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4 Messages
Progressively worse connection - any suggestions?
For over 3 months my connectivity has progressively gotten worse, it started with sporadict drops and now it's multiple times a day. I've tried; replacing my modem, replacing my router and having an Comcast technician test to my wall outlet.
It's gotten to a point that we are struggling to keep a connection during work team meetings.
Does anyone have any ideas on how I can get this resolved?
There are multiple critical enteries in my log :
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;; |
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out; |
Started Unicast Maintenance Ranging - No Response received - T3 time-out;
Apply Cancel | |
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. | |
|
Startup Procedure
Procedure | Status | Comment |
Acquire Downstream Channel | 525000000 Hz | Locked |
Connectivity State | OK | Operational |
Boot State | OK | Operational |
Security | Enabled | BPI+ |
IP Provisioning Mode | Honor MDD | honorMdd(4) |
Downstream Bonded Channels
Channel | Lock Status | Modulation | Channel ID | Frequency | Power | SNR | Correctables | Uncorrectables |
1 | Locked | QAM256 | 20 | 525000000 Hz | 1.8 dBmV | 42.3 dB | 5 | 0 |
2 | Locked | QAM256 | 4 | 411000000 Hz | -0.1 dBmV | 41.9 dB | 0 | 0 |
3 | Locked | QAM256 | 5 | 417000000 Hz | 0.1 dBmV | 42 dB | 0 | 0 |
4 | Locked | QAM256 | 6 | 435000000 Hz | 0.3 dBmV | 42 dB | 0 | 0 |
5 | Locked | QAM256 | 7 | 441000000 Hz | 0.1 dBmV | 41.9 dB | 0 | 0 |
6 | Locked | QAM256 | 8 | 453000000 Hz | 0.7 dBmV | 42.3 dB | 0 | 0 |
7 | Locked | QAM256 | 9 | 459000000 Hz | 0.8 dBmV | 42.3 dB | 0 | 0 |
8 | Locked | QAM256 | 10 | 465000000 Hz | 0.8 dBmV | 42.3 dB | 0 | 0 |
9 | Locked | QAM256 | 11 | 471000000 Hz | 0.8 dBmV | 42.2 dB | 0 | 0 |
10 | Locked | QAM256 | 12 | 477000000 Hz | 0.8 dBmV | 42.1 dB | 0 | 0 |
11 | Locked | QAM256 | 13 | 483000000 Hz | 1 dBmV | 42.2 dB | 5 | 0 |
12 | Locked | QAM256 | 14 | 489000000 Hz | 1.3 dBmV | 42.4 dB | 1 | 0 |
13 | Locked | QAM256 | 15 | 495000000 Hz | 1.4 dBmV | 42.3 dB | 0 | 0 |
14 | Locked | QAM256 | 16 | 501000000 Hz | 1.5 dBmV | 42.3 dB | 2 | 0 |
15 | Locked | QAM256 | 17 | 507000000 Hz | 1.6 dBmV | 42.3 dB | 1 | 0 |
16 | Locked | QAM256 | 18 | 513000000 Hz | 1.6 dBmV | 42.3 dB | 9 | 0 |
17 | Locked | QAM256 | 19 | 519000000 Hz | 1.8 dBmV | 42.3 dB | 5 | 0 |
18 | Locked | QAM256 | 21 | 531000000 Hz | 1.8 dBmV | 42.2 dB | 6 | 0 |
19 | Locked | QAM256 | 22 | 537000000 Hz | 1.8 dBmV | 42.2 dB | 6 | 0 |
20 | Locked | QAM256 | 23 | 543000000 Hz | 1.9 dBmV | 42.3 dB | 4 | 0 |
21 | Locked | QAM256 | 24 | 549000000 Hz | 1.9 dBmV | 42.3 dB | 6 | 0 |
22 | Locked | QAM256 | 25 | 555000000 Hz | 2.1 dBmV | 42.3 dB | 4 | 0 |
23 | Locked | QAM256 | 26 | 561000000 Hz | 2.2 dBmV | 42.3 dB | 7 | 0 |
24 | Locked | QAM256 | 27 | 567000000 Hz | 2.1 dBmV | 42.3 dB | 5 | 0 |
25 | Locked | QAM256 | 28 | 573000000 Hz | 2 dBmV | 42.2 dB | 6 | 0 |
26 | Locked | QAM256 | 29 | 579000000 Hz | 1.8 dBmV | 42 dB | 6 | 0 |
27 | Locked | QAM256 | 30 | 585000000 Hz | 1.7 dBmV | 41.9 dB | 10 | 0 |
28 | Locked | QAM256 | 31 | 591000000 Hz | 1.6 dBmV | 41.8 dB | 5 | 0 |
29 | Locked | QAM256 | 32 | 597000000 Hz | 1.7 dBmV | 41.7 dB | 5 | 0 |
30 | Locked | QAM256 | 33 | 603000000 Hz | 1.6 dBmV | 42 dB | 7 | 0 |
31 | Locked | QAM256 | 34 | 609000000 Hz | 1.3 dBmV | 41.9 dB | 5 | 0 |
32 | Not Locked | Unknown | 0 | 0 Hz | 0.0 dBmV | 0.0 dB | 0 | 0 |
Upstream Bonded Channels
Channel | Lock Status | US Channel Type | Channel ID | Symbol Rate | Frequency | Power |
1 | Locked | ATDMA | 2 | 5120 Ksym/sec | 22800000 Hz | 50.5 dBmV |
2 | Locked | ATDMA | 3 | 5120 Ksym/sec | 29200000 Hz | 49.3 dBmV |
3 | Locked | ATDMA | 4 | 5120 Ksym/sec | 35600000 Hz | 47.8 dBmV |
4 | Locked | ATDMA | 5 | 1280 Ksym/sec | 40400000 Hz | 45 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 |
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 ,1 ,2 ,3 | 48 | 722000000 Hz | 3.5 dBmV | 41.7 dB | 1228 ~ 2867 | 531412734 | 726 | 0 |
2 | Not Locked | 0 | 0 | 0 Hz | 0 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 | 0 | 0 | 0 Hz | 0 dBmV |
2 | Not Locked | 0 | 0 | 0 Hz | 0 dBmV |
Extended Upstream Transmit PowerEnable Extended Upstream Transmit Power
Current System Time:Mon Oct 12 14:20:55 2020System Up Time:12:31:13
EG
Expert
•
111.5K Messages
5 years ago
The upstream power is high and it may be intermittently fluctuating even higher to out of spec levels. 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 get the techs re-involved until it is fixed properly. Good luck !
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EG
Expert
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111.5K Messages
5 years ago
It's too high. "Attenuators" can't lower the upstream power, they make it higher ! Attenuators lower the downstream power. Is that what you meant to say ?
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BELL5
New Poster
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4 Messages
5 years ago
EG, thank you for the reply and the troubleshooting steps.
Last week the Comcast technician did place an attenuator to lower the upstream power.
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BELL5
New Poster
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4 Messages
5 years ago
Now I'm second guessing the conversation. I recall he said something was too high and that he placed something on the coax to correct it.
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EG
Expert
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111.5K Messages
5 years ago
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BELL5
New Poster
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4 Messages
5 years ago
I couldn't find the cable that the tech had placed the attenuator on, there are half a dozen coax cables in my attic for some reason!
Like clockwork my connection went down again. It seems to happen around 1pm - 2pm CST everyday and then again later in the evening.
Startup Procedure
Downstream Bonded Channels
Upstream Bonded Channels
Downstream OFDM Channels
Status
Profile ID
ID
MER
Number Range
Codewords
Codewords
Codewords
Upstream OFDMA Channels
Extended Upstream Transmit PowerEnable Extended Upstream Transmit Power
Current System Time:Tue Oct 13 12:41:48 2020System Up Time:1 day 10:52:06
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EG
Expert
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111.5K Messages
5 years ago
It's still too high. Perhaps it would be best to get another tech out to investigate / correct the problem. Good luck with it !
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XfinityAmira
Official Employee
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4.2K Messages
5 years ago
Hello @BELL5, thanks for reaching out to us on our Forums page. We appreciate you being a customer with us, and I apologize for the connection issues you have recently been experiencing. We definitely understand how important it is to have a steady and consistent connection. I can imagine how inconvenient and frustrating these connection issues must be. We would love to help! I see you have already sent me a private message and I will respond promptly.
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