I seem to have a speed / reliability tradeoff with my Billion 7300G ADSL modem.
If I enable ADSL2+, the internet drops out many times a day.
If I enable only ADSL2, then I get slightly slower speeds (I’m quite far from the exchange), and dropouts happen every few days.
I then stumbled upon a “secret” menu:
http://{modem IP address}/iptv.asp
The “noise margin” drop down list gives you options of: Normal, IPTV, Maximum line rate, test lab 18, IPTV2, Others
Its currently set to “others”
I try a few settings, and these are the results:
Normal: 4093 kbps, noise margin (downstream): 7.2db
Maximum line rate: 4594 kbps, noise margin (downstream): 6.3db
test lab 18: 4775 kbps, noise margin (downstream): 6.1db
others: 4824 kbps, noise margin (downstream): 5.2db
This explains why many 5200G owners say its a very fast modem, but it works best if you are close to the exchange.
As the speed increases, the noise margin decreases and (I assume), the chances of a dropout increase due to changes in line characteristics.
So I decide to move from “others” to “maximum line rate”, and also change from ADSL2 to ADSL2+ (although I haven’t noticed any difference between ADSL2 and 2+).
After a few days, it looks like the modem is much more stable… no dropouts at all… its worth it for a slight drop in speed!