Ideal Parameters of DSL Line
1. SNR: SNR stands for Signal to Noise Ratio, Its value WILL HELP you to determine your line condition, to avoid disconnection. This SNR depends on your line condition ,its distance from your exchange,Jointing always decrease your SNR Margin.
5dB or below is very bad will result no sync or intermittent sync problems
6dB-11dB is fair, But result disconnections
12dB-22dB is good with no sync problems
23dB-28dB is excellent
29dB or above is outstanding
2. Line Attenuation
Line attenuation, It also depends upon your distance from exchange. Maximum signal loss recommendation is usually about 60dB. .but lower is always good .
and this will also help to measure how much max bandwidth u can get on your line .
on 60db line u will max get 1 Mbps ...
20dB and below is outstanding
20dB-30dB is excellent
30dB-40dB is very good
40dB-50dB is good, but result disconnections
50dB-60dB is poor and may experience sync problems
60dB or above is bad and will experience connectivity/speed issues