Anyone know how the "DS attainable rate" shown when accessing the 2820 interface by telnet is determined. The screen shows the DS actual rate which matches that shown on the 2820s management screens via its IP address, yet in this case it also shows a DS attainable of 19492000 yet even on rebooting the connection remains about 5mb lower than that!

Is the DS attainable figure based on what the line could achieve at a specific (low) SNR? and perhaps the MSAN is set with a higher target snr?

This is on V3.3.1.2 (232201_A Annex A) - whereas on the previous firmware the "attainable" figure seemed to be what was then achieved at that point in time if the line was rebooted & it varied depending upon whether the weather/time of day was resulting in a different snr!

Get this firmware instead : Vigor2820 V3.3.1.2 AnnexA 211801.zip


Get it from here : ftp://ftp.draytek.com/Vigor2820/Firmware/V3.3.1.2/

Thanks groov - will get that. Do you know what the difference is meant to be between the 232201 & 211801 versions?, as I'd thought the one I was using was the UK version!
Thanks

Just a different ADSL firmware (as oppsosed to a router firmware)... Works better with certain brands of DSLAMs... i.e synch at higher rate

The 232201 seems like a very conservative firmware meant really for those with line problems.. but if you have none and want better perfs then the 211801 will give you that.

THere is no UK or foreign thing in these at all as the old 3.3.0 default firmware actually used the 211801 code.

Thanks - have tried that, but other than reporting a slightly lower snr ratio, the current DS speed & the attainable still show that strange 5mb difference!
Anyone else found this?

I think its due to the target SN if for example as in my case its 15dB but its actually connected at 17dB then actual rate is 1632000 where as attainable rate is shown as 179200 ie what I could get if everything went smoothly on a retrain.and the interference on the line remained steady. You are bound to get a difference as the level of interference changes throughout the day and night. So if at any time your actual SN ratio is above the target then theoretically you could get a higher speed.