Recently I noticed, my 8Mb ADSL subscription, can only download with 600KB to 920KB per second using IDM, while it should be downloading with 1MB speed steady and not fluctuating like that! I also tested the 16Mb subscription, and the download speed went from 950KB to 1.2MB at best while it must have been around 2MB per second!
The speed test, reported 6.4Mb connection speed for my 8Mb, and 9.1 Mb for my 16Mb subscription. I myself think they have set a "Burst" mode or something like that causes this but I'm, not sure.
By the way here is the stats for my modem:
ADSL Firmware Version: FwVer:220.127.116.11_TC3087 HwVer:T14.F7_11.2 Line State: Showtime Modulation: ADSL2 PLUS Annex Mode: ANNEX_M
Downstream Upstream SNR Margin: 15.5 26.8 db Line Attenuation: 32.3 22.0 db Data Rate: 8192 508 kbps Max Rate: 17096 1836 kbps CRC: 10 0
Downstream Upstream SNR Margin: 6.1 32.6 db Line Attenuation: 31.6 21.5 db Data Rate: 16318 508 kbps Max Rate: 17904 2423 kbps CRC: 24 0
When I contacted the support, they said, your line noise is very high, and that is causing this, but I don't think so. Based on what I know, my Line Attenuation is not prefect but is fairly good, correct me if I'm wrong. And as far as I know, if the Line attenuation is high, I should be facing constant disconnection, and not that my speed decreases that much, am I right?
So what is the possible reason here? I don't know if SNR Margin affects the download speed or not. I know if too low, I'll face disconnection regularly, but I'm not sure if it affects the download speed! does it affect the download speed? for example a low SNR Margin causes a 16Mb to actually perform like a 9Mb? In that case, how should CRC look like?