Yes!
The download margin (snr = signal to noise ratio) is a important value. It gives you a measure about the quality of signals.
Simply:
Everybody know a walkie talkie, as more u go far away from the other as more the quality goes bad, the snr drops down. The same is here.
The value on Annex A Modulation should not go fewer as around 7 (better is not under 10), AND SHOULD BE STABLE THERE :-O .
Annex A Modulation is used on the whole world only in German and Bosnia Herzogovina (Germans installed the i net there) NOT.
Annex A = analogue i net over phone
Annex B = digital i net over isdn
Back to snr:
As more bandwidth u use as fewer far u can use the i net cause the snr value goes with more bandwidth down, and they set me from 4 mbit (that was exhausted) too far way to high 6 mbit.
Hope i explaned it that all they read this can understand it
The Attenuation on download side should not get over the value 50 on Annex A, just as info.
Marwin