OK i looked here
http://www.cableforum.co.uk/board/sh...ad.php?t=26006 about cable modem signal levels and i copy paste mine:
Downstream Receive Power Level : -4.2 dBmV
Downstream SNR : 34.6 dB
Upstream transmit Power Level : 50.0 dBmV
According to this guide the only "strange" value is
Downstream Receive Power Level : -4.2 dBmV which should be +- 3dBmV.