Last month, I switched ISPs to Xfinity with an 800Mbps plan, but continue to use the same s33.
I have noticed my download speed will occasionally drops to be around100Mbps, independent of whether I use the 1Gitabit or 2.5Gigabit port. using my ORBI router statistics, I can see the WAN port drops to 100M/Full down from 1000M/Full. To get my speed back, I have to reconnect my patch cable (CAT6) from the modem to the router to the opposite port on the modem (1 vs. 2.5Gigabit). Sometimes I have to reboot the modem as well. Unfortunately, I don’t know exactly when this change happens so I can’t check the event logs at that specific moment. I have seen this with my previous ISP as well, so I don’t think this is specific to the ISP. So what would cause this? How can I resolve?
While investigating this issue, I did look at the event log to see if I can find anything unusual. Two things I have found, but may or may not be related.
(edit: CM-MAC information removed)
- My event log listed a number of incorrect initialized date values (“31/12/1969”). I tried to “Restore Factory Defaults”, but it still shows the initialized dates. Could this be timing/sync problem causing this drop? Or can this be safely ignored?
31/12/1969
19:00:353 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:353 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 28/12/2022
15:03:293 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:153 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:203 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; 31/12/1969
19:00:223 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:223 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:223 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:243 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:353 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:353 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:353 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 28/12/2022
16:06:443 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:153 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:193 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; 31/12/1969
19:00:203 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:203 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:203 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:223 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:333 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:333 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:333 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 28/12/2022
16:23:553 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:153 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:193 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; 31/12/1969
19:00:203 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:203 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:203 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:223 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:333 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:333 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:333 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 28/12/2022
16:33:463 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:153 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:193 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; 31/12/1969
19:00:213 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:213 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:213 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:243 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:363 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:363 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:363 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 28/12/2022
17:00:453 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:163 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:213 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; 31/12/1969
19:00:233 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:233 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:233 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:243 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:363 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:363 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:363 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 28/12/2022
17:05:193 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:153 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:193 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; 31/12/1969
19:00:213 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:213 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:213 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:233 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:353 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:353 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:353 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 29/12/2022
15:21:533 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:163 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:193 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; 31/12/1969
19:00:213 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:213 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:213 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:233 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:353 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:353 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:353 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 29/12/2022
15:25:243 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 29/12/2022
15:45:133 Failed LAN WebGUI login attempt from ***.***.***.*** on 22/12/29 at 3:45 PM. 29/12/2022
15:46:163 Successful LAN WebGUI login from ***.***.***.*** on 22/12/29 at 3:46 PM. 31/12/1969
19:00:153 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:193 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; 31/12/1969
19:00:203 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:203 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:203 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:223 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:343 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:343 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:343 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 29/12/2022
16:15:013 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 29/12/2022
16:16:023 Successful LAN WebGUI login from ***.***.***.*** on 22/12/29 at 4:16 PM. 31/12/1969
19:00:153 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz. 31/12/1969
19:00:203 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; 31/12/1969
19:00:223 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz. 31/12/1969
19:00:223 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz. 31/12/1969
19:00:223 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz. 31/12/1969
19:00:243 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 31/12/1969
19:00:286 Honoring MDD; IP provisioning mode = IPv6 31/12/1969
19:00:363 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz. 31/12/1969
19:00:363 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz. 31/12/1969
19:00:363 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz. 29/12/2022
16:19:366 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; 29/12/2022
16:19:433 UCD invalid or channel unusable;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1; 29/12/2022
16:20:333 Successful LAN WebGUI login from ***.***.***.*** on 22/12/29 at 4:20 PM. 29/12/2022
16:21:273 Successful LAN WebGUI login from ***.***.***.*** on 22/12/29 at 4:21 PM.
- Comparing the Upstream powers levels from Arris vs. Xfinity: General FAQs: S33: Cable Signal Levels (force.com) vs arris s33 frequent disconnect | Xfinity Community Forum, the Upstream Power for a 4 SC-QAM channel should be in the range of 45 - 51, however, Xfinity states the Upstream power should be between 35 and 51. Mine is currently showing: (does this matter?)
-
Channel ID Lock Status US Channel Type Frequency Width Power 1 Locked SC-QAM 16400000 Hz 6400000 41.3 dBmV 2 Locked SC-QAM 22800000 Hz 6400000 41.5 dBmV 3 Locked SC-QAM 29200000 Hz 6400000 42.0 dBmV 4 Locked SC-QAM 35600000 Hz 6400000 42.8 dBmV
Here is some more information about my S33.
Hardware Version | V1.0 |
Software Version | TB01.03.001.10_012022_212.S3 |
Appreciate the help. --Tom