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cm1000 and xfinity issues or just Docsis 3.1 issue?
Hello all. I upgraded to the Gigabit plan with Xfinity. I use my own Modem (Arris Surfboard 3.0). After realizing I needed a Docsis 3.1 I bought the Motorola MB8600 or whatever but it was 3.1. Comcast...
I am having the same set of issues with Comcast in Seattle area. Anyone know what I can do to debug why the CM1000 is so spotty? Every few days I lose all connectivity and have to reboot the modem. Downloaded latest patches. With previous modem the thing would work for months no issues. My wife is saying I paid out the nose for CM1000 and the thing is much worse than the 30$ Motorola we used in the past. Can't really argue with her.
To debug I wrote a program to periodically connect ever 15 seconds to a remote site and verify connectivity. Sure enough about every 1-2 days I lose all connectivity and it does not recover. Have to cold boot modem. The logging on the modem looks pretty shoddy, how can I debug this thing?
Note here are my stats, look pretty good:
Cable Connection
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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
639000000
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 639000000 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 / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 25 639000000 Hz -1.0 dBmV 38.0 dB 224514965 97 0
2 Locked QAM256 1 483000000 Hz -1.0 dBmV 38.8 dB 221670518 6 0
3 Locked QAM256 2 489000000 Hz -0.7 dBmV 38.8 dB 221684214 1 0
4 Locked QAM256 3 495000000 Hz 0.0 dBmV 38.8 dB 221697351 2 0
5 Locked QAM256 4 507000000 Hz -1.7 dBmV 38.5 dB 221709990 2 0
6 Locked QAM256 5 513000000 Hz -3.3 dBmV 38.4 dB 221722831 3 0
7 Locked QAM256 6 519000000 Hz -3.3 dBmV 38.4 dB 221735725 8 0
8 Locked QAM256 7 525000000 Hz -2.2 dBmV 38.5 dB 221749433 5 0
9 Locked QAM256 8 531000000 Hz -1.8 dBmV 38.5 dB 221762336 10 0
10 Locked QAM256 9 543000000 Hz -2.0 dBmV 38.4 dB 221775443 8 0
11 Locked QAM256 10 549000000 Hz -2.9 dBmV 38.2 dB 221788520 8 0
12 Locked QAM256 11 555000000 Hz -3.0 dBmV 38.1 dB 221801376 18 0
13 Locked QAM256 12 561000000 Hz -2.5 dBmV 38.2 dB 221822634 20 0
14 Locked QAM256 13 567000000 Hz -2.2 dBmV 38.2 dB 221836130 17 0
15 Locked QAM256 14 573000000 Hz -1.9 dBmV 38.3 dB 221848501 25 0
16 Locked QAM256 15 579000000 Hz -2.1 dBmV 38.2 dB 221862091 28 0
17 Locked QAM256 16 585000000 Hz -2.0 dBmV 38.2 dB 221875431 27 0
18 Locked QAM256 17 591000000 Hz -1.9 dBmV 38.1 dB 221888649 24 0
19 Locked QAM256 18 597000000 Hz -1.5 dBmV 38.0 dB 221901593 44 0
20 Locked QAM256 19 603000000 Hz -1.2 dBmV 38.1 dB 221914425 37 0
21 Locked QAM256 20 609000000 Hz -1.1 dBmV 38.1 dB 221927939 54 0
22 Locked QAM256 21 615000000 Hz -1.1 dBmV 38.0 dB 221941485 57 0
23 Locked QAM256 22 621000000 Hz -1.3 dBmV 38.2 dB 221954893 46 0
24 Locked QAM256 23 627000000 Hz -1.5 dBmV 38.0 dB 221967464 80 0
25 Locked QAM256 24 633000000 Hz -1.2 dBmV 37.8 dB 221980886 71 0
26 Locked QAM256 26 645000000 Hz -1.0 dBmV 37.7 dB 221993619 79 0
27 Locked QAM256 27 651000000 Hz -1.2 dBmV 37.7 dB 222007106 111 0
28 Locked QAM256 28 657000000 Hz -1.5 dBmV 37.8 dB 222020222 81 0
29 Locked QAM256 29 663000000 Hz -1.4 dBmV 37.6 dB 222031542 87 0
30 Locked QAM256 30 669000000 Hz -1.2 dBmV 37.7 dB 222039345 75 0
31 Locked QAM256 31 675000000 Hz -1.3 dBmV 37.3 dB 222046242 86 0
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0
Upstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 30100000 Hz 63.3 dBmV
2 Not Locked Unknown 0 0 Hz 0.0 dBmV
3 Not Locked Unknown 0 0 Hz 0.0 dBmV
4 Not Locked Unknown 0 0 Hz 0.0 dBmV
5 Not Locked Unknown 0 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 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 0 159 745000000 Hz -0.8 dBmV 36.8 dB 1126 ~ 2969 188572963 0 0
2 Not Locked 0 0 0 Hz -4.3 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 Unknown 0 0 Hz 0 dBmV
2 Not Locked Unknown 0 0 Hz 0 dBmV
Current System Time: Tue Apr 03 18:44:45 2018
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All the levels look fine. Do you get any T3 or T4 timeouts in the logs?
DarrenM
Yes, lots of T3 timeouts.
Bought brand new Motorola MB8600, same spotty connectivity issues. Same T3 timeouts in log. Working to get Comcast out to my house to investigate. Comcast tech claimed to have "boosted" the signal of my modem via some mystical remote software patch of my modem. Still same problem.
