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What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?
"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW" means exactly what? Often seen with "Dynamic Range Window violation" and "Started Unicast Maint...
Finally, after a ton of tech visits, the ultimate problem causing this issue has been found: A bad cable from the top of the telephone pole (at the tap) running 15' to the base of the telephone pole (ground block). For full details (and more), visit: https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
Is it causing issues or just bothering you? (I'm slightly OCD on certain things and will spend far to much time trying to fix)
Looks like it happens within around an hour period each time it happens. Wonder if its coming from the CMTS.
I've got a pretty clean line as well and about once/twice a month I get a error. It doesn't cause any issues/slowdowns that I've noticed.
Using a CM2000 on xfinity.
When the issue happens, Internet drops for a bit. This used to happen a lot during the day, making video calls unworkable.
After inspecting all connectors everywhere and fixing problems, the issue now happens a lot less frequently.
Just trying to understand the true meaning of that error message in the log (and hopefully find the root cause).
It looks like its happening every couple days and for only a short period.
From reading your website and documenting what all you've done, you've hit most bases.
The only things I might try?
1. I've seen moisture in coax cables cause issues. Usually its more frequently then every other day. If there was rain in the line (you put they replaced) but then had issues with it being loose at the amp, might there still be moisture in the new drop?
2. grounds. make sure the splitters are properly grounded. I've seen grounds connected back to neutral on a seperate coax connection that bled interference back into the system. Boy was that a pain to figure out since that leg wasn't even used. I found it by disconnecting everything and slowing adding things back in until I found the leg that caused the issues. then it was troubleshooting that leg to see where the issue was.
3. Maybe its the firmware on the cm1000 that the isp uses. It wouldn't be unheard of. Maybe its submitting a call to the cmts in error and causing issues. Sadly, not much we can do to test that one.
Thanks, all good suggestions.
"DRW = Dynamic Range Window
there is a Dynamic Range Window to which CM can adjust power. For e.g. you cannot ask CM to to go from 30dBmV to 50dBmV suddenly. there is a window of 12dB which CM must follow.
basically, CMTS is asking CM to raise beyond DRW and CM is complaining he wont do it.
copied from below website:
https://volpefirm.com/dynamic-range-window-ofdma-troubleshooting/
- DOCSIS 3.0 Dynamic Range Window (DRW)
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During initial ranging on chs being added by TCC encodings, Cable Modem MUST cover entire Dynamic Range Window within 16 retries, leaving no power interval greater than 6 dB untried
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So for DOCSIS 3.0, by commanding power to mid of window it allows to go either 6 dB above or 6 dB below, which will cover whole 12 dB window
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DOCSIS 3.0 uses a per-ch Dynamic Range Window, whereas DOCSIS 3.1 uses a single Dynamic Range Window for all chs in TCC
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DOCSIS 3.0 allows bit more flexibility to shift Dynamic Range Window slightly for each ch if need be
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- DOCSIS 3.1 Dynamic Range Window (DRW)
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CMTS normally administers Dynamic Range Window of 12 dB [DOCSIS MULPIv3.1] which is sufficient to accommodate plant tilts of up to 10 dB from lower to upper edge of US band
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Since fidelity requirements are specified in flat freq conditions from top of Dynamic Range Window, it’s desirable to maintain Cable Modem Tx power levels as close to top of Dynamic Range Window as possible
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DOCSIS 3.1 uses single Dynamic Range Window for all chs in TCC
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Three types of Dynamic Range Window violations reported by BRCM DOCSIS 3.1 Cable Modem"
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- DOCSIS 3.0 Dynamic Range Window (DRW)
Thanks a lot. Yes, already found that (and watched entire video) and actually have been in contact with Brady Volpe.
Also, I have been trying to document everything (and what I learned) as I am going through the process of fixing the issues:
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
I've been getting these same warnings, in my modem's event log file. I'm on Xfinity extreme pro 900mbps, by the way. My modem isn't a Netgear model, but a Motorola MB8600. Power levels on the downstream channels range from +1.4dBmV to -2.8dBmV. I called Xfinity, yesterday, as I've been getting slow speeds for more than a week and got a US tech, rather than someone at their foreign call center. After explaining the problem and the fact that Xfinity's website shows a tech has been working 'in my area' for more than a week, the lady I was speaking with said there is something else definitely wrong with my line and a tech will be coming to look into things, on the 24th. Wish you luck with your problem.
Something you might ask Motorola about as well and see what there take is on that.
Old_Soldier wrote:
I've been getting these same warnings, in my modem's event log file. I'm on Xfinity extreme pro 900mbps, by the way. My modem isn't a Netgear model, but a Motorola MB8600. Power levels on the downstream channels range from +1.4dBmV to -2.8dBmV. I called Xfinity, yesterday, as I've been getting slow speeds for more than a week and got a US tech, rather than someone at their foreign call center. After explaining the problem and the fact that Xfinity's website shows a tech has been working 'in my area' for more than a week, the lady I was speaking with said there is something else definitely wrong with my line and a tech will be coming to look into things, on the 24th. Wish you luck with your problem.
