Hi,

I have a persistent intermittent connection issue going on for ~1yr, and lived with it until I started wfh. My connection normally works fine, then drops for 45-60seconds, 4-20 times a day (I have a ping log tracking outages).

Things I've tried so far:

1. I have a modem, router & 24 port switch normally connected. I experience the same problem whether I'm:

a) Using wifi or wired

b) Using latop, desktop, phone or ipad

c) Doesn't matter how often I reboot

d) Have tried taking my cable modem outside connected directly to cable drop, hardwired into my laptop - same issues (i.e. bypassing all itnernal wiring, routers, wifi and switches)

e ) Replced cable modem tried Arris, and two different Netgears - currenlty using CM400

Called comcast:

2. Replaced cable drop to my house

3. Reterminated by internal cable connections

4. Retested all the wiring into my modem

5. On all occasions I get the standard "everything looks good, great SNR and power levels

6. Today I was told "not our problem, everything is fine, you need to call NetGear"

Any help or suggestions would be appreciated, below are the modem stats and event log

Cable Connection

<tabindex=-1>Startup Procedure</tabindex=-1>

Procedure	Status	Comment
Acquire Downstream Channel	687000000 Hz	Locked
Connectivity State	Ok	Operational
Boot State	Ok	Operational
Security	Enabled	BPI+
IP Provisioning Mode	Honor MDD	honorMdd(4)

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	UnCorrectables
1	Locked	QAM 256	40	645000000 Hz	5.1 dBmV	37.0 dB	7316	613
2	Locked	QAM 256	41	651000000 Hz	4.9 dBmV	37.3 dB	8618	530
3	Locked	QAM 256	42	657000000 Hz	4.8 dBmV	37.3 dB	9243	477
4	Locked	QAM 256	43	663000000 Hz	4.6 dBmV	37.3 dB	7454	551
5	Locked	QAM 256	44	669000000 Hz	4.5 dBmV	37.6 dB	4396	705
6	Locked	QAM 256	45	675000000 Hz	4.4 dBmV	37.3 dB	4085	659
7	Locked	QAM 256	46	681000000 Hz	4.4 dBmV	37.3 dB	4351	628
8	Locked	QAM 256	47	687000000 Hz	4.4 dBmV	37.3 dB	4155	1532

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	21	5120 Ksym/sec	19300000 Hz	41.8 dBmV
2	Locked	ATDMA	22	5120 Ksym/sec	25700000 Hz	41.5 dBmV
3	Locked	ATDMA	23	5120 Ksym/sec	32300000 Hz	42.3 dBmV
4	Locked	ATDMA	24	5120 Ksym/sec	38700000 Hz	42.8 dBmV

Current System Time: Tue Mar 31 20:20:07 2020

System Up Time: 07:25:01

Event log

Time	Priority	Description
Dec 18 02:51:12 2019	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
Dec 18 02:51:33 2019	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Dec 18 04:27:07 2019	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Dec 18 04:27:12 2019	Warning (5)	Lost MDD Timeout
Dec 18 04:29:30 2019	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
Dec 18 04:32:33 2019	Critical (3)	No Ranging Response received - T3 time-out
Dec 18 04:32:43 2019	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Dec 18 04:32:45 2019	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out
Jan 2 15:32:22 2020	Critical (3)	No Ranging Response received - T3 time-out
Jan 23 20:50:46 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Feb 2 17:26:03 2020	Critical (3)	No Ranging Response received - T3 time-out
Feb 19 01:48:32 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Feb 19 01:48:33 2020	Critical (3)	No Ranging Response received - T3 time-out
Feb 19 01:50:34 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Feb 19 01:50:41 2020	Critical (3)	No Ranging Response received - T3 time-out
Feb 19 03:56:59 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Feb 19 03:57:06 2020	Critical (3)	No Ranging Response received - T3 time-out
Feb 19 04:03:43 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Feb 19 04:03:48 2020	Critical (3)	No Ranging Response received - T3 time-out
Mar 12 15:50:34 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Mar 15 10:44:35 2020	Critical (3)	No Ranging Response received - T3 time-out
Mar 22 06:13:10 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Mar 22 06:17:58 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Mar 22 06:20:04 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Mar 22 16:29:00 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Mar 22 16:31:56 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Mar 29 12:11:46 2020	Warning (5)	TEK Invalid - Invalid Key Sequence Number
Mar 30 10:04:09 2020	Warning (5)	Lost MDD Timeout
Mar 30 10:05:54 2020	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync
Mar 30 10:05:59 2020	Warning (5)	Lost MDD Timeout
Mar 30 10:08:19 2020	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
Mar 30 10:09:28 2020	Warning (5)	Lost MDD Timeout
Mar 30 10:09:45 2020	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
Mar 30 10:10:27 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Mar 30 10:10:28 2020	Warning (5)	RCS Partial Service
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Mar 30 12:59:06 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Mar 31 12:55:47 2020	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1

Forum Discussion

CM400 modem - Intermittent connection problem