Packet Loss and Low Upstream Power Levels

I'm experiencing upstream packet loss anywhere from 8%-15% during working hours. Is this just network congestion due to working and schooling from home? It obviously makes video and VoIP extremely challenging. It seems to work fine from 6:00 pm until 8:30 am, and fine on weekends.

I've had two technicians out to check the connection. They replaced some cables and removed a splitter, but the problem persists.

The modem (SB8200) shows low upstream power levels, which I've pasted below.

I'd appreciate any help or guidance.

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Responses

aoberdeck

Regular Visitor

•

4 Messages

5 years ago

Here are the power levels:

Downstream Bonded Channels

Channel ID	Lock Status	Modulation	Frequency	Power	SNR/MER	Corrected	Uncorrectables
33	Locked	QAM256	663000000 Hz	5.9 dBmV	40.4 dB	4	0
5	Locked	QAM256	483000000 Hz	2.4 dBmV	39.7 dB	4	0
6	Locked	QAM256	489000000 Hz	2.0 dBmV	39.7 dB	12	0
7	Locked	QAM256	495000000 Hz	1.8 dBmV	39.7 dB	1	0
8	Locked	QAM256	507000000 Hz	3.8 dBmV	40.4 dB	0	0
9	Locked	QAM256	513000000 Hz	4.1 dBmV	40.6 dB	1	0
10	Locked	QAM256	519000000 Hz	3.2 dBmV	40.1 dB	0	0
11	Locked	QAM256	525000000 Hz	2.0 dBmV	39.6 dB	2	0
12	Locked	QAM256	531000000 Hz	0.9 dBmV	39.2 dB	2	0
13	Locked	QAM256	543000000 Hz	1.6 dBmV	39.7 dB	1	0
14	Locked	QAM256	549000000 Hz	2.2 dBmV	39.8 dB	1	0
15	Locked	QAM256	555000000 Hz	2.3 dBmV	39.7 dB	3	0
16	Locked	QAM256	561000000 Hz	2.4 dBmV	39.8 dB	1	0
17	Locked	QAM256	567000000 Hz	2.2 dBmV	39.7 dB	0	0
18	Locked	QAM256	573000000 Hz	2.1 dBmV	39.6 dB	3	0
19	Locked	QAM256	579000000 Hz	2.2 dBmV	39.7 dB	2	0
20	Locked	QAM256	585000000 Hz	2.4 dBmV	39.8 dB	4	0
21	Locked	QAM256	591000000 Hz	2.3 dBmV	39.7 dB	1	0
22	Locked	QAM256	597000000 Hz	2.0 dBmV	39.6 dB	1	0
23	Locked	QAM256	603000000 Hz	1.7 dBmV	38.7 dB	6	0
24	Locked	QAM256	609000000 Hz	1.4 dBmV	38.8 dB	3	0
25	Locked	QAM256	615000000 Hz	1.4 dBmV	39.3 dB	0	0
26	Locked	QAM256	621000000 Hz	1.8 dBmV	39.5 dB	0	0
27	Locked	QAM256	627000000 Hz	2.0 dBmV	39.6 dB	0	0
28	Locked	QAM256	633000000 Hz	2.1 dBmV	39.2 dB	5	0
29	Locked	QAM256	639000000 Hz	2.8 dBmV	39.6 dB	5	0
30	Locked	QAM256	645000000 Hz	3.7 dBmV	40.0 dB	4	0
31	Locked	QAM256	651000000 Hz	5.5 dBmV	40.5 dB	2	0
32	Locked	QAM256	657000000 Hz	6.1 dBmV	40.6 dB	5	0
34	Locked	QAM256	669000000 Hz	5.0 dBmV	40.2 dB	14	0
35	Locked	QAM256	675000000 Hz	4.5 dBmV	39.5 dB	1018	459
36	Locked	QAM256	681000000 Hz	3.8 dBmV	39.9 dB	386	395
159	Locked	Other	722000000 Hz	2.5 dBmV	36.2 dB	30926	0

Upstream Bonded Channels

Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	2	Locked	SC-QAM Upstream	22800000 Hz	6400000 Hz	36.0 dBmV
2	1	Locked	SC-QAM Upstream	16400000 Hz	6400000 Hz	36.0 dBmV
3	3	Locked	SC-QAM Upstream	29200000 Hz	6400000 Hz	37.0 dBmV
4	4	Locked	SC-QAM Upstream	35600000 Hz	6400000 Hz	36.0 dBmV
5	5	Locked	SC-QAM Upstream	40400000 Hz	3200000 Hz	34.0 dBmV

Current System Time: Tue Dec 8 15:53:15 2020

EG

Expert

•

111.4K Messages

5 years ago

The signal stats are in spec. Are there any error log entries being shown anywhere ? If so, please post them as well.

aoberdeck

Regular Visitor

•

4 Messages

5 years ago

Here's what I see in the Event Log:

Date Time Event ID Event Level Description

12/07/2020 16:05	2436694061	5	"Dynamic Range Window violation"
12/07/2020 16:05	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=6c:63:9c:b3:b7:69;CMTS-MAC=dc:eb:94:b4:57:96;CM-QOS=1.1;CM-VER=3.1;"
12/07/2020 16:05	2436694061	5	"Dynamic Range Window violation"
12/07/2020 16:05	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=6c:63:9c:b3:b7:69;CMTS-MAC=dc:eb:94:b4:57:96;CM-QOS=1.1;CM-VER=3.1;"
12/07/2020 16:05	2436694061	5	"Dynamic Range Window violation"
12/07/2020 16:05	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=6c:63:9c:b3:b7:69;CMTS-MAC=dc:eb:94:b4:57:96;CM-QOS=1.1;CM-VER=3.1;"
12/07/2020 16:05	2436694061	5	"Dynamic Range Window violation"
12/07/2020 16:05	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=6c:63:9c:b3:b7:69;CMTS-MAC=dc:eb:94:b4:57:96;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	2436694066	6	"Honoring MDD; IP provisioning mode = IPv6"
01/01/1970 00:00	84000100	3	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:63:9c:b3:b7:69;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12/07/2020 16:05	2436694044	3	"Resetting the cable modem due to docsDevResetNow"

EG

Expert

•

111.4K Messages

5 years ago

The signal stats are o/k but the error log entries indicate that something is going on. Perhaps there is noise ingress into the line(s) somewhere.

There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.

I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They will be able to poll the CMTS to see whether or not everything is in the green zone, see your node / cable plant and modem health, and also see a history plot for the modem. You should get a reply here in your topic. Good luck !

Your Home Network

aoberdeck

Packet Loss and Low Upstream Power Levels

aoberdeck

EG

aoberdeck

EG

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