said by Extide:That SNR of 27dB is WAYY low. You want to see about 35-37dB. The scale is logarithmic so 37dB is like 10x as much as 27dB.
You may be confusing that with the downstream SNR and not the upstream ?
Seeing as high as 35-37 dB on the uSNR as read at the CMTS would be quite rare, if not impossible.