I recently purchased a Netgear CM1000 for use on Comcast and several times a day the internet just stops working despite all lights still showing green. When this happens I can't even log into the web management app. Turning the modem off and back on removes the problem, but this is really annoying to have to do multiple times a day! Any advice is welcomed. Here are some pertinent pieces of information: Hardware Version2.02 Firmware VersionV2.01.14 Acquire Downstream Channel639000000 HzLockedConnectivity StateOKOperationalBoot StateOKOperationalSecurityEnableBPI+IP Provisioning ModeHonor MDDIPv6 only Downstream Bonded ChannelsChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectablesUncorrectables1LockedQAM25617639000000 Hz-1.7 dBmV39.1 dB102LockedQAM2561543000000 Hz-1.3 dBmV40.1 dB003LockedQAM2562549000000 Hz-1.2 dBmV40.1 dB204LockedQAM2563555000000 Hz-1.3 dBmV40.0 dB105LockedQAM2564561000000 Hz-1.4 dBmV39.9 dB206LockedQAM2565567000000 Hz-1.3 dBmV40.0 dB007LockedQAM2566573000000 Hz-1.5 dBmV39.9 dB308LockedQAM2567579000000 Hz-1.4 dBmV39.7 dB209LockedQAM2568585000000 Hz-1.5 dBmV39.7 dB2010LockedQAM2569591000000 Hz-1.5 dBmV39.7 dB4011LockedQAM25610597000000 Hz-1.7 dBmV39.6 dB7012LockedQAM25611603000000 Hz-2.0 dBmV39.3 dB3013LockedQAM25612609000000 Hz-2.5 dBmV39.3 dB5014LockedQAM25613615000000 Hz-2.0 dBmV39.3 dB6015LockedQAM25614621000000 Hz-1.7 dBmV39.3 dB4016LockedQAM25615627000000 Hz-1.7 dBmV39.2 dB2017LockedQAM25616633000000 Hz-1.7 dBmV39.3 dB1018LockedQAM25618645000000 Hz-1.8 dBmV39.3 dB2019LockedQAM25619651000000 Hz-1.7 dBmV39.1 dB3020LockedQAM25620657000000 Hz-1.7 dBmV39.2 dB3021LockedQAM25621663000000 Hz-1.6 dBmV39.1 dB3022LockedQAM25622669000000 Hz-1.6 dBmV39.1 dB1023LockedQAM25623675000000 Hz-1.5 dBmV39.1 dB0024LockedQAM25624681000000 Hz-1.5 dBmV39.0 dB00... Upstream Bonded ChannelsChannelLock StatusUS Channel TypeChannel IDSymbol RateFrequencyPower1LockedATDMA15120 Ksym/sec30100000 Hz45.5 dBmV2LockedATDMA25120 Ksym/sec36500000 Hz45.5 dBmV3LockedATDMA35120 Ksym/sec17300000 Hz43.5 dBmV4LockedATDMA45120 Ksym/sec23700000 Hz45.5 dBmV... TimePriorityDescription2017-01-22, 21:03:53Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:03:58Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:04:05Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:04:49Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:04:49Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:05:09Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:05:10Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:05:28Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:05:29Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-22, 21:05:48Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 19:26:40Critical (3)No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:01:18Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:01:21Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:01:27Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:02:09Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:02:09Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:02:29Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:02:30Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:02:49Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:02:50Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 21:03:09Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 22:53:14Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:00:30Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:00:35Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:00:41Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:01:11Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:01:12Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:01:32Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:01:32Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:01:53Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:01:54Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;2017-01-24, 23:02:12Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;Time Not EstablishedNotice (6)Honoring MDD; IP provisioning mode = IPv6 This event log comes shortly after I had to restart my modem for the second time in the last 2 hours!

Interesting, the overall problem was solved for me and several neighbors. Cox replaced a mini-amplifier in the box at the street. However, I found the item that had the largest impact to overall network stability was unplugging our Ac1200's extenders. interestingly, we each had one on our individual networks and removing them resolved the overall issues.

Forum Discussion

bcassell

Aspirant

Jan 26, 2017

Solved

CM1000 requiring rebooting several times a day (Comcast)

I recently purchased a Netgear CM1000 for use on Comcast and several times a day the internet just stops working despite all lights still showing green. When this happens I can't even log into the web management app. Turning the modem off and back on removes the problem, but this is really annoying to have to do multiple times a day! Any advice is welcomed. Here are some pertinent pieces of information:

Hardware Version	2.02

Firmware Version	V2.01.14

Acquire Downstream Channel	639000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv6 only

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectables
1	Locked	QAM256	17	639000000 Hz	-1.7 dBmV	39.1 dB	1	0
2	Locked	QAM256	1	543000000 Hz	-1.3 dBmV	40.1 dB	0	0
3	Locked	QAM256	2	549000000 Hz	-1.2 dBmV	40.1 dB	2	0
4	Locked	QAM256	3	555000000 Hz	-1.3 dBmV	40.0 dB	1	0
5	Locked	QAM256	4	561000000 Hz	-1.4 dBmV	39.9 dB	2	0
6	Locked	QAM256	5	567000000 Hz	-1.3 dBmV	40.0 dB	0	0
7	Locked	QAM256	6	573000000 Hz	-1.5 dBmV	39.9 dB	3	0
8	Locked	QAM256	7	579000000 Hz	-1.4 dBmV	39.7 dB	2	0
9	Locked	QAM256	8	585000000 Hz	-1.5 dBmV	39.7 dB	2	0
10	Locked	QAM256	9	591000000 Hz	-1.5 dBmV	39.7 dB	4	0
11	Locked	QAM256	10	597000000 Hz	-1.7 dBmV	39.6 dB	7	0
12	Locked	QAM256	11	603000000 Hz	-2.0 dBmV	39.3 dB	3	0
13	Locked	QAM256	12	609000000 Hz	-2.5 dBmV	39.3 dB	5	0
14	Locked	QAM256	13	615000000 Hz	-2.0 dBmV	39.3 dB	6	0
15	Locked	QAM256	14	621000000 Hz	-1.7 dBmV	39.3 dB	4	0
16	Locked	QAM256	15	627000000 Hz	-1.7 dBmV	39.2 dB	2	0
17	Locked	QAM256	16	633000000 Hz	-1.7 dBmV	39.3 dB	1	0
18	Locked	QAM256	18	645000000 Hz	-1.8 dBmV	39.3 dB	2	0
19	Locked	QAM256	19	651000000 Hz	-1.7 dBmV	39.1 dB	3	0
20	Locked	QAM256	20	657000000 Hz	-1.7 dBmV	39.2 dB	3	0
21	Locked	QAM256	21	663000000 Hz	-1.6 dBmV	39.1 dB	3	0
22	Locked	QAM256	22	669000000 Hz	-1.6 dBmV	39.1 dB	1	0
23	Locked	QAM256	23	675000000 Hz	-1.5 dBmV	39.1 dB	0	0
24	Locked	QAM256	24	681000000 Hz	-1.5 dBmV	39.0 dB	0	0
...

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	1	5120 Ksym/sec	30100000 Hz	45.5 dBmV
2	Locked	ATDMA	2	5120 Ksym/sec	36500000 Hz	45.5 dBmV
3	Locked	ATDMA	3	5120 Ksym/sec	17300000 Hz	43.5 dBmV
4	Locked	ATDMA	4	5120 Ksym/sec	23700000 Hz	45.5 dBmV
...

Time	Priority	Description
2017-01-22, 21:03:53	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:03:58	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:04:05	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:04:49	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:04:49	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:05:09	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:05:10	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:05:28	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:05:29	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-22, 21:05:48	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 19:26:40	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:01:18	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:01:21	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:01:27	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:02:09	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:02:09	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:02:29	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:02:30	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:02:49	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:02:50	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 21:03:09	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 22:53:14	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:00:30	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:00:35	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:00:41	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:01:11	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:01:12	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:01:32	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:01:32	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:01:53	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:01:54	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
2017-01-24, 23:02:12	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:1d:45:70:69:60;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=a0:04:60:fc:8d:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6

This event log comes shortly after I had to restart my modem for the second time in the last 2 hours!

CM1000

Troubleshooting

jimradzicki
Oct 17, 2017
Interesting, the overall problem was solved for me and several neighbors. Cox replaced a mini-amplifier in the box at the street. However, I found the item that had the largest impact to overall network stability was unplugging our Ac1200's extenders. interestingly, we each had one on our individual networks and removing them resolved the overall issues.

66 Replies

DarrenM
Sr. NETGEAR Moderator
Jan 27, 2017
Hello bcassell

I see alot of T3 and T4 timeouts this usually is a issue with the connection to your home you may need to have your ISP tech come out and check the lines.

https://volpefirm.com/docsis_timout_descriptions/

DarrenM
vkdelta
NETGEAR Employee Retired
Feb 04, 2017
Hi,

NTGR observed this issue with specific users and working on FW fix and is currently under validation.

we should have an update for you by 2/7. Hit us back and we will let you.
BMWDude49120
Tutor
Feb 04, 2017
I am having the exact same issues with my CM1000, as well as slower download and upload speeds than my previous Arris SB6190. I sent an email to netgearteam@netgear.com and they replied they are going to work with Comcast to pull logs, etc., on my modem to see if they can figure out what is going on. The reply here from Netgear is also promising. I suspected these issues were due to a firmware bug, so am now hopeful Netgear will have a fix soon. I am subscribing to this thread to watch for any updates.
bcassell
Aspirant
Feb 04, 2017
Awesome to hear.
- Shade00
  Guide
  Feb 05, 2017
  I would like to chime in and add that I am also experiencing this exact same issue with the same log entries. I had to power cycle today to get my internet access back. I am hopeful we will get a firmware update soon as I would prefer not to have to return the modem.
  - vkdelta
    NETGEAR Employee Retired
    Feb 06, 2017
    thank for your patience. Will let you know our validation results soon.
Prcheek
Aspirant
Feb 07, 2017
Any update?

I'm experiencing the same issues stated above PLUS if I change the modem login password, I can no longer hardwire my laptop to the cm1000 for speed test purposes.
Sirghost
Aspirant
Feb 07, 2017
Also desperate here for an update on this as I am having the exact same issues and almost ready to return the modem to the store unless something is very very close to being done about this.
- EnduroDriver
  Tutor
  Feb 07, 2017
  Also having the same problem, works great when it works but I'm having to reset it two and three times a day. Unlike the original poster I don't have all green lights. Mine drops the UPSTREAM and INTERNET lights and a blinking DOWNSTREAM light likes it's searching for a signal. A quick power cycle and it's back up and running so I'm sure it's not a problem at the cable company. I also recently had a service call from Comcast that checked out signal strength and noise and they gave me a clean bill of health. Rather disappointed that I replaced a rock solid SB6141 with this.
CowBoy_Tech
Tutor
Feb 08, 2017
I am having the same problems and have the same type of logs. Comcast has been here several times in the last 2 weeks and replaced cable lines from the pole to the modem also installed a powered amplifier and am now on my second test modem. They checked the nodes in my area and found a large amount of noise. It has been escalated up to a regional customer service manager and no one even seems to know that this is a known issue with the CM1000.
vkdelta
NETGEAR Employee Retired
Feb 09, 2017
FW is certified by the ISP. Just waiting for deployment. Will confirm soon.
- lsg
  Aspirant
  Feb 09, 2017
  Is FW coming to Cox as well? I'm having similar issues on Cox.
  - Shade00
    Guide
    Feb 09, 2017
    That's great news, vkdelta. Please keep us updated.

vkdelta

NETGEAR Employee Retired

Feb 11, 2017

Comcast should happen early next week.

COX will directly go to .15 as well. (no need to go .14). no ETA but should happen soon.

Shade00

Guide

Feb 13, 2017

Two more dropouts today, one yesterday. I really hope early next week means tomorrow. This is beyond frustrating.

CowBoy_Tech

Tutor

Feb 13, 2017

Try having this many disconnects in the last 5 hors.....

Time	Priority	Description
2017-02-12, 15:02:52	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:02:58	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:03:43	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:03:50	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:04:32	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:04:38	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:05:22	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:05:27	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:06:11	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:06:15	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:06:57	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:07:02	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:07:45	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:07:50	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:08:32	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:09:32	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:11:11	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:11:18	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:12:04	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:12:10	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:12:55	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:13:00	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
2017-02-12, 15:13:42	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=b0:7f:b9:66:d6:38;CMTS-MAC=00:01:5c:7f:a0:61;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6

Help

Center

Hydro130
Luminary
Feb 13, 2017
Dropouts from CM1000 are now increasing to several times a day for me - this is now well past being an annoyance...

Oh mighty Netgear and Comcast gods - please release v .15 firmware asap!!!
- vkdelta
  NETGEAR Employee Retired
  Feb 13, 2017
  One last step to go...almost getting there. I can understand your situation..
  Just waiting for ISP to deploy new config files.

BMWDude49120
Tutor
Feb 15, 2017
Well, I received the .15 firmware last night and it has not brought my DL and UL speeds back to the sames speeds I have gotten with every single other modem I have ever owned, so I have decided I will be returning the CM1000 to Amazon today. I am not going to keep a brand new $180 32x4 modem that is outperformed by a 4 year old Arris SB6141 that only has 8x4 channels. Sorry, Netgear. I gave you a chance, but back to Arris I go. Looks like I will order the new SB8200 and see how that goes.
- CowBoy_Tech
  Tutor
  Feb 15, 2017
  I received it also between 2AM and 7AM this morning and things seem to have improved here. Speeds are good and Only time will tell!
  - CowBoy_Tech
    Tutor
    Feb 16, 2017
    Well 11 hours and no problems yet....