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Hard to say, especially not knowing what the weather is like in your area. Many satellite systems boost their power to try to prevent loss of signal due to rain fade. It would be more helpful to know the signal to noise ratio, if you are able to see those values.


Whoops, missed the cable part... (so that's why it's Dbmv and not Dbmw, lol... getting late) in that case, not sure about power levels and whether they are boosted in the presence of noise. I still say signal / noise is much more relevant than power, if you have access to those values.

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Tried finding DOCSIS specs, but couldn't find them. Found these from dslreports.com, and they're pretty reliable:

      Downstream power level (Receive): -15dbmV to +15dbmV

      A value of -15 or worse indicates a poor downstream signal path. A tech would aim for a value close to the optimal 0 dBmV, but a good cable modem should be capable of working within the broader range of -15 to +15 dBmV, provided the downstream Signal to Noise Ratio remains good enough.

      Upstream (Transmit): +8dbmV to +58dbmV.

      A value within the range +25 to +55 dBmV is within spec with 40's the most common. The lower this figure is, the better the upstream path to the UBR. If the cable modem is going offline, and the upstream signal strength is at +58dBmV, then a poor upstream path is probably the problem.

      Carrier/Noise Ratio: 30dB to 36dB .

      The downstream Signal to Noise Ratio must be 23.5 dB or higher, and should ideally be 30 dB or higher. The lower ratio the more noise and the poorer the performance. The Cable Modem will have to keep requesting retransmissions of packets with uncorrectable errors.

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Sparticus has Cox cable and I have Insightbb cable.

Edit:  I don't have the SNR page anymore.

I'm not sure what kind of cable I have, I'll check when it gets daylight but I think it is Quad something.  :icon_scratch:

I do have a satellite connection I know, I can see the dish.  :rolleyes:

I think that if your speeds are good use that as an indicator for later if it drops. Indicators and tests can show up differently from different sources so I always try to use the same one for evaluating my problem than evaluating the tests.  :-|

SNR from what I know would refer to a radio signal, maybe that's why the change.

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DOCSIS is affected by both CNR (carrier to noise ratio) and SNR. SNR is relative to anything that can lose signal to noise (in other words, any signal carried through any medium on ANY scale). For example, if you run any kind of cable (for example coaxial) next to a power line there would be signal noise caused by inductive interference (electricity going through a cable causes a magnetic field OUTSIDE the cable (think electro-magnet). Other things that would introduce noise in the signal are 90+ degree bends in coaxial cable, bad connectors (or improperly crimped), bad cable,  bad switches, long distances between the signal point of origin and the end point, etc, etc. For example, if you used a utility such as DocsDiag to diagnose your modem, the output would be something like this:

DocsDiag v020414 Copyright 2001-2 Robin Walker [email protected]

General Instrument SB3100 Cable Modem: Hardware version: 1; OS: VxWorks 5.3.1; Software version: 3.2.9p

Downstream channel ID                = 3

Downstream channel frequency        = 403000000 Hz

Downstream received signal power    = 0.0 dBmV (or not supported)

Upstream channel ID                  = 2

Upstream channel frequency          = 35984000 Hz

QoS max upstream bandwidth          = 128000 bps

QoS max downstream bandwidth        = 600000 bps

SigQu: Signal to Noise Ratio        = 33.8 dB

Cable modem status                  = Registration complete

Upstream transmit signal power      = 54.0 dBmV

Date and Time                        = 2002-04-14,21:18:12.00+00:00

Configuration filename              = mota4100-silver.cm

(see http://homepage.ntlworld.com/robin.d.h.walker/docsdiag/)

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Good info there, p0ltergeist.

Sparticus, it looks like you have plenty of headroom on both the forward and return.

Modems seems to run best between -5dBmV and +10dBmV at the receiver, and between about +35dBmV and +52dBmV for the transmit level.

This is from personal experience; so I would say that you have nothing to worry about.

I would like to see the downstream SNR ( or MER), but apparently the SA Webstar doesn't give up that info.

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Look up at reply #2 same as you. When I called Insight, they acted real dumb about it.

Maybe it's this brand of modem or something. Does this one work well for you? I had an arris phone modem and then I dropped Cox's phone service last week and they gave me this carppy Motorla which gave me about 7 down at peak times. Called them and they gave me this one, it works great.

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I have Comcast and the page works for me

Configuration Manager

Status Signal Addresses Configuration Logs Help

This page provides information about the current upstream and downstream signal status of your Cable Modem.

Downstream Value

Frequency 723000000 Hz Locked

Signal to Noise Ratio 36 dB

Power Level -9 dB

The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value

Channel ID 3

Frequency 21600000 Hz Ranged

Power Level 48 dBmV

Status | Signal | Addresses | Configuration | Logs | Help

How does this look,is everything right.

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