CM1000 Xfinity issues

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vkdeltawrote:

do you have lot of attenuators or splitters at home?

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The main coax line comes into the garage where, via a splitter, it feeds all the coax outlets in the house.  Each coax outlet has a unique line from the main splitter in the garage.  Regarding the outlet that the modem is plugged into, I had two, two-way splitters on it: one with an output to the modem and an output to the input of the second two-way splitter, and the second two-way splitter had one line to a cable box and one line to a bonded MoCA 2.0 adapter for our MoCA network.  We actually got rid of the cable box, so I removed that splitter and now the coax outlet only has one, two-way splitter: one output feeds the modem and one output feeds the MoCA adapter.  I'm not sure what you mean by attenuators, but we do have two POE filters on our coax, one at the main line into the garage to be sure our MoCA network doesn't leave the house, and a second attached directly to the modem because I was advised that modems don't appreciate being bombarded by the electronic traffic the MoCA network generates.  Below are links to pics of updated screenshots of the cable connection.  Power issues seem to have gotten worse!

https://imgur.com/F2rfTWe

https://imgur.com/Im80kK3

https://imgur.com/Akpkz8A

NBCGLX

power levels are still bad (though I dont see uncorrectables and that may be because you did not the run traffic for a while).

what is the your power level at the coax entry point in your home? 

Have you tried using active return path? (these are tricky as some of them distort signal and even make it worse).

Have you tried asking to remove attenuation outside your house so you can boost your signal level? (typically at the node at the street).

Power levels are "bad" => What are examples of good and bad power levels?  Please writeup some docs on how to self-diagnose this stuff, would be useful.  What are bad levels of errors?  What do the specific error messages mean in the log, etc..

Dahbehr

Please attach the full power table + event logs. 

your modem shows it is not even bonded D3.0 QAM channels. 

DHCPv6 server from comcast is not responding (have seen this happening when there was an outage in an area). 

how long have you seen this? or it just started happening.

where are you located? 

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vkdeltawrote:

NBCGLX

 

power levels are still bad (though I dont see uncorrectables and that may be because you did not the run traffic for a while).

 

what is the your power level at the coax entry point in your home? 

Have you tried using active return path? (these are tricky as some of them distort signal and even make it worse).

Have you tried asking to remove attenuation outside your house so you can boost your signal level? (typically at the node at the street).

 

 

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How would I know the power level at the entry point?

What is active return path?

No, haven't asked Comcast to remove attenuation outside our home to boost our signal level. Remember, they're convinced the service is just fine and it's the modem that's the problem.

I ran into the same problem and spent 4 hours with both Netgear and comcast rep.  It doesnt go anywhere as comcast said it's modem and netgear said comcast with cable line with noises/traffic.  reset model, power up/down....  not sure I want to go with diffent brand of modem

Yeah, Comcast is a horrible company and they're always looking to place blame elsewhere. Not my cables. Not my service. It's YOUR equipment that's the problem! So tired of this BS. I feel like the only way this will be solved will be to fork out the money to get Comcast's stupid modem/gateway or whatever they call it and prove to them that I still can't get anything close to the gigabit speeds I'm paying for. It's infuriating.

Your upstream power levels are WAY too high.  Look at the second image you posted. Look at the three upstream channels under power.  All three are around 59 and they should be about 30-35.  This is a COMCAST issue.  I just called them they other day and I told them what to look at and they found that it was not just my house but 7 other houses with the issue.  You need to tell them what to do.  If they send someone to the house, show them those three channels.  Ask that they look on the tap to see if it's the same out at the street.  If it is, it's their problem.  If it isn't, then it's a cabling issue.  My internet drops out like 4 times a day.  They replaced every cable from the tap to the modem including trenching a new cable under my yard.  It is not the NetGear modem.  It's a wayward amp or connection somewhere in the system.  You have to be persistent with them.  Don't give up.  I actually ended up getting a call from Corporate because I am now labeled a "chronic" customer.

Post your modem connection page.  Look at the downstream power levels.  Are there any channels with a very high number of uncorrectable codewords?  By high I mean millions or billions.  If you can post that full page here, the community can better assist.  BTW, these issues seem to be almost always COMCAST issues not NetGear issues, but you have to tell them specifically what is wrong.  It will usually mean a trip to the house by a tech.  I work at home so it's no big deal but for others, that can be a pain in the butt.

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jgnoonan wrote:

Post your modem connection page.  Look at the downstream power levels.  Are there any channels with a very high number of uncorrectable codewords?  By high I mean millions or billions.  If you can post that full page here, the community can better assist.  BTW, these issues seem to be almost always COMCAST issues not NetGear issues, but you have to tell them specifically what is wrong.  It will usually mean a trip to the house by a tech.  I work at home so it's no big deal but for others, that can be a pain in the butt.

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I have mine posted above, but here they are again:

https://imgur.com/F2rfTWe

https://imgur.com/Im80kK3

https://imgur.com/Akpkz8A

I don't know to get them to show inline with the post.

CM1000 statusIs this right after a boot and a reset of the modem? Because mine looks nothing like that.

Hello NBCGLX

You levels seem to be off a little low on the downstream and high on the upstream do you have any splitter connected 

Mrgoodall You look to have some uncorrectables are you seeing any timeouts in your logs.

DarrenM

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DarrenM wrote:

Hello NBCGLX

 

You levels seem to be off a little low on the downstream and high on the upstream do you have any splitter connected 

 

Mrgoodall You look to have some uncorrectables are you seeing any timeouts in your logs.

 

 

DarrenM

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One splitter where the main line comes into the garage that feeds 4 coax outlets in the house. One of the outlets feeds another splitter, which feeds the modem and a MoCA 2.0 bonded adapter for our MoCA network.

You may want a ISP tech to come out and check the levels on your lines.

DarrenM

they dispatched a tech, he looked and saw it was a indeed a line quality issue, had to scheudle a line tech to complete maintence. based solely on signal quality, he showed me his readings, they showed "DOCSIS Failure". 7-10 business days until line tech completes work. 

I wonder why these cable modems are not smart enough to detect line signal issues and let the user know?  Seems like an easy to add feature that would be useful for customer.