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Originally Posted by sav112
Downstream should be 331Mhz
Upstream 22-45mhz Frequency
power levels down -12 - 4
up 34 -56
SNR min 29 max 36 ( yours is 41) can effect conection quality.
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Upstream can be lower and higher than the frequency range you are suggesting, 45MHz as an upper limit makes no sense at all based on my knowledge of the kit (diplex filters, return path amps and lasers) that limits this band.
Power levels can go above +4dBmV with no issues. Telewest aim for +1dBmV. Modems should be ok between +15dBmV and -15dBmV, recommended between +10 and -10 though, +12 to -12 a good figure to allow some variation with the weather.
Upstream power of 55dBmV can be critically high depending on the modulations used in the upstream, it can infact be out of spec and cause connection drops. In some Telewest areas this will cause drops, in some it'll be about ok. Recommend this isn't any higher than 52dBmV for decent operation and some safety margin.
SNR there is no upper limit really, the higher the better. This is a measure of the average power of the wanted signal less the averaged power of the background unwanted noise - how can this be too high unless it's a ridiculous figure that's clearly a mis-reading?
29 is pushing it somewhat, really this needs to be upwards of 33dB if using (as the cable operators do virtually everywhere now where they are on DOCSIS) 256QAM downstreams.
NB using 'average(d)' for the sake of argument, it's actually not entirely accurate but I can't be bothered with explaining why it's not entirely accurate, it's good enough
EDIT: Bit of an old one to resurrect?