I got O2 to re set my connection this morning as while I was away I had a firmware upgrade which resulted in my speed dropping from 2800 to 2300 and my snr downstream margin going up to 12.
As you can see by my stats they now show Maximum bandwidth as well as bandwidth.I don't think my line will manage to sustain 3500kbps,but we will see.I am gob smacked it has managed it at all
Uptime: 0 days, 11:30:07
DSL Type: G.992.5 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]: 833 / 4,538
Bandwidth (Up/Down) [kbps/kbps]: 863 / 3,572
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 0.00
Output Power (Up/Down) [dBm]: 12.0 / 17.5
Line Attenuation (Up/Down) [dB]: 40.0 / 66.5
SN Margin (Up/Down) [dB]: 5.5 / 6.0