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Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

duckware
Prodigy

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 Maintenance Ranging - No Response received - T3 time-out" errors.

I noticed other posts describing that this is a known Netgear FW bug/issue.  So what does it mean (what is the cause) and is there any workaround.  It is causing frequent Internet drops of several seconds, which kills video calls.

Seen at a location with really good download power/snr and upload power -- so it begs the question -- why is the Netgear FW messing up?

Model: CM1000|Ultra-High Speed Cable Modem—DOCSIS® 3.1 Ready
Message 1 of 19
FURRYe38
Guru

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

What is the brand and model of the host wifi router connected to the modem?
Please post a copy and paste of the modems connection status page.
Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://highspeed.tips/docsis-events/

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RAXE50 and R8500(v.158) Router Mode | Switches NG GS105/8 | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

Message 2 of 19
plemans
Guru

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

Got a screen snip of the cable connections page and event logs?  

One of the problems is that the cable connections page might look fine. But it only loads a snap shot of when its loaded. If something is causing issues with your line, your power levels might fluctuate. For example, I've seen a coax ran into someones house that rubbed against a tree. When ever the wind would blow to hard, it'd cause power levels to fluctuate at because of the worn area rubbing against the tree. thats just an example. So the cable connections page is the snap shot. the logs are what show longer term issues. LIke the "dynamic range window violation". Thats an indication that the power levels are going out of spec. 

 

So attaching your cable connections page and the logs help us to help you. 

Current setup: CAX80->Trendnet TEG-S380->GS716T-> RBK752->pi-hole
1.4gig download/50mbps upload
We’re members of the public helping out on our own time.
Message 3 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

Netgear R7800. Download 32 bonded channels power is great (4-6 dBmV), snr is great (40-41).  Upload bonded 5 channels with power great (44.0 dBmV).  Yep, ISP has been out a ton of times and they say there is nothing wrong on their end.  Of course there is a single splitter (without that there was only be a modem in the house with no cable boxes) feeding the modem and the rest of the house.  Cable is good/modern.

This problem only happens with Netgear CM1000 D3.1 modem.  Other modems don't have this issue.  I find it really interesting that I see this same issue at a totally different ISP as well.  This confirms the issue appears to be with the modem itself.

What is the MEANING of that message?

Message 4 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

Been monitoring power levels via a program every 60 seconds.  Rock steady.

Message 5 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

2021-10-16, 12:33:33 Warning (5) Dynamic Range Window violation
2021-10-16, 12:33:33 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-16, 12:33:33 Warning (5) Dynamic Range Window violation
2021-10-16, 12:33:33 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-16, 12:33:33 Warning (5) Dynamic Range Window violation
2021-10-16, 12:33:33 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-16, 12:33:33 Warning (5) Dynamic Range Window violation
2021-10-16, 12:33:33 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-16, 12:33:30 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-16, 11:14:17 Warning (5) Dynamic Range Window violation
2021-10-16, 11:14:17 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-16, 11:14:17 Warning (5) Dynamic Range Window violation
2021-10-16, 11:14:17 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-16, 11:14:17 Warning (5) Dynamic Range Window violation
2021-10-16, 11:14:17 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-14, 12:02:10 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-14, 11:52:11 Warning (5) Dynamic Range Window violation
2021-10-14, 11:52:11 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-14, 11:27:35 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-14, 11:27:33 Warning (5) Dynamic Range Window violation
2021-10-14, 11:27:33 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-14, 11:27:33 Warning (5) Dynamic Range Window violation
2021-10-14, 11:27:33 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;
2021-10-14, 11:27:33 Warning (5) Dynamic Range Window violation
2021-10-14, 11:27:33 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(MAC);CMTS-MAC=(MAC);CM-QOS=1.1;CM-VER=3.1;

Message 6 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

ChannelLock StatusModulationChannel IDFrequencyPower
1LockedATDMA135600000 Hz44.0 dBmV
2LockedATDMA229200000 Hz44.0 dBmV
3LockedATDMA322800000 Hz44.0 dBmV
4LockedATDMA416400000 Hz43.5 dBmV
5LockedATDMA539600000 Hz43.5 dBmV
6Not LockedUnknown00 Hz0.0 dBmV
7Not LockedUnknown00 Hz0.0 dBmV
8Not LockedUnknown00 Hz0.0 dBmV
Message 7 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

Comcast has been at this location many times.  Sadly, the contractors sometimes left things worse than when they arrived.  In my own research, I have learned more than I ever wanted to know about the impact of bad F-connectors and loose connectors.  I ended up doing a full 'audit' of every run, every connector, everywhere (even behind wall plates), etc.  I found some very bad workmanship on connectors and fixed.  I thought that had eliminated all problems, but something minor remains.  Still looking to understand the true meaning of "RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW".  I found a video by a couple of SCTE stating that this means the CMTS asked for the cable modem to transmit at too LOW a power level, but trying to verify.

Message 8 of 19
plemans
Guru

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

Its in regards to a ranging request and the power levels. You can get indepth details at the cable labs spec site but its basically between the cmts/modem and what its calling for power levels and what those levels should be at. 

https://www.cablelabs.com/specifications/search

 

do you have any errors in the downstream?

What does your docsis 3.1 ofdma channels look like? 

(for testing) if you just direct connect to where the coax enters the home (without the splitter), do you still get the errors? 

It definitely could be an issue with the modem. Especially if other modems don't have it. 

Did you try any of netgears other docsis 3.1 modems?

 

Current setup: CAX80->Trendnet TEG-S380->GS716T-> RBK752->pi-hole
1.4gig download/50mbps upload
We’re members of the public helping out on our own time.
Message 9 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

There are *zero* downstream "Correctable Codewords" and "Uncorrectable Codewords" -- until 'the event' happens.  Then maybe 100 or so codeword issues per channel.  And then no more codeword issues until the next event.

OFDMA download channel looks good.  power=4.9 snr=39.5.  No "Uncorrectable Codewords" until an event happens, then only a handful until the next event.

Yes, connected modem directly (via new 100' cable) to cable demarc location and still see the issue.

I see the same issue with two different CM1000V2 modems, at two different locations (one in FL and one in GA).  Yes, I guess the modem could be bad, but seeing this in two different locations and two different ISP's makes me think something else is going on.

The issue is not seen with other vendor's D3.0 modems, as that message seems specific to this NG 3.1 modem.  No, have not (yet) tried other D3.1 modems from Netgear.


Message 10 of 19
plemans
Guru

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

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. 

Current setup: CAX80->Trendnet TEG-S380->GS716T-> RBK752->pi-hole
1.4gig download/50mbps upload
We’re members of the public helping out on our own time.
Message 11 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

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).


Message 12 of 19
plemans
Guru

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

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. 

 

Current setup: CAX80->Trendnet TEG-S380->GS716T-> RBK752->pi-hole
1.4gig download/50mbps upload
We’re members of the public helping out on our own time.
Message 13 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

Thanks, all good suggestions.

 

Message 14 of 19
FURRYe38
Guru

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

"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)
    • 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
    • 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
    • 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
    • DOCSIS 3.0 allows bit more flexibility to shift Dynamic Range Window slightly for each ch if need be
  • DOCSIS 3.1 Dynamic Range Window (DRW)
    • 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
    • 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
    • DOCSIS 3.1 uses single Dynamic Range Window for all chs in TCC
    • Three types of Dynamic Range Window violations reported by BRCM DOCSIS 3.1 Cable Modem"

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RAXE50 and R8500(v.158) Router Mode | Switches NG GS105/8 | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

Message 15 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

Thanks a lot.  Yes, already found that (and watched entire video) and actually have been in contact with Brady Volpe.

Message 16 of 19
duckware
Prodigy

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

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

 

Message 17 of 19
Old_Soldier
Apprentice

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

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.

Message 18 of 19
FURRYe38
Guru

Re: What does "CCAP Commanded Power in Excess of 6 dB Below..." mean?

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.


 

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RAXE50 and R8500(v.158) Router Mode | Switches NG GS105/8 | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

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