user_rk2410's profile

Visitor

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4 Messages

Monday, October 7th, 2024 2:51 PM

Intermittent Connectivity Issues

Over the past few weeks, I've been having what seem to be internet connection drops throughout the day.  Looking at the modem logs today, I see the following types of logs.  How can this be remedied?

CM-STATUS message sent. Event Type Code: 5; Chan ID: 24; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC= CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1; 10/07/2024 09:39:35 Notice
No Ranging Response received - T3 time-out;[Edited: "Personal Information"];CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1; 10/07/2024 09:39:32 Critical
CM-STATUS message sent. Event Type Code: 2; Chan ID: 42; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC= CMTS-MAC= CM-QOS=1.1;CM-VER=3.1; 10/07/2024 09:39:31 Notice
No Ranging Response received - T3 time-out;CM-MAC= ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1; 10/07/2024 09:39:31 Critical
CM-STATUS message sent. Event Type Code: 5; Chan ID: 24; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC= ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1; 10/07/2024 09:38:23 Notice
No Ranging Response received - T3 time-out;CM-MAC= ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1; 10/07/2024 09:37:59 Critical

Expert

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106.9K Messages

29 days ago

Please also 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.

Visitor

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4 Messages

Appreciate your assistance.

Downstream QAM

Index Frequency (MHz) Power Level (dBmV) SNR (dB) Modulation Lock Status
17 519 -2.200001 38.983261 QAM256 Locked
14 501 -1.500000 40.946209 QAM256 Locked
15 507 -1.900002 40.366287 QAM256 Locked
16 513 -2.099998 38.983261 QAM256 Locked
18 525 -2.200001 40.366287 QAM256 Locked
19 531 -2.200001 40.366287 QAM256 Locked
20 537 -1.700001 40.366287 QAM256 Locked
21 543 -1.599998 40.946209 QAM256 Locked
22 555 -1.599998 38.605377 QAM256 Locked
23 561 -1.599998 38.983261 QAM256

Locked

24 567 -1.900002 35.083549 QAM256 Locked
26 573 -2.099998 34.345688 QAM256 Locked
27 579 -2.200001 38.983261 QAM256 Locked
28 585 -2.500000 38.605377 QAM256 Locked
29 591 -2.500000 38.983261 QAM256 Locked
30 597 -2.400002 40.366287 QAM256 Locked
31 603 -2.500000 40.366287 QAM256 Locked
32 609 -2.400002 38.983261 QAM256 Locked
33 615 -2.500000 40.366287 QAM256 Locked
34 621 -2.599998 40.366287 QAM256 Locked
35 627 -3.200001 38.983261 QAM256 Locked
36 633 -3.700001 38.983261 QAM256 Locked
37 639 -3.900002 38.983261 QAM256 Locked
38 645 -3.599998 38.605377 QAM256 Locked
39 651 -3.599998 38.983261 QAM256 Locked
40 657 -2.900002 38.605377 QAM256 Locked
41 663 -2.200001 38.983261 QAM256 Locked
42 669 -2.000000 38.983261 QAM256 Locked
43 675 -2.000000 40.366287 QAM256 Locked
44 681 -2.500000 38.983261 QAM256 Locked
45 687 -3.200001 38.605377 QAM256 Locked

Upstream QAM

Index Frequency (MHz) Power Level (dBmV) Channel Type Symbol Rate (KSym/sec) Modulation Lock Status
42 22.8 59.020599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked
44 35.6 47.520599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked
43 29.2 55.520599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked

Expert

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106.9K Messages

29 days ago

The upstream power is way out of spec on channels 42 & 43 !! 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/re-configured. 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, etc.

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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4 Messages

@EG​  - I very much appreciate your assistance.

I was able to remove one splitter, no longer necessary since the cable now only feeds my router (no longer receiving TV from Comcast).

Pretty radical change on the Downstream Power Levels, less impactful on 2 of the 3 upstream channels.

Downstream QAM

Index Frequency (MHz) Power Level (dBmV) SNR (dB) Modulation Lock Status
17 519 4.599998 33.956509 QAM256 Locked
14 501 5.099998 34.345688 QAM256 Locked
15 507 4.699997 33.956509 QAM256 Locked
16 513 4.300003 33.486542 QAM256 Locked
18 525 4.599998 33.956509 QAM256 Locked
19 531 4.699997 34.345688 QAM256 Locked
20 537 5.300003 34.925610 QAM256 Locked
21 543 5.400002 35.083549 QAM256 Locked
22 555 5.199997 33.956509 QAM256 Locked
23 561 5.099998 33.834164 QAM256 Locked
24 567 4.900002 33.486542 QAM256 Locked
26 573 4.599998 33.486542 QAM256 Locked
27 579 4.300003 33.956509 QAM256 Locked
28 585 4.199997 34.483570 QAM256 Locked
29 591 4.199997 34.345688 QAM256 Locked
30 597 4.400002 34.345688 QAM256 Locked
31 603 4.400002 33.376591 QAM256 Locked
32 609 4.500000 33.956509 QAM256 Locked
33 615 4.599998 33.062504 QAM256 Locked
34 621 4.500000 33.376591 QAM256 Locked
35 627 4.000000 32.584778 QAM256 Locked
36 633 3.500000 31.915308 QAM256 Locked
37 639 3.299999 31.915308 QAM256 Locked
38 645 3.400002 32.584778 QAM256 Locked
39 651 3.500000 31.915308 QAM256 Locked
40 657 4.099998 32.676208 QAM256 Locked
41 663 4.599998 33.376591 QAM256 Locked
42 669 4.800003 33.376591 QAM256 Locked
43 675 4.800003 33.486542 QAM256 Locked
44 681 4.300003 32.584778 QAM256 Locked
45 687 3.700001 32.237156 QAM256

Locked

Upstream QAM

Index Frequency (MHz) Power Level (dBmV) Channel Type Symbol Rate (KSym/sec) Modulation Lock Status
42 22.8 59.020599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked
44 35.6 47.520599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked
43 29.2 48.770599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked

FWIW - I've pasted links to the before and after DOCSIS Spectrum Analyzer Data charts

AFTER

https://drive.google.com/file/d/12Zwo030uW0uBSmQn-S0e3HWQbuKTFbtj/view?usp=sharing,

BEFORE

https://drive.google.com/file/d/1vDRcrUmrD9XxXmoDGUCTVoLmW5Suz9NG/view?usp=sharing

The most important thing, so far, is no noticeable drops of service for the last two hours, no new modem event logs.  Fingers crossed.

Thanks!!

Expert

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106.9K Messages

28 days ago

Can't open those links. Need your permission. The upstream power is still way out of spec on channel 42. And the upstream channels have fallen back to being 16 QAM instead of being at 64 QAM. 16 QAM is a more robust modulation scheme, but it has less bandwidth capacity. A noise impairment causes that. And the downstream channel SNR values are very low / out of spec as well. There is spurious noise leaking into the line(s) somewhere. 

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.

(edited)

Visitor

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4 Messages

@EG​ Thanks again for your assistance.

I probably should have known to do power cycle the CM after reconnecting cables and splitters.  I've done that now and the numbers are very different.  Still seeing the Upstream at 16QAM.

I'd very must appreciate a quick review.  Also, the speedtest is exceeding the Connect More specs.  (350MB/s download, 23MB/s upload).

Downstream QAM

Index Frequency (MHz) Power Level (dBmV) SNR (dB) Modulation Lock Status
17 519 4.900002 40.946209 QAM256 Locked
14 501 5.300003 40.366287 QAM256 Locked
15 507 4.900002 40.366287 QAM256 Locked
16 513 4.599998 40.946209 QAM256 Locked
18 525 4.800003 40.946209 QAM256 Locked
19 531 4.800003 40.366287 QAM256 Locked
20 537 5.400002 40.946209 QAM256 Locked
21 543 5.599998 40.946209 QAM256 Locked
22 555 5.500000 40.366287 QAM256 Locked
23 561 5.400002 40.946209 QAM256 Locked
24 567 5.099998 38.983261 QAM256 Locked
26 573 4.900002 40.366287 QAM256 Locked
27 579 4.599998 40.366287 QAM256 Locked
28 585 4.400002 38.983261 QAM256 Locked
29 591 4.400002 40.366287 QAM256 Locked
30 597 4.599998 40.366287 QAM256 Locked
31 603 4.599998 40.366287 QAM256 Locked
32 609 4.800003 38.983261 QAM256 Locked
33 615 4.900002 40.366287 QAM256 Locked
34 621 4.800003 40.946209 QAM256 Locked

35 627 4.099998 38.983261 QAM256 Locked
36 633 3.700001 38.983261 QAM256 Locked
37 639 3.500000 38.983261 QAM256 Locked
38 645 3.500000 38.983261 QAM256 Locked
39 651 3.799999 38.983261 QAM256 Locked
40 657 4.300003 38.605377 QAM256 Locked
41 663 4.800003 38.983261 QAM256 Locked
42 669 5.000000 38.983261 QAM256 Locked
43 675 5.000000 40.366287 QAM256 Locked
44 681 4.500000 40.366287 QAM256 Locked
45 687 4.000000 38.983261 QAM256 Locked

Upstream QAM

Index Frequency (MHz) Power Level (dBmV) Channel Type Symbol Rate (KSym/sec) Modulation Lock Status
42 22.8 36.270599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked
44 35.6 36.270599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked
43 29.2 36.270599 US_TYPE_ATDMA 5120 KSym/sec 16QAM Locked

Also, EG, I'm seeing different event logs that look like this (I've xx'd out the MAC addresses).  Any explanation?

UTOPIA: lan.dhcpserver action: old MAC: bc:d7:xx IP: 192.168.0.69 VendorClass: 10/08/2024 12:44:01 Notice
UTOPIA: lan.dhcpserver action: old MAC: 04:5d:xx IP: 192.168.0.60 VendorClass: android-dhcp-9 10/08/2024 12:43:53 Notice
UTOPIA: lan.dhcpserver action: old MAC: bc:d7:xx IP: 192.168.0.69 VendorClass: 10/08/2024 12:43:02 Notice
UTOPIA: lan.dhcpserver action: old MAC: 04:5d:xx IP: 192.168.0.60 VendorClass: android-dhcp-9 10/08/2024 12:42:52 Notice

Thanks so much.

Official Employee

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1.4K Messages

It seems like service is working better @user_rk2410. If the issue comes back please let us know. We can always help with getting an appointment scheduled if needed.

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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106.9K Messages

28 days ago

Ah. Much better ! But the upstream channels should have gone back to being 64 QAM. There's probably still an upstream / return path only impairment somewhere. I would consider getting a tech out to investigate.

(edited)

Expert

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106.9K Messages

28 days ago

@user_rk2410 

Those messages are not modem component RF signal related. They are LAN / router component / DHCP related.

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