My attenuation at this moment on Netgear DGND3700v2 is 23.5/15.5 dB. At this moment I have SNR margin ~4 dB and the same synchronization since 4 months. But upstream SNR margin is consistently deteriorating. On the first month I have ~6 dB, now I have ~2.5 dB. On the first month almost 0 CRC errors on weeks, now I have about 60 000 CRC errors per 12 hours.

Best regards

konrado5