Progressively worse connection - any suggestions?

Question

For over 3 months my connectivity has progressively gotten worse, it started with sporadict drops and now it's multiple times a day. I've tried; replacing my modem, replacing my router and having an Comcast technician test to my wall outlet.

It's gotten to a point that we are struggling to keep a connection during work team meetings.

Does anyone have any ideas on how I can get this resolved?

There are multiple critical enteries in my log :

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

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Frequency start Value

This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.

Starting Frequency

Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	525000000 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	QAM256	20	525000000 Hz	1.8 dBmV	42.3 dB	5	0
2	Locked	QAM256	4	411000000 Hz	-0.1 dBmV	41.9 dB	0	0
3	Locked	QAM256	5	417000000 Hz	0.1 dBmV	42 dB	0	0
4	Locked	QAM256	6	435000000 Hz	0.3 dBmV	42 dB	0	0
5	Locked	QAM256	7	441000000 Hz	0.1 dBmV	41.9 dB	0	0
6	Locked	QAM256	8	453000000 Hz	0.7 dBmV	42.3 dB	0	0
7	Locked	QAM256	9	459000000 Hz	0.8 dBmV	42.3 dB	0	0
8	Locked	QAM256	10	465000000 Hz	0.8 dBmV	42.3 dB	0	0
9	Locked	QAM256	11	471000000 Hz	0.8 dBmV	42.2 dB	0	0
10	Locked	QAM256	12	477000000 Hz	0.8 dBmV	42.1 dB	0	0
11	Locked	QAM256	13	483000000 Hz	1 dBmV	42.2 dB	5	0
12	Locked	QAM256	14	489000000 Hz	1.3 dBmV	42.4 dB	1	0
13	Locked	QAM256	15	495000000 Hz	1.4 dBmV	42.3 dB	0	0
14	Locked	QAM256	16	501000000 Hz	1.5 dBmV	42.3 dB	2	0
15	Locked	QAM256	17	507000000 Hz	1.6 dBmV	42.3 dB	1	0
16	Locked	QAM256	18	513000000 Hz	1.6 dBmV	42.3 dB	9	0
17	Locked	QAM256	19	519000000 Hz	1.8 dBmV	42.3 dB	5	0
18	Locked	QAM256	21	531000000 Hz	1.8 dBmV	42.2 dB	6	0
19	Locked	QAM256	22	537000000 Hz	1.8 dBmV	42.2 dB	6	0
20	Locked	QAM256	23	543000000 Hz	1.9 dBmV	42.3 dB	4	0
21	Locked	QAM256	24	549000000 Hz	1.9 dBmV	42.3 dB	6	0
22	Locked	QAM256	25	555000000 Hz	2.1 dBmV	42.3 dB	4	0
23	Locked	QAM256	26	561000000 Hz	2.2 dBmV	42.3 dB	7	0
24	Locked	QAM256	27	567000000 Hz	2.1 dBmV	42.3 dB	5	0
25	Locked	QAM256	28	573000000 Hz	2 dBmV	42.2 dB	6	0
26	Locked	QAM256	29	579000000 Hz	1.8 dBmV	42 dB	6	0
27	Locked	QAM256	30	585000000 Hz	1.7 dBmV	41.9 dB	10	0
28	Locked	QAM256	31	591000000 Hz	1.6 dBmV	41.8 dB	5	0
29	Locked	QAM256	32	597000000 Hz	1.7 dBmV	41.7 dB	5	0
30	Locked	QAM256	33	603000000 Hz	1.6 dBmV	42 dB	7	0
31	Locked	QAM256	34	609000000 Hz	1.3 dBmV	41.9 dB	5	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	2	5120 Ksym/sec	22800000 Hz	50.5 dBmV
2	Locked	ATDMA	3	5120 Ksym/sec	29200000 Hz	49.3 dBmV
3	Locked	ATDMA	4	5120 Ksym/sec	35600000 Hz	47.8 dBmV
4	Locked	ATDMA	5	1280 Ksym/sec	40400000 Hz	45 dBmV
5	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV

Downstream OFDM Channels

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	48	722000000 Hz	3.5 dBmV	41.7 dB	1228 ~ 2867	531412734	726	0
2	Not Locked	0	0	0 Hz	0 dBmV	0.0 dB	0 ~ 4095	0	0	0

Upstream OFDMA Channels

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

Extended Upstream Transmit PowerEnable Extended Upstream Transmit Power

Current System Time:Mon Oct 12 14:20:55 2020System Up Time:12:31:13

EG · Answer

The upstream power is high and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In a self troubleshooting 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 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

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 get the techs re-involved until it is fixed properly. Good luck !

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EG · Answer

It's too high. 'Attenuators' can't lower the upstream power, they make it higher ! Attenuators lower the downstream power. Is that what you meant to say ?

BELL5 · Answer

EG, thank you for the reply and the troubleshooting steps. Last week the Comcast technician did place an attenuator to lower the upstream power.

BELL5 · Answer

Now I'm second guessing the conversation. I recall he said something was too high and that he placed something on the coax to correct it.

EG · Answer

Try removing it and repost the stats.

BELL5 · Answer

I couldn't find the cable that the tech had placed the attenuator on, there are half a dozen coax cables in my attic for some reason!

Like clockwork my connection went down again. It seems to happen around 1pm - 2pm CST everyday and then again later in the evening.

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Frequency start Value

This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.

Starting Frequency

Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	525000000 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	QAM256	20	525000000 Hz	1.8 dBmV	42.5 dB	1014	833
2	Locked	QAM256	4	411000000 Hz	-0.1 dBmV	42.1 dB	2284	859
3	Locked	QAM256	5	417000000 Hz	0.1 dBmV	42.2 dB	2297	899
4	Locked	QAM256	6	435000000 Hz	0.3 dBmV	42.2 dB	1981	840
5	Locked	QAM256	7	441000000 Hz	0 dBmV	42.1 dB	1748	883
6	Locked	QAM256	8	453000000 Hz	0.6 dBmV	42.5 dB	1697	887
7	Locked	QAM256	9	459000000 Hz	0.7 dBmV	42.5 dB	2042	853
8	Locked	QAM256	10	465000000 Hz	0.7 dBmV	42.4 dB	1536	910
9	Locked	QAM256	11	471000000 Hz	0.7 dBmV	42.4 dB	1571	929
10	Locked	QAM256	12	477000000 Hz	0.7 dBmV	42.3 dB	1524	877
11	Locked	QAM256	13	483000000 Hz	0.8 dBmV	42.3 dB	1654	835
12	Locked	QAM256	14	489000000 Hz	1.2 dBmV	42.5 dB	1477	885
13	Locked	QAM256	15	495000000 Hz	1.2 dBmV	42.5 dB	1380	857
14	Locked	QAM256	16	501000000 Hz	1.4 dBmV	42.5 dB	1214	867
15	Locked	QAM256	17	507000000 Hz	1.5 dBmV	42.5 dB	934	817
16	Locked	QAM256	18	513000000 Hz	1.5 dBmV	42.5 dB	1211	848
17	Locked	QAM256	19	519000000 Hz	1.7 dBmV	42.5 dB	1225	845
18	Locked	QAM256	21	531000000 Hz	1.8 dBmV	42.4 dB	902	814
19	Locked	QAM256	22	537000000 Hz	1.9 dBmV	42.4 dB	771	799
20	Locked	QAM256	23	543000000 Hz	2 dBmV	42.5 dB	725	753
21	Locked	QAM256	24	549000000 Hz	2.1 dBmV	42.5 dB	733	785
22	Locked	QAM256	25	555000000 Hz	2.2 dBmV	42.5 dB	637	729
23	Locked	QAM256	26	561000000 Hz	2.3 dBmV	42.5 dB	674	731
24	Locked	QAM256	27	567000000 Hz	2.3 dBmV	42.5 dB	588	761
25	Locked	QAM256	28	573000000 Hz	2.2 dBmV	42.4 dB	654	798
26	Locked	QAM256	29	579000000 Hz	2 dBmV	42.2 dB	845	738
27	Locked	QAM256	30	585000000 Hz	1.9 dBmV	42.1 dB	923	722
28	Locked	QAM256	31	591000000 Hz	1.8 dBmV	42 dB	756	786
29	Locked	QAM256	32	597000000 Hz	1.9 dBmV	41.9 dB	744	750
30	Locked	QAM256	33	603000000 Hz	1.8 dBmV	42.2 dB	772	804
31	Locked	QAM256	34	609000000 Hz	1.4 dBmV	42.1 dB	1002	822
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	2	5120 Ksym/sec	22800000 Hz	50.3 dBmV
2	Locked	ATDMA	3	5120 Ksym/sec	29200000 Hz	49.3 dBmV
3	Locked	ATDMA	4	5120 Ksym/sec	35600000 Hz	48 dBmV
4	Locked	ATDMA	5	1280 Ksym/sec	40400000 Hz	45 dBmV
5	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV

Downstream OFDM Channels

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	48	722000000 Hz	3.5 dBmV	41.7 dB	1228 ~ 2867	1904098495	10899054	396
2	Not Locked	0	0	0 Hz	0 dBmV	0.0 dB	0 ~ 4095	0	0	0

Upstream OFDMA Channels

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

Extended Upstream Transmit PowerEnable Extended Upstream Transmit Power

Current System Time:Tue Oct 13 12:41:48 2020System Up Time:1 day 10:52:06

EG · Answer

It's still too high. Perhaps it would be best to get another tech out to investigate / correct the problem. Good luck with it !

ComcastAmira · Answer

Hello @BELL5, thanks for reaching out to us on our Forums page. We appreciate you being a customer with us, and I apologize for the connection issues you have recently been experiencing. We definitely understand how important it is to have a steady and consistent connection. I can imagine how inconvenient and frustrating these connection issues must be. We would love to help! I see you have already sent me a private message and I will respond promptly.

Your Home Network

BELL5

Progressively worse connection - any suggestions?

Responses

EG

EG

BELL5

BELL5

EG

BELL5

EG

ComcastAmira

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