Output Power(dBm): Power used by the carrier to send the signal to the modem.
Interleave Depth: defines the number of bits (or bytes) in each data block. ADSL supports several interleaving levels, whose depth can vary from 0 (off) and from 1 to 64.
