[Sephiroth]

Welshchris is right in principle to suggest removing one attenuator although it might not help the upstream situation. Do check that the one remaining is a forward path attemuator (and indeed the one you removed) and confirm back. Is there a history that you can recall that might have led to the attenuators being put on?

I would expect the upstream power to fall slightly. If it doesn't, then there has to be a reason why the CMTS needs to demand such a power level to push through.

Looking at your stats, the UBR is a Cisco 10K not Motorola so I doubt it's a UBR fault. Congestion could in any case be a contributory factor in your user experience.

I should point out that the modem ought to be able to cope with the lowish power level. There are very few codeword errors and I don't think removing the attenuator will make much/any difference.

I'd still like to see the event log, please. It helps solidify the opinions.