george_pa07022's profile

Frequent Visitor

 • 

13 Messages

Wed, Jun 29, 2022 7:33 PM

High Upstream Power

Can someone look at these numbers and tell me if upstream power is acceptable?  Modem is Arris SB8200.
Only one splitter (new) after new cable run from pedestal.  All new connectors. All work performed by Comcast.
The upstream power increased from 46-47dBmV after an amplifier was replaced.
Also, I'm receiving multiple errors in the event log:
"CM-STATUS message sent. Event Type Code: 16; Chan ID: 33; DSID: N/A;MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;"
"CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A;MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;"
Eventually, the log clears and is empty.  It doesn't populate again until after a reboot.
Thanks!
Connection

The status listed show the connection state of the cable modem. They are used by your service provider to evaluate the operation of the cable modem.

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 525000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed

Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
13 Locked QAM256 525000000 Hz 3.1 dBmV 40.8 dB 0 0
10 Locked QAM256 507000000 Hz 2.7 dBmV 40.7 dB 1 0
11 Locked QAM256 513000000 Hz 2.8 dBmV 40.7 dB 1 0
12 Locked QAM256 519000000 Hz 3.0 dBmV 40.8 dB 2 0
14 Locked QAM256 531000000 Hz 3.1 dBmV 40.7 dB 1 0
15 Locked QAM256 537000000 Hz 3.3 dBmV 40.7 dB 2 0
16 Locked QAM256 543000000 Hz 3.6 dBmV 40.8 dB 0 0
17 Locked QAM256 549000000 Hz 3.2 dBmV 40.6 dB 0 0
18 Locked QAM256 555000000 Hz 3.0 dBmV 40.4 dB 1 0
19 Locked QAM256 561000000 Hz 3.1 dBmV 40.4 dB 0 0
20 Locked QAM256 567000000 Hz 3.4 dBmV 40.4 dB 0 0
21 Locked QAM256 573000000 Hz 3.5 dBmV 40.3 dB 0 0
22 Locked QAM256 579000000 Hz 3.5 dBmV 40.1 dB 0 0
23 Locked QAM256 585000000 Hz 3.6 dBmV 40.1 dB 0 0
24 Locked QAM256 591000000 Hz 4.1 dBmV 40.4 dB 0 0
25 Locked QAM256 597000000 Hz 4.3 dBmV 40.3 dB 0 0
26 Locked QAM256 603000000 Hz 4.3 dBmV 40.1 dB 0 0
27 Locked QAM256 609000000 Hz 4.5 dBmV 40.0 dB 0 0
28 Locked QAM256 615000000 Hz 4.7 dBmV 40.3 dB 0 0
29 Locked QAM256 621000000 Hz 4.8 dBmV 40.3 dB 0 0
30 Locked QAM256 627000000 Hz 4.9 dBmV 40.2 dB 0 0
31 Locked QAM256 633000000 Hz 5.0 dBmV 40.2 dB 0 0
32 Locked QAM256 639000000 Hz 5.1 dBmV 40.3 dB 0 0
33 Locked Other 693000000 Hz 4.6 dBmV 22.2 dB 1946825270 84197339
34 Not Locked QAM256 0 Hz 0.0 dBmV 40.4 dB 0 0
35 Locked QAM256 645000000 Hz 5.4 dBmV 40.2 dB 0 0
36 Locked QAM256 651000000 Hz 5.2 dBmV 40.2 dB 0 0
37 Locked QAM256 657000000 Hz 5.1 dBmV 40.0 dB 0 0
38 Locked QAM256 663000000 Hz 4.7 dBmV 40.0 dB 0 0
39 Locked QAM256 669000000 Hz 4.4 dBmV 39.3 dB 0 0
40 Locked QAM256 675000000 Hz 4.0 dBmV 39.8 dB 0 0
41 Locked QAM256 681000000 Hz 4.0 dBmV 40.0 dB 0 0



Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 33 Locked SC-QAM Upstream 16400000 Hz 6400000 Hz 51.0 dBmV
2 34 Locked SC-QAM Upstream 22800000 Hz 6400000 Hz 52.0 dBmV
3 35 Locked SC-QAM Upstream 29200000 Hz 6400000 Hz 52.0 dBmV
4 36 Locked SC-QAM Upstream 35600000 Hz 6400000 Hz 52.0 dBmV



Current System Time: Wed Jun 29 14:01:05 2022

EG

Expert

 • 

95K Messages

1 m ago

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

In an 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 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, kinks, sharp bends, etc.

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.

Frequent Visitor

 • 

13 Messages

1 m ago

Thanks for confirming this.  I'm expecting another technician tomorrow (third one).

EG

Expert

 • 

95K Messages

1 m ago

O/k so just bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. And if the problem is found to be on their side of the demarcation point, there will not be any charge. Please post back here with how things turn out.


Good luck !

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