Visitor

 • 

5 Messages

Friday, January 24th, 2025 2:57 AM

Internet extremely unstable with new Next Gen Upload modem

I bought a new Coda56 to take advantage of the Next Gen Upload speeds (I verified that they are enabled for my house). My previous modem is an MB8611 and has been pretty much rock solid for me no major issues. There are no splitters on my line, the line from my drop to the modem was replaced two months ago, the drop is relatively new since it was replaced a couple of years ago by a tech for a different problem. The only thing between the pole and my modem is a MoCA filter and a -6db downstream attenuator because otherwise my downstream is screaming in at over 10dbmv.

Hooking up my Coda56 everything seemed fine for a few minutes. I was seeing about 900 mbps down (around the max of my router) and about 160mbps up. The problem is that it's extremely unstable and will need to reconnect to channels every few minutes leaving me without internet while it reconnects. Pings are not great, video calls are almost impossible with ping spikes up to 1 second. Looking at the modem data the problem seems to be the upstream channels. They aren't connecting consistently which is weird because my MB8611 has been just fine. If I could get some help that would be great.

Logs:

No

Time

type

Priority

Event

1

01/23/25 20:58:26

67050300

warning

DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value

2

01/23/25 20:58:09

82001200

warning

RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW; 

3

01/23/25 20:57:54

82000200

critical

No Ranging Response received - T3 time-out;

4

01/23/25 20:57:12

67061601

notice

US profile assignment change. US Chan ID: 41; Previous Profile: 12; New Profile: 11. ;

5

01/23/25 20:57:08

82000200

critical

No Ranging Response received - T3 time-out;

6

01/23/25 20:56:51

67050300

warning

DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;

7

01/23/25 20:56:50

82000200

critical

No Ranging Response received - T3 time-out;

8

01/23/25 20:56:44

85010200

warning

TCS Partial Service;

9

01/23/25 20:56:44

85010300

warning

Initializing Channel Timeout Expires - Time the CM can perform initial ranging on all upstream channels in the TCS has expired;

10

01/23/25 20:56:42

82000200

critical

No Ranging Response received - T3 time-out

11

01/23/25 20:56:19

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

12

01/23/25 20:56:18

82000200

critical

No Ranging Response received - T3 time-out;

13

01/23/25 20:56:17

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

14

01/23/25 20:56:16

82000200

critical

No Ranging Response received - T3 time-out;

15

01/23/25 20:56:15

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

16

01/23/25 20:56:14

82000200

critical

No Ranging Response received - T3 time-out;

17

01/23/25 20:56:13

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

18

01/23/25 20:56:12

82000200

critical

No Ranging Response received - T3 time-out;

19

01/23/25 20:56:12

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

20

01/23/25 20:56:10

82000200

critical

No Ranging Response received - T3 time-out;

Power Levels:

Downstream Overview
Port ID Frequency (Hz) Modulation Signal strength (dBmV) Signal noise ratio (dB) Octets Correcteds Uncorrectables Channel ID
1 517750000 256QAM 4.900 40.946 44589080 0 0 12
2 469750000 256QAM 4.600 40.946 43711039 0 0 4
3 565750000 256QAM 4.700 43.377 43711205 0 0 20
4 613750000 256QAM 3.900 40.946 43711404 0 0 28
5 451750000 256QAM 4.500 40.946 43711619 0 0 1
6 457750000 256QAM 4.700 40.946 43711785 0 0 2
7 463750000 256QAM 4.700 43.377 43711946 0 0 3
8 475750000 256QAM 4.800 40.366 43712108 0 0 5
9 481750000 256QAM 4.800 40.366 43712268 0 0 6
10 487750000 256QAM 4.900 43.377 43712448 0 0 7
11 493750000 256QAM 4.800 43.377 43712608 0 0 8
12 499750000 256QAM 4.800 40.946 43711854 0 0 9
13 505750000 256QAM 4.700 40.946 43713345 0 0 10
14 511750000 256QAM 4.900 40.946 43713027 0 0 11
15 523750000 256QAM 5.000 40.946 43714884 0 0 13
16 529750000 256QAM 4.800 40.946 43715051 0 0 14
17 535750000 256QAM 4.700 40.946 43715519 0 0 15
18 541750000 256QAM 4.600 40.946 43715731 0 0 16
19 547750000 256QAM 4.700 40.366 43715910 0 0 17
20 553750000 256QAM 4.600 40.946 43716374 0 0 18
21 559750000 256QAM 4.700 40.946 43716548 0 0 19
22 571750000 256QAM 4.600 40.946 43716809 0 0 21
23 577750000 256QAM 4.700 40.946 43716970 0 0 22
24 583750000 256QAM 4.800 40.946 43717130 0 0 23
25 589750000 256QAM 4.700 40.946 43714728 0 0 24
26 595750000 256QAM 4.600 40.946 43716961 0 0 25
27 601750000 256QAM 4.400 40.946 43717525 0 0 26
28 607750000 256QAM 4.200 40.946 43717686 0 0 27
29 619750000 256QAM 4.000 40.366 43717354 0 0 29
30 625750000 256QAM 4.300 40.366 43717968 0 0 30
31 631750000 256QAM 4.100 40.366 43718130 0 0 31
32 637750000 256QAM 4.200 40.946 43718298 0 0 32

OFDM Downstream Overview
Receiver FFT type Subcarr 0 Frequency(Hz) PLC locked NCP locked MDC1 locked PLC power(dBmv) SNR(dB) Octets Correcteds Uncorrectables
0 NA NA NO NO NO NA NA NA NA NA
1 4K 803600000 YES YES YES -1.799999 40 20546659 19663826 0

Upsteam overview is empty, nothing is connected.

OFDMA Upstream Overview
Channel Index State Subcarr 0 Frequency(Hz) lin Digital Att Digital Att BW (sc's*fft) Report Power Report Power1_6 FFT Size
0 OPERATE 36200000 0.2334 3.0775 44.4000 64.4326 50.0000 4K
1 DISABLED 0 0.0000 0.0000 0.0000 0.0000 0.0000 2K

For a brief moment I captured upstream channels connected but they didn't last long:


Visitor

 • 

5 Messages

10 days ago

Another set of logs that aren't hugely different but may be helpful or maybe not...

No

Time

type

Priority

Event

1

01/23/25 21:09:58

67050300

warning

DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;

2

01/23/25 21:09:27

85010200

warning

TCS Partial Service;

3

01/23/25 21:09:27

85010300

warning

Initializing Channel Timeout Expires - Time the CM can perform initial ranging on all upstream channels in the TCS has expired;

4

01/23/25 21:09:04

82001200

warning

RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW

5

01/23/25 21:09:04

82000200

critical

No Ranging Response received - T3 time-out;

6

01/23/25 21:09:03

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

7

01/23/25 21:09:01

82000200

critical

No Ranging Response received - T3 time-out;

8

01/23/25 21:08:59

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

9

01/23/25 21:08:59

82000200

critical

No Ranging Response received - T3 time-out;

10

01/23/25 21:08:57

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

11

01/23/25 21:08:57

82000200

critical

No Ranging Response received - T3 time-out;

12

01/23/25 21:08:57

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

13

01/23/25 21:08:55

82000200

critical

No Ranging Response received - T3 time-out

14

01/23/25 21:08:53

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

15

01/23/25 21:08:53

82000200

critical

No Ranging Response received - T3 time-out;

16

01/23/25 21:08:53

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

17

01/23/25 21:08:51

82000200

critical

No Ranging Response received - T3 time-out

18

01/23/25 21:08:51

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out

19

01/23/25 21:08:49

82000200

critical

No Ranging Response received - T3 time-out;

20

01/23/25 21:08:49

82000500

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

(edited)

Visitor

 • 

5 Messages

9 days ago

FWIW I bought an S34 to try that and while it is slightly more stable it's the exact same problem. So this is not a modem related issue.

Official Employee

 • 

1.9K Messages

Good evening @user_ab5f4b! I really appreciate these details, video calls on unstable internet can be a nightmare! I see you also sent us a direct message. Please be reminded that sending unsolicited Direct Messages to an Official Employee of the Xfinity Community Forum, is a violation of Forum Guidelines. In the future we ask that you please wait to be invited before sending a Direct Message.

 

At this time, I’d like to make sure the newest modem is listed as the primary modem on the account, confirm the correct boot file is provisioned to the modem, and check the signals the modem is receiving. I will be responding to your direct message soon

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
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