Uncorrectable errors, high latency, packet loss CM1150v/R7000

[Koz1614]

Hi all,

New to the netgear forum here..hoping someone can help me solve this mystery.

A few weeks ago, (possibly coincidentally) the same time everyone started working from home due to the pandamic, I have been having issues with my internet - especially gaming. I have spent a considerable amount of time troubleshooting with minimal success. Currently having latency spikes, packet loss and a high number of uncorrectable errors on the Netgear CM1150v. 

To date I have taken the following steps:

1. Fixed signal levels to modem - as you will see in the attached screenshots, my modem signal levels are all within spec now. With my 'old setup' the RF 'in cable' was connected to a splitter which then connected to a commscope CSAPDU9VP amp. I rewired to have my RF 'in cable' direct to the apmlifier and my signal levels were drastically improved. Downstream went from -9dBmV/SNR 36 to -3dBmV to 0dBMv and SNR 38-40. Upstream went from 50+ to mid 40's.
2. Replaced Arris TG862G with the Netgear CM1150V
3. Bypassed the R7000 and direct connected modem to xbox
4. Current firmware on all hardware
5. Tried different ethernet cables
6. Checked all coax connections, all have new fittings and no snags
7. Xfinity came out and checked the pole - signal level in road is good

Attaching photos of my modem status (note the modem was restarted last night - prior to the restart I had uncorrectables on nearly every channel) Also attaching a diagram of my network setup. If anyone has any thoughts I would greatly appreciate it. This has become incredibly frustrating.

[FURRYe38 · Accepted solution]

I never had the R7000, however I do have the R7800 and XR450 and the XR has a bit better range. The 450 and 500 are the same sans the 2.4Ghz connetion rate is slower on the 450 is all. The XR would have better speeds then the R7000 and will probably have better range. 

I have two EX7700s connected to my XR450 and that systems works very well for wireless coverage in a 5000Sq ft home. 

Glad the ISP fixed there side of the fence. Please mark your post thread as solved. 

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@Koz1614 wrote:

@plemans Connection is good..back to getting full speeds and even able to game online again. Latency is also good. As I said maybe im just looking for a level of perfection that cannot be achieved due to the nature of the ISP setup in my area. I dont think there is anything else I can do to improve things further. On a side note I did purchase an XR500 router. I was a little dissapointed with the 5ghz range compared to my R7000. Seems like the R7000 definitley had better 5ghz range especially when conecting to my EX7700. Do you know anything about the XR500 vs the R7000 ranges? Thanks again..you guys have truly been a big help !!

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[plemans]

You've got errors on channels 30-32. 

Problem with adding an amplifier. Yes it gets your signal to the good range. but if you're amplifying a bad signal it doesn't help. and can create issues on the upstream.

Try this. directly connect the modem to right where the coax enters the home. without the amplifier or any splitters. use the setup for a little while (to get some data moving), then take the same screen snips. lets see what it looks like then.

If that all looks good and the signal doesn't have errors and can tolerate a splitter then we move on from there.

the prefered way to run with cable tv and modem is a dual splitter when it enters the home. One leg goes directly to the modem and the other to amplifier/additional splitters needed. TV's and voip tend to tolerate erros/signal amplification better. 

this gives the best signal to the modem with the least amount of issues.  

[Koz1614]

@plemans Thank you! I will definitley try that. Currently the splitter I have is a 4 way due to the amount of outlets in the house. If I run a 2 way splitter off the main line, I will have to run one more splitter off the amp. 

So new setup would be:

Main line into 2 way splitter --> 1 line direct to modem, 1 line to 'in' amp

Amp 8 channels --> 1 line to additional 2 way splitter

Couple follow up questions:

1. Is the CM1150V a puma 6 chipset modem? ( I did research and it appears not)
2. Can the router/extender cause uncorrectable errors on the modem?

Thanks!!!

[FURRYe38]

The CM modems is not a Puma 6 based modem. Broadcom based. 

[Koz1614]

@plemans 

Hi, uploading my latest signal levels with new configuration.

New config has the main line to a two way splitter..one to modem, one to tv. Signal levels are down from where they were when connected the amplifier, but no uncorrectable errors as of yet (Modem has a little over an hour of uptime & signals are still in spec).

[plemans]

Looking good so far!

[Koz1614]

@plemans 

Well I have some uncorrectable errors again on channels 30,31, and 32 but signal levels still look pretty good. I brought the xbox and modem into the basement and direct connected to the main coax line into the house to remove all variables. The results were disappointing. The xbox connection test returned 16.75mbps down, 0.85mbps up, 41% packet loss and latency of 216ms. Normally I get about 225 down, 6 up, 0% packet loss and 60ms latency. 

At this point I believe its limited to a handful of possibilities:

1. Network card failure on the xbox (Highly unlikely)
2. Main RF coax cable that runs through lawn into house (Unlikely given that signal levels to modem are good)
3. Coax connections on box outside of house (Unlikely given that signal levels to modem are good)
4. Pole connections in road (Unlikely - Checked by Comcast last week)
5. Network/server overload on Comcast or Xbox end due to influx of people home with the pandemic (Likely)
6. An unknown comcast outage somewhere in the surrounding area (Likely)

I am leaning towards either 5 or 6 because prior to the pandemic I never had issues with online gaming. Any other thoughts? Thanks!!

[FURRYe38]

What happens if you connect the xbox directly to the CM modem and game there. See any issues that still continue? 

[Koz1614]

@FURRYe38 

Yes that was the test I did last night..Direct to modem. Modem was direct to coax in from road - no splitters involved. Eliminates nearly all variables. Not sure what to do at this point. 

[plemans]

have you tried eliminating the amplifier totally for testing? So no splitters but have the line come in and feed directly to the modem. 

maybe the amplifier/splitter setup is injecting/backfeeding interference into the line. 

Hook it up with no splits and see how it runs. If it still has issues its either: 

1. the modem

2. the line. 

It doesnt' leave much else if nothing else is on the coax line. Most places have a 30 days return window (with the covid stuff, some aren't accepting returns) so worst case, buy a new modem and if you still have the issue, then its the line and you can return the modem. 

[Koz1614]

Thanks @plemans 

Highly doubt it is the modem as the same issues were occuring with the Arris TG862G. I cant really connect directly to the main line without one split, since the main wire is in an awkward spot high on the wall. I came as close to connecting to the main line as possible last night. I connected main line to brand new two way split - 1st output running coax direct to modem (Also put a terminator cap on the 2nd split output to reduce any extra loss/noise). It has to be the line or some issue on xfinity side at this point. Thanks for all your help on this!

[FURRYe38]

IF this was happening with a different modem, then I would presume this issue is on the ISP side of the fence. Something they can look into. 

[Koz1614]

@FURRYe38 

I agree. Unfortunatley from my experience when you dont lease equiptment from comcast they will make a million excuses that the issue is not on them. Do you think that the uncorrectables can come from an outage somewhere in the surrounding area, not necessarily from the line under my lawn?

[FURRYe38]

Yep. I would ask for a tech to be sent out. Have them confirm what your seeing. Again, if two different modems are having the same problem, the ISP needs to look into this. 

[Koz1614]

@FURRYe38 @plemans 

One last question. Would the R7000 router/firmware have any effect on the number of uncorrectable errors on the modem status page or are the two unrelated?

[plemans]

Unrelated. The uncorrectables are between the cmts and modem. 

[Koz1614]

@plemans @FURRYe38 

Hi,

So the ISP came out to my area and performed some hardware/line upgrades. This was not specific to my home, rather it was an issue with my street and another. I know the work was complete because I have a dramatic improvement in my signal levels. The uncorrectable errors have also been reduced significantly. Prior to the upgrade I was seeing thousands and thousands of uncorrectables after a day or two of uptime on the modem. I am wondering if the few uncorrectable errors I am seeing now after a little over a day of uptime are considered 'normal'? Given the amount of time and effort I have put forth towards troubleshooting, hardware upgrades in home and testing its a bit disheartening to see any uncorrectables. So at this point are these uncorrectables normal or should there be a level of perfection? Attaching two screenshots. One is my modem immediatley after reboot, the second is with a little over a day of uptime. I have noticed the power levels on the downstream tends to fluctuate a bit (again not sure if this is normal).  Thanks!!

[plemans]

You expect a few correctable and even a few uncorrectables. When it starts causing signal/ping issues is when it becomes a problem.

How do speeds and latency look now?

[Koz1614]

@plemans Connection is good..back to getting full speeds and even able to game online again. Latency is also good. As I said maybe im just looking for a level of perfection that cannot be achieved due to the nature of the ISP setup in my area. I dont think there is anything else I can do to improve things further. On a side note I did purchase an XR500 router. I was a little dissapointed with the 5ghz range compared to my R7000. Seems like the R7000 definitley had better 5ghz range especially when conecting to my EX7700. Do you know anything about the XR500 vs the R7000 ranges? Thanks again..you guys have truly been a big help !!

[FURRYe38 · Accepted solution]

I never had the R7000, however I do have the R7800 and XR450 and the XR has a bit better range. The 450 and 500 are the same sans the 2.4Ghz connetion rate is slower on the 450 is all. The XR would have better speeds then the R7000 and will probably have better range. 

I have two EX7700s connected to my XR450 and that systems works very well for wireless coverage in a 5000Sq ft home. 

Glad the ISP fixed there side of the fence. Please mark your post thread as solved. 

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@Koz1614 wrote:

@plemans Connection is good..back to getting full speeds and even able to game online again. Latency is also good. As I said maybe im just looking for a level of perfection that cannot be achieved due to the nature of the ISP setup in my area. I dont think there is anything else I can do to improve things further. On a side note I did purchase an XR500 router. I was a little dissapointed with the 5ghz range compared to my R7000. Seems like the R7000 definitley had better 5ghz range especially when conecting to my EX7700. Do you know anything about the XR500 vs the R7000 ranges? Thanks again..you guys have truly been a big help !!

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