Visitor

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5 Messages

Monday, September 29th, 2025

High Latency and Disconnects Every Night

Hi,

For several weeks now I have been getting high latency and disconnects every night. The internet disruptions begin consistently each night in the 9–10 PM window. I have replaced my modem in an attempt to see if that made a difference, but it did not improve the situation.

I can see from the modem logs that the disconnects appear like

There are also many instances of these messages

09/29/2025 08:11:54 Notice CM-STATUS message sent. Event Type Code: 5; Chan ID: 42; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

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Expert

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114.2K Messages

1 month ago

What do the modem's signal status values look like ? Try getting them here; http://192.168.100.1 or here http://10.0.0.1 


Please copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level* numbers and paste them into your next post.


What is the exact make and model number of the modem / gateway device ?

Visitor

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5 Messages

1 month ago

Modem: ARRIS SURFboard S34

Startup Procedure
Procedure  Status  Comment
Acquire Downstream Channel  543000000 Hz  Locked
Connectivity State  OK  Partial Service (DS only)
Boot State  OK  Partial Service (DS only)
Configuration File  OK  
Security  Enabled  BPI+
DOCSIS Network Access Enabled  Allowed  

Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
28 Locked 256QAM 543000000 Hz -3.4 dBmV 39.0 dB 1254 421
17 Not Locked Unknown 0 Hz -48.9 dBmV 13.7 dB 0 390164558
18 Not Locked Unknown 0 Hz -48.7 dBmV 8.6 dB 0 392021861
19 Not Locked Unknown 0 Hz -48.7 dBmV 15.6 dB 0 391626423
20 Not Locked Unknown 0 Hz -49.3 dBmV 14.1 dB 0 391101416
21 Not Locked Unknown 0 Hz -50.3 dBmV 16.7 dB 0 390331527
22 Not Locked Unknown 0 Hz -52.3 dBmV 4.4 dB 0 391553091
23 Not Locked Unknown 0 Hz -50.4 dBmV 7.8 dB 0 394678943
24 Not Locked Unknown 0 Hz -22.7 dBmV 17.1 dB 0 393428223
25 Locked 256QAM 525000000 Hz -9.3 dBmV 36.6 dB 45951 151473
26 Locked 256QAM 531000000 Hz -8.8 dBmV 38.6 dB 133 125
27 Locked 256QAM 537000000 Hz -6.7 dBmV 38.6 dB 1112 1259
29 Locked 256QAM 549000000 Hz -1.8 dBmV 40.9 dB 73 28
30 Locked 256QAM 555000000 Hz -2.2 dBmV 40.9 dB 89 93
31 Locked 256QAM 561000000 Hz -2.5 dBmV 40.9 dB 194 974
32 Locked 256QAM 567000000 Hz -2.9 dBmV 40.9 dB 97 59
33 Locked 256QAM 573000000 Hz -3.0 dBmV 40.4 dB 192 1112
34 Locked 256QAM 579000000 Hz -2.4 dBmV 40.4 dB 37 22
35 Locked 256QAM 585000000 Hz -1.9 dBmV 40.4 dB 47 90
36 Locked 256QAM 591000000 Hz -1.3 dBmV 40.4 dB 87 47
37 Locked 256QAM 597000000 Hz -0.8 dBmV 40.9 dB 94 64
38 Locked 256QAM 603000000 Hz -0.2 dBmV 40.4 dB 71 67
39 Locked 256QAM 609000000 Hz -0.4 dBmV 40.9 dB 67 139
40 Locked 256QAM 615000000 Hz -0.8 dBmV 40.4 dB 94 3
41 Locked 256QAM 621000000 Hz -1.2 dBmV 40.9 dB 111 58
42 Locked 256QAM 627000000 Hz -1.8 dBmV 40.4 dB 248 64
43 Locked 256QAM 633000000 Hz -2.3 dBmV 40.4 dB 595 1032
44 Locked 256QAM 639000000 Hz -2.8 dBmV 40.4 dB 92 10
45 Locked 256QAM 645000000 Hz -3.1 dBmV 40.9 dB 102 40
46 Locked 256QAM 651000000 Hz -3.6 dBmV 40.4 dB 131 67
47 Locked 256QAM 657000000 Hz -3.9 dBmV 40.4 dB 463 255
48 Locked OFDM PLC 688000000 Hz -4.5 dBmV 41.0 dB 1188798467 1165




Upstream Bonded Channels
Channel ID Lock Status US Channel Type Frequency Width Power
1 Locked SC-QAM 16400000 Hz 6400000 47.8 dBmV
4 Locked SC-QAM 35600000 Hz 6400000 51.0 dBmV
3 Locked SC-QAM 29200000 Hz 6400000 50.3 dBmV
2 Locked SC-QAM 22800000 Hz 6400000 48.8 dBmV

Expert

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114.2K Messages

29 days ago

There are RF signal / connection quality problems. Downstream channels 17 through 24 are not even locking in. And some that are locking in are on the low / weak side or out of spec. And the upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/reconfigured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.

Also, check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, or animal chews.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.


Good luck with it !

Visitor

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5 Messages

29 days ago

These issues started suddenly around the end of August and there have been no changes to the wiring within my house. Their is a single coax from demarc to the modem. Can I get someone out to check the wiring upstream? 

Expert

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114.2K Messages

@where_did_the_data_go​ 

If there is nothing more that can be done to improve the connection quality, then you'll need a tech visit as stated. 


Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it up to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. And if the problem is found to be on their side of the demarcation point, there will not be any charge.


Good luck !

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Official Employee

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1.6K Messages

28 days ago

Good Afternoon, @where_did_the_data_go! Thank you so much for taking the time to reach out to us here on the Xfinity Forums. I completely understand the need for a solid connection within the home, and want to make sure your services are working as intended. Thank you so much @EG for sharing all your awesome knowledge, and helping dive into troubleshooting right away. 

 

Just to ensure we are on the same page, did you swap out the coax cable that is from your device to the wall outlet already? If so, we would want to dive deeper into the account with you to see about our next steps. Please let us know. 

Visitor

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5 Messages

Hi,

A tech came out and found a loose connection at the pole. This has fixed the signal issue and the nightly disconnects have stopped, however I still see high latency every night. I have tried changing cables to the modem. The coax that that connects to the modem runs directly to the demarc box and connects directly to the coax from the pole.

Let me know if you need me to get more information with respect to when the latency issues arise and the measured latency.

Thanks

Official Employee

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2.6K Messages

@where_did_the_data_go

Thanks for the update, what I recommend you do when you're having the connection issues is to jump on the Xfinity app and go through some troubleshooting steps so it can see if it can detect an issue, you'll work with the awesome chat assistant to do some remote troubleshooting to see if that issue can be fixed remotely and if it can't it'll connect you with one of our awesome chat agents

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Visitor

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5 Messages

@XfinityOrlandoM​ Tried several times with the chat app and got nowhere. It kept saying everything was fine. It scheduled another tech visit.

This is what it looks like during an event. Packet loss and high latency to the first hop in the route.

(edited)

Official Employee

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2.6K Messages

 

where_did_the_data_go Thanks for the response and for being proactive trying what we suggested. I am happy to work together and look more into the account to see the status of your connection. Please send us a DM with your first name and service address so we can get started. 

Here's the detailed steps to direct message us:

• Click "Sign In" if necessary

• Click the "Direct Message" icon (upper right corner of this 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

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

• Press Enter to send your message

(edited)

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Expert

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114.2K Messages

@where_did_the_data_go @XfinityJorge 

Please circle back here and post any possible solutions for the issue here in these open public forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

Visitor

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19 Messages

13 days ago

Mine disconnects every morning. 

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