Intermittent Internet Disconnects - Xfinity Help and Support Forums

js1933 · ‎01-22-2021

Hello! I have an issue where my Cable Modem repeatedly loses connection. This happens many times throughout the day. Looking at the Xfinity App on my iPhone, it will repeatedly say "NETGEAR CM1000 disconnected" and show me offline, only for a moment, then it will reconnect.

The wiring into my house is 1 coax feed into the basement, which is connected to a Male-Male Coax Connector, and is then connected to the coax cable which goes directly upstairs and plugs into my Cable Modem, a new Netgear CM1000v2. From there, it's connected to a new router, TP LINK A10. All coax runs in the house were done by comcast. I experienced this behavior on my old equipment, so I bought the new modem and router, but that has not changed the behavior. Signal levels and event log are below. Comcast came out once, and said the levels at the street looked good. I didn't let them inside because this was during the worst of the COVID-19 outbreak.

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

Procedure	Status	Comment
Acquire Downstream Channel	519000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv6 only

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	13	519000000 Hz	7.2 dBmV	42.1 dB	750135224	0	0
2	Locked	QAM256	10	501000000 Hz	7.2 dBmV	42.0 dB	750139864	0	0
3	Locked	QAM256	11	507000000 Hz	7.3 dBmV	42.0 dB	750148716	0	0
4	Locked	QAM256	12	513000000 Hz	7.5 dBmV	42.2 dB	750152852	0	0
5	Locked	QAM256	14	525000000 Hz	7.4 dBmV	42.2 dB	750156590	0	0
6	Locked	QAM256	15	531000000 Hz	7.0 dBmV	42.1 dB	750160367	0	0
7	Locked	QAM256	16	537000000 Hz	7.1 dBmV	42.1 dB	750164072	0	0
8	Locked	QAM256	17	543000000 Hz	6.9 dBmV	42.0 dB	750167974	0	0
9	Locked	QAM256	18	549000000 Hz	6.7 dBmV	41.8 dB	750173395	0	0
10	Locked	QAM256	19	561000000 Hz	6.6 dBmV	41.9 dB	750176869	0	0
11	Locked	QAM256	20	567000000 Hz	6.7 dBmV	41.9 dB	750181425	0	0
12	Locked	QAM256	21	573000000 Hz	6.4 dBmV	41.7 dB	750184383	0	0
13	Locked	QAM256	22	579000000 Hz	6.8 dBmV	42.0 dB	750171177	0	0
14	Locked	QAM256	23	585000000 Hz	6.5 dBmV	41.7 dB	750171338	0	0
15	Locked	QAM256	24	591000000 Hz	6.6 dBmV	41.9 dB	750172816	0	0
16	Locked	QAM256	26	597000000 Hz	6.8 dBmV	41.9 dB	750165162	0	0
17	Locked	QAM256	27	603000000 Hz	6.6 dBmV	41.8 dB	750174289	0	0
18	Locked	QAM256	28	609000000 Hz	6.5 dBmV	41.9 dB	750177848	0	0
19	Locked	QAM256	29	615000000 Hz	6.3 dBmV	41.5 dB	750182185	0	0
20	Locked	QAM256	30	621000000 Hz	6.3 dBmV	41.7 dB	750185338	0	0
21	Locked	QAM256	31	627000000 Hz	6.2 dBmV	41.6 dB	750189870	0	0
22	Locked	QAM256	32	633000000 Hz	6.2 dBmV	41.6 dB	750193548	0	0
23	Locked	QAM256	33	639000000 Hz	6.0 dBmV	41.5 dB	750197759	0	0
24	Locked	QAM256	34	645000000 Hz	6.0 dBmV	41.5 dB	750201280	0	0
25	Locked	QAM256	35	651000000 Hz	6.3 dBmV	41.6 dB	750205258	0	0
26	Locked	QAM256	36	657000000 Hz	6.0 dBmV	41.5 dB	750208615	0	0
27	Locked	QAM256	37	663000000 Hz	6.3 dBmV	41.6 dB	750212685	0	0
28	Locked	QAM256	38	669000000 Hz	6.1 dBmV	41.4 dB	750216232	0	0
29	Locked	QAM256	39	675000000 Hz	6.2 dBmV	41.1 dB	750218658	0	0
30	Locked	QAM256	40	681000000 Hz	5.9 dBmV	41.3 dB	750221731	0	0
31	Locked	QAM256	41	687000000 Hz	6.0 dBmV	41.2 dB	750224507	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	29	36500000 Hz	41.3 dBmV
2	Locked	ATDMA	30	30100000 Hz	42.3 dBmV
3	Locked	ATDMA	31	23700000 Hz	41.8 dBmV
4	Locked	ATDMA	32	17300000 Hz	42.3 dBmV
5	Not Locked	Unknown	0	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Hz	0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power	SNR / MER	Active Subcarrier Number Range	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	0, 1, 2, 3	25	693000000 Hz	6.3 dBmV	39.8 dB	1108 ~ 2987	198123354	161469780	520
2	Not Locked	0	0	0 Hz	11.0 dBmV	0.0 dB	0 ~ 4095	0	0	0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power
1	Not Locked	Unknown	0	0 Hz	0 dBmV
2	Not Locked	Unknown	0	0 Hz	0 dBmV

Current System Time: Sat Jan 23 15:23:40 2021

System Up Time: 4:36:04

2021-01-23, 11:24:40	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;CM-QOS=1.1;CM-VER=3.1;
2021-01-23, 10:48:30	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;CM-QOS=1.1;CM-VER=3.1;
2021-01-23, 10:48:30	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;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=9c:c9:eb:87:75:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2021-01-23, 10:40:05	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;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=9c:c9:eb:87:75:00;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=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;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=9c:c9:eb:87:75:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2021-01-23, 01:18:54	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:87:75:00;CMTS-MAC=00:01:5c:62:8a:55;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=9c:c9:eb:87:75:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;