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user_ca27d5
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6 Messages

Saturday, April 29th, 2023 4:16 PM

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Unstable Internet, Speed now only 400-500 Mbps tops (pay for 1200Mbps) - Need help

​Hi, I've been experiencing fairly regular (daily) Internet outages. I've also noticed lately also that my top seeds have dropped by half. I used to get 900-1000Mbps but recently I can only seem to get 400-500Mbps. As noted I'm paying for 1200. I logged into my Netgear CM1200 and noticed log errors that seem to suggest the modem is loosing it's link of some sort. Also, the log issues include Critical (3) and Notice (6). I have a laptop connected to my CM1200 and​

​This Xfinity network instability on my network occurs a lot lately, near daily where I have to reset my cable model to re-establish connectivity.​

​Nearly everything I have depends now on a stable and fast internet connection. ​

​I want to know the best course to take to get this looked at and resolved​

​After clearing the log page and resetting the modem below is the start of some new entries.​

​Can anyone explain whats happening?  (I did remove my CM MAC and put xx:xx:xx:xx:xx:xx) for safety reasons​

​After the logs are my current modem connection config​

​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​
​Time​ ​Priority​ ​Description​
​Fri Apr 28 15:45:02 2023​ ​Notice (6)​ ​CM-STATUS message sent. Event Type Code: 5; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;​
​Fri Apr 28 15:44:49 2023​ ​Notice (6)​ ​DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;​
​Fri Apr 28 15:44:44 2023​ ​Notice (6)​ ​TLV-11 - unrecognized OID;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;​
​Time Not Established​ ​Notice (6)​ ​Honoring MDD; IP provisioning mode = IPv6​
​Time Not Established​ ​Critical (3)​ ​No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;​
​Time Not Established​ ​Critical (3)​ ​SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;​
​Thu Apr 27 17:02:00 2023​ ​Notice (6)​ ​CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;​
​Thu Apr 27 17:01:29 2023​ ​Notice (6)​ ​CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;​
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​Startup Procedure​
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​Procedure​ ​Status​ ​Comment​
​Acquire Downstream Channel​ ​471000000 Hz​ ​Locked​
​Connectivity State​ ​OK​ ​Operational​
​Boot State​ ​OK​ ​Operational​
​Security​ ​Enabled​ ​BPI+​
​IP Provisioning Mode​ ​Honor MDD​ ​honorMdd(4)​
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​   ​
​Downstream Bonded Channels​
​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​
​Channel​ ​Lock Status​ ​Modulation​ ​Channel ID​ ​Frequency​ ​Power​ ​SNR​ ​Correctables​ ​Uncorrectables​
​1​ ​Locked​ ​QAM256​ ​20​ ​471000000 Hz​ ​0.6 dBmV​ ​40.5 dB​ ​13​ ​0​
​2​ ​Locked​ ​QAM256​ ​17​ ​453000000 Hz​ ​1.3 dBmV​ ​40.7 dB​ ​2​ ​0​
​3​ ​Locked​ ​QAM256​ ​18​ ​459000000 Hz​ ​0.6 dBmV​ ​40.5 dB​ ​6​ ​0​
​4​ ​Locked​ ​QAM256​ ​19​ ​465000000 Hz​ ​0.4 dBmV​ ​40.5 dB​ ​8​ ​0​
​5​ ​Locked​ ​QAM256​ ​21​ ​477000000 Hz​ ​0.6 dBmV​ ​40.6 dB​ ​5​ ​0​
​6​ ​Locked​ ​QAM256​ ​22​ ​483000000 Hz​ ​0.3 dBmV​ ​40.5 dB​ ​9​ ​0​
​7​ ​Locked​ ​QAM256​ ​23​ ​489000000 Hz​ ​0.5 dBmV​ ​40.6 dB​ ​8​ ​0​
​8​ ​Locked​ ​QAM256​ ​24​ ​495000000 Hz​ ​0.5 dBmV​ ​40.7 dB​ ​2​ ​0​
​9​ ​Locked​ ​QAM256​ ​25​ ​501000000 Hz​ ​0.1 dBmV​ ​40.4 dB​ ​1​ ​0​
​10​ ​Locked​ ​QAM256​ ​26​ ​507000000 Hz​ ​0.2 dBmV​ ​40.5 dB​ ​1​ ​0​
​11​ ​Locked​ ​QAM256​ ​27​ ​513000000 Hz​ ​0.4 dBmV​ ​40.6 dB​ ​3​ ​0​
​12​ ​Locked​ ​QAM256​ ​28​ ​519000000 Hz​ ​0.3 dBmV​ ​40.6 dB​ ​2​ ​0​
​13​ ​Locked​ ​QAM256​ ​29​ ​525000000 Hz​ ​-0.2 dBmV​ ​40.5 dB​ ​4​ ​0​
​14​ ​Locked​ ​QAM256​ ​30​ ​531000000 Hz​ ​0.1 dBmV​ ​40.5 dB​ ​2​ ​0​
​15​ ​Locked​ ​QAM256​ ​31​ ​537000000 Hz​ ​-0.1 dBmV​ ​40.5 dB​ ​1​ ​0​
​16​ ​Locked​ ​QAM256​ ​32​ ​543000000 Hz​ ​-0.6 dBmV​ ​40.3 dB​ ​3​ ​0​
​17​ ​Locked​ ​QAM256​ ​33​ ​549000000 Hz​ ​-0.4 dBmV​ ​40.4 dB​ ​2​ ​0​
​18​ ​Locked​ ​QAM256​ ​34​ ​555000000 Hz​ ​-0.2 dBmV​ ​40.5 dB​ ​4​ ​0​
​19​ ​Locked​ ​QAM256​ ​35​ ​561000000 Hz​ ​-0.2 dBmV​ ​40.5 dB​ ​3​ ​0​
​20​ ​Locked​ ​QAM256​ ​36​ ​567000000 Hz​ ​-0.4 dBmV​ ​40.5 dB​ ​1​ ​0​
​21​ ​Locked​ ​QAM256​ ​37​ ​573000000 Hz​ ​0 dBmV​ ​40.5 dB​ ​1​ ​0​
​22​ ​Locked​ ​QAM256​ ​38​ ​579000000 Hz​ ​-0.2 dBmV​ ​40.5 dB​ ​1​ ​0​
​23​ ​Locked​ ​QAM256​ ​39​ ​585000000 Hz​ ​-0.5 dBmV​ ​40.5 dB​ ​2​ ​0​
​24​ ​Locked​ ​QAM256​ ​40​ ​591000000 Hz​ ​-0.6 dBmV​ ​40.5 dB​ ​1​ ​0​
​25​ ​Locked​ ​QAM256​ ​41​ ​597000000 Hz​ ​0 dBmV​ ​40.6 dB​ ​0​ ​0​
​26​ ​Locked​ ​QAM256​ ​42​ ​603000000 Hz​ ​-0.7 dBmV​ ​40.4 dB​ ​2​ ​0​
​27​ ​Locked​ ​QAM256​ ​43​ ​609000000 Hz​ ​-0.9 dBmV​ ​40.4 dB​ ​1​ ​0​
​28​ ​Locked​ ​QAM256​ ​44​ ​615000000 Hz​ ​-0.6 dBmV​ ​40.5 dB​ ​0​ ​0​
​29​ ​Locked​ ​QAM256​ ​45​ ​621000000 Hz​ ​-0.6 dBmV​ ​40.5 dB​ ​1​ ​0​
​30​ ​Locked​ ​QAM256​ ​46​ ​627000000 Hz​ ​-1.1 dBmV​ ​40.2 dB​ ​1​ ​0​
​31​ ​Locked​ ​QAM256​ ​47​ ​633000000 Hz​ ​-1 dBmV​ ​40.3 dB​ ​7​ ​0​
​32​ ​Not Locked​ ​Unknown​ ​0​ ​0 Hz​ ​0.0 dBmV​ ​0.0 dB​ ​0​ ​0​
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​Upstream Bonded Channels​
​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​
​Channel​ ​Lock Status​ ​US Channel Type​ ​Channel ID​ ​Symbol Rate​ ​Frequency​ ​Power​
​1​ ​Locked​ ​ATDMA​ ​1​ ​5120 Ksym/sec​ ​16400000 Hz​ ​38 dBmV​
​2​ ​Locked​ ​ATDMA​ ​2​ ​5120 Ksym/sec​ ​22800000 Hz​ ​39.5 dBmV​
​3​ ​Locked​ ​ATDMA​ ​3​ ​5120 Ksym/sec​ ​29200000 Hz​ ​40 dBmV​
​4​ ​Locked​ ​ATDMA​ ​4​ ​5120 Ksym/sec​ ​35600000 Hz​ ​40.5 dBmV​
​5​ ​Not Locked​ ​Unknown​ ​0​ ​0 Ksym/sec​ ​0 Hz​ ​0.0 dBmV​
​6​ ​Not Locked​ ​Unknown​ ​0​ ​0 Ksym/sec​ ​0 Hz​ ​0.0 dBmV​
​7​ ​Not Locked​ ​Unknown​ ​0​ ​0 Ksym/sec​ ​0 Hz​ ​0.0 dBmV​
​8​ ​Not Locked​ ​Unknown​ ​0​ ​0 Ksym/sec​ ​0 Hz​ ​0.0 dBmV​
​ ​
​   ​
​Downstream OFDM Channels​
​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​
​Channel​ ​Lock​
​Status​		 ​Modulation /​
​Profile ID​		 ​Channel​
​ID​		 ​Frequency​ ​Power​ ​SNR /​
​MER​		 ​Active Subcarrier​
​Number Range​		 ​Unerrored​
​Codewords​		 ​Correctable​
​Codewords​		 ​Uncorrectable​
​Codewords​
​1​ ​Locked​ ​0 ,1 ,2 ,3​ ​48​ ​685000000 Hz​ ​-1.7 dBmV​ ​39.9 dB​ ​1108 ~ 2987​ ​880092858​ ​868622359​ ​0​
​2​ ​Not Locked​ ​0​ ​0​ ​0 Hz​ ​0 dBmV​ ​0.0 dB​ ​0 ~ 4095​ ​0​ ​0​ ​0​
​ ​
​   ​
​Upstream OFDMA Channels​
​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​
​Channel​ ​Lock Status​ ​Modulation / Profile ID​ ​Channel ID​ ​Frequency​ ​Power​
​1​ ​Not Locked​ ​0​ ​0​ ​0 Hz​ ​0 dBmV​
​2​ ​Not Locked​ ​0​ ​0​ ​0 Hz​ ​0 dBmV​
​ ​
​   ​
​Extended Upstream Transmit Power​
​Enable Extended Upstream Transmit Power​
​ ​
​   ​
​Current System Time:Sat Apr 29 08:06:22 2023​
​System Up Time:16:22:19​
​ ​

Question

 • 

Updated 

2 years ago

 • Edited

1.1K

2

0

EG

Expert

 • 

110K Messages

2 years ago

@user_ca27d5 

You need to edit out the CMTS MAC addresses as well. Their forum bot considers them to be personal information too. Your post is flagged as "Private".

2

0

user_ca27d5

Visitor

 • 

6 Messages

@EG​ Thx. didn't think they could but appreciate the advise. Please review if you can.

2 years ago

0

CCDaniel

Problem Solver

 • 

606 Messages

 

@user_ca27d5 Thank you fro reachinf our. I would like to take a look at the provisionig of the Modem and your account. Can you send us a direct message.

To send a direct message:

Click "Sign In" if necessary

• Click the "Direct messaging" icon near the top right of the page

• Click the "New message" (pencil and paper) icon

• Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line

• Type your message in the text area near the bottom of the window

• Press Enter to send it

 

I no longer work for Comcast.

2 years ago

0

EG

Expert

 • 

110K Messages

2 years ago

Even though the signal status values looked OK at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) / an upstream channel / return path impairment somewhere.


There are other signal stat values that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


I'm going to escalate your issue to the Comcast corporate employees (The Digital Care Team) who are available to these boards. They will be able to poll the CMTS (Cable Modem Termination System) to check for any real-time degradation and / or error reports, see your node / cable plant, and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll the CMTS for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !

3

0

user_ca27d5

Visitor

 • 

6 Messages

@EG​ I have done all I can. I contacted a rep via private and they warned me that if the issue was in my home cabling, etc it would cost me. I went as far as took my Modem out to the location the drop comes into the house, connected it directly to my CM and ran it straight from there. Same results, same error msgs. Speed hits about 480 tops. I have been in this house for 4 years and at least one prior occasion after it seems a tech may changes to the main box down the street I started to have issues. For the first 2 years here I had ZERO problems. Now it's constant. 

Thx

Neil

2 years ago

0

user_ca27d5

Visitor

 • 

6 Messages

While waiting for support from the Xfinity online team, I have tried everything I can to see if my performance gets better.

I checked all cabling up to the house entry cable. I connected my modem directly to the cable from the street. I've tried a diff. high-end Netgear Gig Routers. Nothing but a computer and a router connected. In all case my performance is about 460-480 Mbps. Not getting any connection losses either. To me I am starting to think I am being throttled.

2 years ago

0

user_ca27d5

Visitor

 • 

6 Messages

This is what I just received from the Xfinity support tech.  BTW, to comment on this online support if I may, They respond very slowly and diff. techs respond in the same subject. So far on the same open discussion I've had 5 diff techs reply to the same conversations. 

The last tech responded as I cut/pasted below. She misread - I did not say I changed my modem, I tried a diff gateway/router. Also, I am very certain I know my CM1200 can do 900+ as I used to get those numbers. But to wait this long to get what I already know and all searchable content, yet not help with my issue saddens me.

Last response from Xfinity tech #5 tonight

I assure you we do not throttle our customers at all there is no need, but there may definitely be an underlying issue or reason for the speed loss. I was doing some digging for you and to start the modem I see you have on file and has been online is the Netgear CM1200. I do not see that any other equipment has been activated on your account as our system does record each activated piece of equipment including customer modems. When you say you activated a different modem could you confirm the MAC address for me and if you still have that modem plugged in? I would be happy to check to make sure that this new modem or a different modem is correctly activated for you. Also, if you are using the Netgear CM1200 this is rated for speeds up to 949Mbps. You can confirm that here https://www.xfinity.com/support/devices/#details with that the speed is only using a hardwired connection. The speed currently active on your plan is 1200mbps, when you have a speed active on your account that your modem does not support that does cause lots of connection issues mainly you receive a lower speed both the modem and speed on your plan due to the modem being overworked and not capable of supporting the full speed. You can use the same link I provided above to see what modems do support your current 1200Mbps package, or we can definitely look into lower speed options to make sure you are getting what you are paying for.

2 years ago

0

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