Reply
vkdelta
NETGEAR Employee

Re: CM1000 Xfinity issues

try uploading to imgur.com and posting links here.

Message 51 of 79
NBCGLX
Guide

Re: CM1000 Xfinity issues

Model: CM1000|DOCSIS® 3.1
Message 52 of 79
martyr444
Apprentice

Re: CM1000 Xfinity issues

@NBCGLXYour upstream power is way to high and your downstream power could be closer to zero.

Message 53 of 79
NBCGLX
Guide

Re: CM1000 Xfinity issues


@martyr444wrote:

@NBCGLXYour upstream power is way to high and your downstream power could be closer to zero.


Thanks. How does one fix that?

Model: CM1000|DOCSIS® 3.1
Message 54 of 79
martyr444
Apprentice

Re: CM1000 Xfinity issues

@NBCGLXXfinity Comcast needs to resolve this. If the tech cannot fix it, they may need to get maintenance to get your levels corrected. 

Message 55 of 79
vkdelta
NETGEAR Employee

Re: CM1000 Xfinity issues

do you have lot of attenuators or splitters at home?

Message 56 of 79
NBCGLX
Guide

Re: CM1000 Xfinity issues


@vkdeltawrote:

do you have lot of attenuators or splitters at home?


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

Model: CM1000|DOCSIS® 3.1
Message 57 of 79
vkdelta
NETGEAR Employee

Re: CM1000 Xfinity issues

@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).

 

 

Message 58 of 79
MattN
Tutor

Re: CM1000 Xfinity issues

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..

Model: CM1000|DOCSIS® 3.1
Message 59 of 79
Dahbehr
Aspirant

Re: CM1000 Xfinity issues

Can anyone explain this? Comcast came out today and hooked up their XB6 modem and poof worked fine. I was watching YouTube last night and the internet just cut out immediately and haven’t been able to fix it. The modem downstream and upstream lights both turn solid then the internet blinks. It seems to time out then repeat this process over and over. Comcast says the modem is bad. The modem is less than two weeks old. This is very frustrating because nobody seems to know what’s going on and I don’t want to pay Comcast $10 a month. Firmware is update also. When I go into the log files they all just say dhcp failed or synchronization failure.

If anyone has an idea what’s happening that would be great.

Message 60 of 79
vkdelta
NETGEAR Employee

Re: CM1000 Xfinity issues

@Dahbehr

 

Please attach the full power table + event logs. 

 

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

Message 61 of 79
Dahbehr
Aspirant

Re: CM1000 Xfinity issues

Correct. Comcast can’t even see the modem is online so they can’t even troubleshoot it. It was working fine until yesterday afternoon when it abruptly stopped.
Message 62 of 79
vkdelta
NETGEAR Employee

Re: CM1000 Xfinity issues

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? 

Message 63 of 79
Dahbehr
Aspirant

Re: CM1000 Xfinity issues

It just started yesterday around 2pm cst. Located in St. Paul, Minnesota. They hooked up their own modem and that works fine. I just don’t want to get stuck paying them $10/ month to rent a modem. So it doesn’t appear to be an outage issue.
Message 64 of 79
NBCGLX
Guide

Re: CM1000 Xfinity issues


@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).

 

 


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.

Model: CM1000|DOCSIS® 3.1
Message 65 of 79
taichi
Tutor

Re: CM1000 Xfinity issues

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

 

2018-04-20, 22:50:18Notice (6)CM-STATUS message sent. Event Type Code: 3; Chan ID: N/A; DSID: ; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 22:50:18Warning (5)Unicast DSID PSN startup error
2018-04-20, 22:47:41Warning (5)REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedNotice (6)Honoring MDD; IP provisioning mode = IPv6
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 22:41:33Critical (3)Resetting the cable modem due to docsDevResetNow
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 18:31:17Critical (3)Resetting the cable modem due to docsDevResetNow
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:55:24Critical (3)Resetting the cable modem due to docsDevResetNow
2018-04-20, 08:45:06Critical (3)No Ranging Response received - T3 time-out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:34:41Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:34:36Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:34:17Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:34:16Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:33:57Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:33:56Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:33:37Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:33:36Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:32:58Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:32:52Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 08:32:49Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:31:38Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:31:33Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:31:13Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:31:13Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:30:53Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:30:53Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:30:33Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:30:33Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
2018-04-20, 07:29:59Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:39:56:9c:67:41;CMTS-MAC=00:9e:1e:58:d4:ef;CM-QOS=1.1;CM-VER=3.1;
Model: CM1000|DOCSIS® 3.1
Message 66 of 79
NBCGLX
Guide

Re: CM1000 Xfinity issues

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.

Model: CM1000|DOCSIS® 3.1
Message 67 of 79
jgnoonan
Star

Re: CM1000 Xfinity issues

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.

Model: CM1000|DOCSIS® 3.1
Message 68 of 79
jgnoonan
Star

Re: CM1000 Xfinity issues

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.

Message 69 of 79
NBCGLX
Guide

Re: CM1000 Xfinity issues


@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.


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.

Model: CM1000|DOCSIS® 3.1
Message 70 of 79
Mrgoodall
Star

Re: CM1000 Xfinity issues

CM1000 statusCM1000 statusIs this right after a boot and a reset of the modem? Because mine looks nothing like that.

Message 71 of 79
DarrenM
NETGEAR Moderator

Re: CM1000 Xfinity issues

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

Message 72 of 79
NBCGLX
Guide

Re: CM1000 Xfinity issues


@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


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.

Model: CM1000|DOCSIS® 3.1
Message 73 of 79
DarrenM
NETGEAR Moderator

Re: CM1000 Xfinity issues

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

 

DarrenM

Message 74 of 79
Mrgoodall
Star

Re: CM1000 Xfinity issues

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. 

Model: CM1000|DOCSIS® 3.1
Message 75 of 79
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