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Random Internet Loss

New Poster

Random Internet Loss

I have been getting a random loss of internet for the last year or so. I've just been living with it as it only lasts for a minute or 2. Now since moving to DOCSIS 3.1 and Gig internet it seems to have gotten worse. 

 

I have a Netgear CM1100, I had one of the Comcast DOCSIS 3.1 modems, and they both had similar problems. I've even replaced the router to no avail. It happened again today so I figured I'd go hunting for more info or help as the last time I contacted Comcast it cleared up before they got back to me. Here's what my modem shows, I would very much appreciate any help or a direction to be pointed in.

 

 

Frequency start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 639000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enable BPI+
IP Provisioning Mode Honor MDD IPv6 only

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 25 639000000 Hz -1.7 dBmV 39.1 dB 1470209007 1608 1306
2 Locked QAM256 1 489000000 Hz -1.2 dBmV 40.0 dB 1387548099 3169 2463
3 Locked QAM256 2 495000000 Hz -1.2 dBmV 40.0 dB 1451559254 130605 82249
4 Locked QAM256 3 507000000 Hz -1.1 dBmV 40.1 dB 1414001622 85663 3621
5 Locked QAM256 4 513000000 Hz -1.2 dBmV 40.0 dB 1451532915 148414 79018
6 Locked QAM256 5 519000000 Hz -1.4 dBmV 39.8 dB 1451530307 153448 61380
7 Locked QAM256 6 525000000 Hz -1.6 dBmV 39.8 dB 1451543018 154054 65127
8 Locked QAM256 7 531000000 Hz -1.8 dBmV 39.8 dB 1451534185 168006 69646
9 Locked QAM256 8 537000000 Hz -1.8 dBmV 39.7 dB 1451549307 172240 68695
10 Locked QAM256 9 543000000 Hz -2.0 dBmV 39.6 dB 1451564797 168752 72023
11 Locked QAM256 10 549000000 Hz -2.2 dBmV 39.7 dB 1451563011 188978 82622
12 Locked QAM256 11 555000000 Hz -2.2 dBmV 39.6 dB 1451543519 210273 72335
13 Locked QAM256 12 561000000 Hz -2.0 dBmV 39.7 dB 1451550513 208979 81344
14 Locked QAM256 13 567000000 Hz -1.9 dBmV 39.5 dB 1451529049 233623 74776
15 Locked QAM256 14 573000000 Hz -2.0 dBmV 39.4 dB 1451505868 257882 62366
16 Locked QAM256 15 579000000 Hz -1.9 dBmV 39.5 dB 1451499451 268310 64277
17 Locked QAM256 16 585000000 Hz -1.6 dBmV 39.4 dB 386389871 255742 62882
18 Locked QAM256 17 591000000 Hz -1.5 dBmV 39.5 dB 386377977 273473 53325
19 Locked QAM256 18 597000000 Hz -1.5 dBmV 39.5 dB 386364623 292185 50430
20 Locked QAM256 19 603000000 Hz -1.4 dBmV 39.4 dB 386350349 312961 45836
21 Locked QAM256 20 609000000 Hz -1.2 dBmV 39.4 dB 386326996 339612 28714
22 Locked QAM256 21 615000000 Hz -1.0 dBmV 39.4 dB 386356217 319210 38070
23 Locked QAM256 22 621000000 Hz -0.9 dBmV 39.4 dB 369565081 300906 29658
24 Locked QAM256 23 627000000 Hz -1.5 dBmV 39.3 dB 386333033 353228 29766
25 Locked QAM256 24 633000000 Hz -1.7 dBmV 39.1 dB 386342770 349367 25719
26 Locked QAM256 26 645000000 Hz -1.8 dBmV 38.7 dB 386302547 399643 43487
27 Locked QAM256 27 651000000 Hz -2.1 dBmV 38.6 dB 386205586 498133 18140
28 Locked QAM256 28 657000000 Hz -2.4 dBmV 38.5 dB 386189913 520570 14862
29 Locked QAM256 29 663000000 Hz -2.1 dBmV 38.6 dB 386176018 539436 8212
30 Locked QAM256 30 669000000 Hz -1.7 dBmV 38.7 dB 386150588 557439 6072
31 Locked QAM256 31 675000000 Hz -1.6 dBmV 38.5 dB 386122936 571319 11723
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 35700000 Hz 53.8 dBmV
2 Locked ATDMA 2 29200000 Hz 52.3 dBmV
3 Locked ATDMA 3 22700000 Hz 50.8 dBmV
4 Locked ATDMA 4 16200000 Hz 51.3 dBmV
5 Not Locked Unknown 0 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Hz 0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
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, 255 159 690000000 Hz -0.5 dBmV 37.5 dB 1366 ~ 2729 26187118228 19844120776 9
2 Not Locked 0, 255 0 0 Hz -0.4 dBmV 0.0 dB 0 ~ 4095 0 0 0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked Unknown 0 0 Hz 0 dBmV
2 Not Locked Unknown 0 0 Hz 0 dBmV

Current System Time: Sat Mar 23 13:44:48 2019 
Expert

Re: Random Internet Loss

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, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

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.




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New Poster

Re: Random Internet Loss

This is in an apartment and coming straight from the wall to modem. I tried the other outlets in my apartment with similar results. Internet would work but eventually I'd lose connection as the modem is rebooting. I've been surviving on the open xFinity hotspot of neightbors and it seems to be stable. I've been meaning to come back to this but life and family issues came first. Where would I go to book a tech to check? 

Expert

Re: Random Internet Loss

Call 1-800-comcast.



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? Mark the post as Best Answer!
Official Employee

Re: Random Internet Loss

Hey there, SmokieRat! Thank you for reaching out here. I would be more than happy to help with the internet connectivity issues you're running into. I get how important it is to have reliable service! Please feel free to send me a PM with your first and last name to take a look at this further together. 

To send me a Private Message, please click my name “ComcastAlly” and click “send a message.”


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Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
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