said by NormanS:
Margin (4.00 dB) is worse than marginal.
Different modems vary in how they determine this number and as a result also in how low it can be. Generally a SNR of 9dB or more is desirable for error free operation even in fast-track mode. Below 9dB modems generally are more stable in interleave mode because of its better error handling capability but when SNR goes below 6dB expect at least occasional disconnects. At 3dB and less the line becomes unusable (frequent loss of sync and retraining).
There is a direct relationship between SNR Margin, Attenuation and Sync/Data Rate. Attenuation tends to be fixed and is primarily determined by the loop distance between home and CO (however poor inside wiring can increase Attenuation!). Therefore the typical remedy for a SNR Margin that is too low is to decrease the Sync/Data Rate.
, you only posted one set of stats but it is unlikely that the stats are completely identical between testing at the NID test jack and inside the home. Try to leave the modem connected for some time (at least 15 minutes) before getting the stats (the modem may initially train at a higher speed and then drop down as a result of errors).--
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