We upgraded to 600 MBPS service recently from 150 MBPS and it may or may not be related but I have been getting random disconnects. It happened again this morning 3 times, and the 3rd time it stayed down for hours. Rebooted modem, router, etc multiple times, checked all connections even though nothing has changed.
I set up a tech appt. For reference we have a CM600 modem which is a docsis 3.0 modem which I dont think fully supports our new service speed but it should still provide the same solid service as we had before. When it went down the last time I checked and we had 1 downstream channel locked and that was it. No upstream. I took a shower, came back and the modem is connected again, except now, I only have 1 of 4 upstream channels locked, and my power levels look too high. All downsteam channels are locked.
| Startup Procedure |
| Procedure |
Status |
Comment |
| Acquire Downstream Channel |
405000000 Hz |
Locked |
| Connectivity State |
OK |
Operational |
| Boot State |
OK |
Operational |
| Security |
Enable |
BPI+ |
| IP Provisioning Mode |
Honor MDD |
IPv6 only |
|
|
|
| Downstream Bonded Channels |
| Channel |
Lock Status |
Modulation |
Channel ID |
Frequency |
Power |
SNR |
Correctables |
Uncorrectables |
| 1 |
Locked |
QAM256 |
8 |
405000000 Hz |
-3.5 dBmV |
37.5 dB |
0 |
0 |
| 2 |
Locked |
QAM256 |
9 |
411000000 Hz |
-3.5 dBmV |
37.4 dB |
0 |
0 |
| 3 |
Locked |
QAM256 |
10 |
417000000 Hz |
-3.5 dBmV |
37.5 dB |
0 |
0 |
| 4 |
Locked |
QAM256 |
11 |
423000000 Hz |
-3.3 dBmV |
38.0 dB |
0 |
0 |
| 5 |
Locked |
QAM256 |
12 |
429000000 Hz |
-3.4 dBmV |
38.0 dB |
0 |
0 |
| 6 |
Locked |
QAM256 |
13 |
435000000 Hz |
-3.3 dBmV |
38.1 dB |
0 |
0 |
| 7 |
Locked |
QAM256 |
14 |
441000000 Hz |
-3.4 dBmV |
38.1 dB |
0 |
0 |
| 8 |
Locked |
QAM256 |
15 |
447000000 Hz |
-3.5 dBmV |
38.2 dB |
0 |
0 |
| 9 |
Locked |
QAM256 |
16 |
453000000 Hz |
-3.6 dBmV |
38.2 dB |
0 |
0 |
| 10 |
Locked |
QAM256 |
17 |
459000000 Hz |
-3.8 dBmV |
38.1 dB |
0 |
0 |
| 11 |
Locked |
QAM256 |
18 |
465000000 Hz |
-4.0 dBmV |
38.1 dB |
0 |
0 |
| 12 |
Locked |
QAM256 |
19 |
471000000 Hz |
-4.1 dBmV |
38.4 dB |
0 |
0 |
| 13 |
Locked |
QAM256 |
20 |
477000000 Hz |
-4.2 dBmV |
38.2 dB |
0 |
0 |
| 14 |
Locked |
QAM256 |
21 |
483000000 Hz |
-4.3 dBmV |
38.1 dB |
0 |
0 |
| 15 |
Locked |
QAM256 |
22 |
489000000 Hz |
-4.4 dBmV |
38.0 dB |
0 |
0 |
| 16 |
Locked |
QAM256 |
23 |
495000000 Hz |
-4.4 dBmV |
37.7 dB |
0 |
0 |
| 17 |
Locked |
QAM256 |
24 |
501000000 Hz |
-4.9 dBmV |
37.9 dB |
0 |
0 |
| 18 |
Locked |
QAM256 |
25 |
507000000 Hz |
-4.8 dBmV |
37.9 dB |
0 |
0 |
| 19 |
Locked |
QAM256 |
26 |
513000000 Hz |
-4.7 dBmV |
37.9 dB |
0 |
0 |
| 20 |
Locked |
QAM256 |
27 |
519000000 Hz |
-4.9 dBmV |
38.0 dB |
0 |
0 |
| 21 |
Locked |
QAM256 |
28 |
525000000 Hz |
-4.8 dBmV |
38.2 dB |
0 |
0 |
| 22 |
Locked |
QAM256 |
29 |
531000000 Hz |
-4.5 dBmV |
38.2 dB |
0 |
0 |
| 23 |
Locked |
QAM256 |
30 |
537000000 Hz |
-4.3 dBmV |
38.2 dB |
0 |
0 |
| 24 |
Locked |
QAM256 |
31 |
543000000 Hz |
-4.0 dBmV |
38.6 dB |
0 |
0 |
|
|
|
| Upstream Bonded Channels |
| Channel |
Lock Status |
US Channel Type |
Channel ID |
Symbol Rate |
Frequency |
Power |
| 1 |
Locked |
ATDMA |
3 |
5120 Ksym/sec |
30300000 Hz |
57.0 dBmV |
| 2 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0.0 dBmV |
| 3 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0.0 dBmV |
| 4 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0.0 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 |
|
EG
Expert
•
111.5K Messages
5 years ago
That modem is rated by them for up to 959 Mbps speeds;
https://www.xfinity.com/support/devices#details
The upstream power is way too high / out of spec ! That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.
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.
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