Frequent Internet outages

[bshyamkumar]

I live in the 98075 zipcode. I typically have at least a couple of internet outages per week each lasting more than a couple of hours. The TV works fine, but internet goes down and comes back after a few hours. On 9/4, the outage lasted almost 12 hours. This is my device status:

Hardware Information

System:	ARRIS DOCSIS 3.0 Touchstone WideBand Cable Modem HW_REV: 1 VENDOR: Arris Interactive, L.L.C. BOOTR: 1.2.1.62 SW_REV: 9.1.103M2AS.CT MODEL: CM820A
Serial Number:	E4UBRL6AM100136
Options:

 Firmware Build and Revisions

Firmware Name:	TS0901103M2AS_112019_WBM760_CM820_CT
Firmware Build Time:	Wed Nov 20 14:18:48 EST 2019

Downstream

	DCID	Freq	Power	SNR	Modulation	Octets	Correcteds	Uncorrectables
Downstream 1	21	591.00 MHz	-5.10 dBmV	35.97 dB	256QAM	890596668	1367	943
Downstream 2	17	567.00 MHz	-5.44 dBmV	34.48 dB	256QAM	750136131	443	0
Downstream 3	18	573.00 MHz	-6.26 dBmV	35.08 dB	256QAM	1521010248	3757	0
Downstream 4	19	579.00 MHz	-5.32 dBmV	35.60 dB	256QAM	1518165811	8830	0
Downstream 5	20	585.00 MHz	-5.97 dBmV	35.97 dB	256QAM	1518208059	20975	0
Downstream 6	22	597.00 MHz	-5.62 dBmV	35.97 dB	256QAM	1510201875	29968	0
Downstream 7	23	603.00 MHz	-5.41 dBmV	31.07 dB	256QAM	1508754105	243979	1106
Downstream 8	24	609.00 MHz	-5.69 dBmV	35.25 dB	256QAM	1507523368	11997	0

Reset FEC Counters

Upstream

	UCID	Freq	Power	Channel Type	Symbol Rate	Modulation
Upstream 1	2	22.80 MHz	----	----	----	----
Upstream 2	4	35.60 MHz	49.00 dBmV	DOCSIS2.0 (ATDMA)	5120 kSym/s	64QAM
Upstream 3	3	29.20 MHz	----	----	----	----
Upstream 4	1	16.40 MHz	----	----	----	----

[EG · Accepted solution]

The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. And there is only one channel locked in. There should be 3-5. The downstream power is on the low / weak side as well. 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 book a tech visit to investigate and correct.

[bshyamkumar]

After I changed the splitter, the downstream power improved to -0.5 to -0.7 dBmV with an SNR of 36 to 37dB. However, occasionally the downstream power drops to about -2.0dBmV. This happened a couple of days around 10AM. There are 4 upstream channels with a power level of about 45 dBmV.

When the dowstream power drops to -2 dBmV, the Correcteds and Uncorrectables count goes up and I started losing connectivity. I had to reset my modem to resolve the issue. It is however, significantly better than it was before I swapped the an 8way leviton splitter with Extreme 2way splitter since other cable connections were not being used.

[EG]

Hmmm.., a 2-3 dB power level fluctuation is considered to be normal / typical. It really shouldn't cause much of an increase in bit errors unless the SNR is also dropping down,