@insane79
Get line checked.... or relay the wire from
router to ground floor junction box..... mostly that is the culprit....
My Line Atte downstream is higher than yours at 27dB...... but still I have 24dB SNR downstream..... so u can improve your SNR by fixing your line..... I hope those stats were on
ADSL2+ Annex M.....
At 26dB Line atte....... u should be fine with 8Mbps if you can improve your SNR...... but as far as port problems...... that depends on the port your on....