[MUD_Wizard]

Originally Posted by chambohambo

Hi,

I have a intermittent fault which comes and goes. The problem is the upstream power level on both upstreams goes to 54dBmV, between Tuesday and Friday the power levels were very stable. What could be the cause of the fault I am getting?

Noise on the upstream, causing the modem to keep increasing upstream power levels as the CMTS cannot hear it. So the upstream power eventually maxes out at 54 dBmV. Which is the maximum power level for two 64 QAM upstreams.

You will likely see T3 and/or T4 timeouts (disconnections on the upstream) in your network log as well when this happens, though it is not guaranteed. The modem may stay online at that power level.


---------- Post added at 05:43 ---------- Previous post was at 05:37 ----------

Originally Posted by chambohambo

I get the exact same problem with the TiVo box

Naturally because both the hub and Tivo have Docsis modems inside that work the same way, with the same relative power limitations to the number of upstream channels and the modulation being used.

Originally Posted by chambohambo

which means on demand, YouTube, BBC iPlayer does not work, the picture and sound never breaks up when the fault occurs.

When the upstream power is maxed out you may be getting very low download speeds.