Intermitten Drops - Gigabit Internet - Event Type 16 Errors in Modem Logs

What do the modem's signal stats look like ? 

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.

Please post those error log entries as well in their entirety (copy and paste them, don't post a screenshot) but redact the CM MAC and the CMTS MAC addresses for your privacy. They are considered to be personal information. The posting of personally identifying information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically.

Is this with a router / WiFi connection in the mix ?

The intermittent connectivity issues occur on both devices connected to Wifi (via Google Wifi AC1200 Dual-Band) as well as those connected directly via ethernet cable (router)

The downstream power is on the low / weak side and it may be intermittently fluctuating even lower to out of spec levels. The OFDM channel is already out of spec. It appears that a condition exists that is called *cable tilt*. This is where the higher frequency downstream channel's power levels roll-off more compared to the lower channels). 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 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 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, 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 !

I confirmed there are no splitters used in my setup - we are located at the end of a cul-de-sac and my next door neighbor mentioned that they have been experiencing intermittent outages with their Xfinity TV service (we are internet only). I have NOT made any changes to my internal COAX in years (nor any other network changes) and this problem is recent in past couple of months. Looking at logs from past few days looks like issues start occurring late morning (11am ish) and looking at Event logs (as seen above) issue corrects itself usually within a minute but can occasional take much longer.

Event logs shows Type code 16 errors always on Channel ID: 193 (Not on any other channel) not sure if that means anything.

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 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 !

I think that you can through the Xfinity App if you have it.

Update: Xfinity Tech came out and stated the power levels at street was low and that the loss in signal from the road/drop to our house was more than expected. His recommendation was to replace the underground cable from drop/road to our house as well as have another crew/team address the power levels at road/drop location.

Cable from drop/road to our house was recently replaced - I do NOT know or have insight into what if anything was done to address power levels at street / drop location.

HOWEVER - I am still experiencing internet disruptions and see the following error codes in modem event logs (today). Any suggestions?

Event Log

01/05/2023 15:19 82000500 3 "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 11:40 74010100 6 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 11:39 74010100 6 "CM-STATUS message sent. Event Type Code: 22; Chan ID: 193; 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;"
01/05/2023 11:39 74010100 6 "CM-STATUS message sent. Event Type Code: 5; Chan ID: 33 34 35 36 37 38 39 40 41 42 43 44; 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;"
01/05/2023 11:39 74010100 6 "CM-STATUS message sent. Event Type Code: 4; Chan ID: 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 193; 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;"
01/05/2023 11:39 82000400 3 "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 11:39 74010100 6 "CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 11:39 84020300 5 "MDD message timeout;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 11:16 82000500 3 "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 06:09 74010100 6 "CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 04:01 74010100 6 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:54 74010100 6 "CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:54 85000200 3 "UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:54 67061600 6 "DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:44 85000200 3 "UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:35 74010100 6 "CM-STATUS message sent. Event Type Code: 1; Chan ID: 193; 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;"
01/05/2023 03:34 84020300 5 "MDD message timeout;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 74010100 6 "CM-STATUS message sent. Event Type Code: 21; Chan ID: 193; 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;"
01/05/2023 03:34 85000200 3 "UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 85000200 3 "UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 85000200 3 "UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 84000500 3 "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 67061600 6 "DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:34 2436694066 6 "Honoring MDD; IP provisioning mode = IPv6"
01/05/2023 03:34 85000200 3 "UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:33 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:30 82000400 3 "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:30 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:30 82000400 3 "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:30 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:29 84020300 5 "MDD message timeout;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:29 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:29 84020300 5 "MDD message timeout;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 03:29 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"
01/05/2023 02:29 82000500 3 "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"

Status

Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
20 Locked QAM256 567000000 Hz -4.9 dBmV 38.5 dB 84 216
13 Locked QAM256 525000000 Hz -4.4 dBmV 38.7 dB 1 0
14 Locked QAM256 531000000 Hz -4.5 dBmV 38.8 dB 92 481
15 Locked QAM256 537000000 Hz -4.7 dBmV 38.6 dB 97 477
16 Locked QAM256 543000000 Hz -4.7 dBmV 38.6 dB 87 491
17 Locked QAM256 549000000 Hz -4.7 dBmV 38.5 dB 99 478
18 Locked QAM256 555000000 Hz -4.6 dBmV 38.7 dB 105 472
19 Locked QAM256 561000000 Hz -4.4 dBmV 39.0 dB 96 482
21 Locked QAM256 573000000 Hz -5.1 dBmV 38.4 dB 97 436
22 Locked QAM256 579000000 Hz -5.8 dBmV 38.0 dB 76 457
23 Locked QAM256 585000000 Hz -5.6 dBmV 38.1 dB 91 455
24 Locked QAM256 591000000 Hz -5.9 dBmV 37.9 dB 112 436
25 Locked QAM256 597000000 Hz -5.8 dBmV 37.8 dB 113 506
26 Locked QAM256 603000000 Hz -6.0 dBmV 37.7 dB 103 502
27 Locked QAM256 609000000 Hz -5.8 dBmV 37.9 dB 114 493
28 Locked QAM256 615000000 Hz -5.7 dBmV 37.9 dB 113 499
29 Locked QAM256 621000000 Hz -5.8 dBmV 37.6 dB 93 520
30 Locked QAM256 627000000 Hz -6.0 dBmV 37.6 dB 103 519
31 Locked QAM256 633000000 Hz -6.4 dBmV 37.4 dB 118 509
32 Locked QAM256 639000000 Hz -6.2 dBmV 37.7 dB 170 521
33 Locked QAM256 645000000 Hz -6.6 dBmV 37.3 dB 169 577
34 Locked QAM256 651000000 Hz -6.7 dBmV 37.1 dB 284 1042
35 Locked QAM256 657000000 Hz -7.0 dBmV 36.7 dB 343 1033
36 Locked QAM256 663000000 Hz -7.1 dBmV 36.4 dB 289 1043
37 Locked QAM256 669000000 Hz -7.2 dBmV 36.4 dB 278 1015
38 Locked QAM256 675000000 Hz -7.9 dBmV 35.1 dB 276 1020
39 Locked QAM256 681000000 Hz -7.7 dBmV 36.0 dB 197 1039
40 Locked QAM256 687000000 Hz -7.9 dBmV 36.0 dB 193 1003
41 Locked QAM256 693000000 Hz -7.3 dBmV 36.6 dB 219 1021
42 Locked QAM256 699000000 Hz -7.4 dBmV 36.6 dB 190 905
43 Locked QAM256 705000000 Hz -7.1 dBmV 36.6 dB 174 922
44 Locked QAM256 711000000 Hz -7.2 dBmV 36.4 dB 184 911
193 Locked Other 957000000 Hz -12.6 dBmV 26.0 dB 2363451139 1460806921

Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 17 Locked SC-QAM Upstream 16400000 Hz 6400000 Hz 39.0 dBmV
2 18 Locked SC-QAM Upstream 22800000 Hz 6400000 Hz 40.0 dBmV
3 19 Locked SC-QAM Upstream 29200000 Hz 6400000 Hz 41.0 dBmV
4 20 Locked SC-QAM Upstream 35600000 Hz 6400000 Hz 42.0 dBmV

Current System Time: Thu Jan 5 15:34:17 2023

@EG  - Wanted to see if you could review my current modem signals (to rule in or out connection issues) and provide any suggestions. An Xfinity Line crew made some changes in my neighborhood which improved the signal levels and SNR; however, I am still experiencing some network "hicups" where I will get brief (15 secs to 1 min) drops in connection - network quality. Not sure if it may be an issue my my modem (SB8200) or my Google Wifi Mesh units.  

Note: These brief network disruptions (before the Xfinity Line Crew changes today) was linked to Event Type 16 & 24 errors in my modem event log) - last few hours I have NOT seen those but have had some brief network performance hicups.

Current System Time: Wed Jan 25 16:27:41 2023

@mcavallari 

Sure. There is still a bit of a roll-off of power of the higher frequency channels (+5.5 dB at channel #1 to -1.7 dB at the *Other* / OFDM channel) but 957 MHz is a very high frequency ! But it is very much better ! You are on a 1000 / 1002 MHz plant now. Years ago cable plants only went to 550 MHz and then to 850 MHz.

That said. To narrow things down, see if a computer that is hardwired via an ethernet cable to the main Google mesh router has the same problem. You could even hardwire directly to the 8200 cable modem and see.