S

Visitor

 • 

4 Messages

Thursday, August 11th, 2022 3:04 PM

Closed

Arris Modem drops internet connection intermittently

I have a SB8200 modem and the signal has been dropping and the modem reboots on its own. I chatted with an xfinity agent and rebooting my modem and router is not and will not solve the issue. This has been occurring for a couple of weeks but seems more frequent now. I checked the event log of the modem and I am seeing the errors “SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing…” and “No Ranging Response received - T3 time-out;CM-MAC=CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;"”

I can post the full log if someone would be able to take a look at it. I suspect this is an issue is from the line and not my equipment.

Can someone please help? Thank you 

Expert

 • 

107.1K Messages

2 years ago

Yes. Post all of the RF error log entries but please redact any and all of the CM MAC and the CMTS MAC addresses for your privacy. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically.

Please also copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level* numbers and paste them into your next post.

Visitor

 • 

4 Messages

2 years ago

Date Time

Event ID

Event Level

Description

08/11/2022 09:57

74010100

6

"CM-STATUS message sent. Event Type Code: 24; Chan ID: 29; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 09:57

74010100

6

"CM-STATUS message sent. Event Type Code: 24; Chan ID: 29; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 3.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 09:57

74010100

6

"CM-STATUS message sent. Event Type Code: 24; Chan ID: 29; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 09:56

74010100

6

"CM-STATUS message sent. Event Type Code: 16; Chan ID: 29; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:07

67061600

6

"DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:07

2436694066

6

"Honoring MDD; IP provisioning mode = IPv6"

08/11/2022 06:07

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:07

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:06

82000400

3

"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:06

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:06

82000400

3

"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:06

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:05

74010100

6

"CM-STATUS message sent. Event Type Code: 7; Chan ID: 70 71; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:05

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:04

74010100

6

"CM-STATUS message sent. Event Type Code: 7; Chan ID: 70 71; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:04

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:04

74010100

6

"CM-STATUS message sent. Event Type Code: 7; Chan ID: 70 71; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:04

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:03

74010100

6

"CM-STATUS message sent. Event Type Code: 7; Chan ID: 70 71; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:03

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:03

74010100

6

"CM-STATUS message sent. Event Type Code: 7; Chan ID: 70 71; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:03

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000800

3

"16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000600

3

"Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

74010100

6

"CM-STATUS message sent. Event Type Code: 7; Chan ID: 71; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000800

3

"16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000600

3

"Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 06:02

82000500

3

"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:20

67061600

6

"DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:20

2436694066

6

"Honoring MDD; IP provisioning mode = IPv6"

08/11/2022 00:20

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:20

82000400

3

"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:20

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:19

82000800

3

"16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:19

82000300

3

"Ranging Request Retries exhausted;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:19

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:18

74010100

6

"CM-STATUS message sent. Event Type Code: 7; Chan ID: 69 72; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

08/11/2022 00:18

82000200

3

"No Ranging Response received - T3 time-out;CM-MAC=  ;CMTS-MAC= ;CM-QOS=1.1;CM-VER=3.1;"

Visitor

 • 

4 Messages

2 years ago

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
17 Locked QAM256 525000000 Hz 5.4 dBmV 43.1 dB 109 382
14 Locked QAM256 507000000 Hz 5.5 dBmV 42.8 dB 56 223
15 Locked QAM256 513000000 Hz 5.4 dBmV 43.1 dB 90 208
16 Locked QAM256 519000000 Hz 5.5 dBmV 43.2 dB 73 193
18 Locked QAM256 531000000 Hz 5.5 dBmV 43.3 dB 113 327
19 Locked QAM256 537000000 Hz 5.5 dBmV 43.1 dB 123 340
20 Locked QAM256 543000000 Hz 5.3 dBmV 43.1 dB 124 335
21 Locked QAM256 549000000 Hz 5.2 dBmV 42.9 dB 112 368
22 Locked QAM256 555000000 Hz 5.3 dBmV 43.1 dB 123 364
23 Locked QAM256 561000000 Hz 5.4 dBmV 43.1 dB 150 377
24 Locked QAM256 567000000 Hz 5.3 dBmV 43.0 dB 153 450
25 Locked QAM256 573000000 Hz 5.2 dBmV 43.0 dB 144 452
26 Locked QAM256 579000000 Hz 5.3 dBmV 43.1 dB 174 436
27 Locked QAM256 585000000 Hz 5.3 dBmV 43.0 dB 219 487
28 Locked QAM256 591000000 Hz 5.3 dBmV 42.9 dB 231 562
29 Locked Other 693000000 Hz 5.8 dBmV 40.0 dB 636328902 2727
30 Not Locked QAM256 0 Hz 0.0 dBmV 42.8 dB 266 598
31 Locked QAM256 597000000 Hz 5.3 dBmV 42.8 dB 292 641
32 Locked QAM256 603000000 Hz 5.3 dBmV 43.1 dB 318 789
33 Locked QAM256 609000000 Hz 5.3 dBmV 43.0 dB 380 984
34 Locked QAM256 615000000 Hz 5.4 dBmV 43.0 dB 369 1106
35 Locked QAM256 621000000 Hz 5.5 dBmV 42.8 dB 495 1314
36 Locked QAM256 627000000 Hz 5.5 dBmV 43.1 dB 538 1437
37 Locked QAM256 633000000 Hz 5.7 dBmV 42.8 dB 728 1608
38 Locked QAM256 639000000 Hz 5.7 dBmV 43.1 dB 864 1810
39 Locked QAM256 645000000 Hz 5.9 dBmV 42.9 dB 1218 2663
40 Locked QAM256 651000000 Hz 5.9 dBmV 42.8 dB 1239 4121
41 Locked QAM256 657000000 Hz 5.8 dBmV 42.9 dB 1563 4936
42 Locked QAM256 663000000 Hz 6.1 dBmV 43.0 dB 1671 5516
43 Locked QAM256 669000000 Hz 6.1 dBmV 41.1 dB 1930 6243
44 Locked QAM256 675000000 Hz 6.0 dBmV 42.8 dB 2000 6704
45 Locked QAM256 681000000 Hz 5.9 dBmV 42.8 dB 1856 6938



Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 69 Locked SC-QAM Upstream 36500000 Hz 6400000 Hz 41.0 dBmV
2 70 Locked SC-QAM Upstream 30100000 Hz 6400000 Hz 40.0 dBmV
3 71 Locked SC-QAM Upstream 23700000 Hz 6400000 Hz 41.0 dBmV
4 72 Locked SC-QAM Upstream 17300000 Hz 6400000 Hz 40.0 dBmV

Current System Time: Thu Aug 11 12:32:27 2022

New Problem Solver

 • 

617 Messages

Hi @samzilla

 

Thank you for taking the time to reach out and share all the logs with us! We do want to be sure we can look into this and work to get this resolved :) You've come to just the right place! 

 

Please send me a Direct Message so that I can gather some account details. 

Here's the detailed steps to direct message us: 
 • Click "Sign In" if necessary
 • Click the “chat" icon (upper right corner of this page)
 • Click the "New message" (pencil and paper) icon
 • Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
 • Type your message in the text area near the bottom of the window
 • Press Enter to send your message

I no longer work for Comcast.

Expert

 • 

107.1K Messages

2 years ago

The signal status values at that snapshot in time were good but the error log entries and the number of uncorrected bit errors indicate that something is going on. Perhaps there is noise ingress into the line(s) /  an upstream channel / return path impairment somewhere.

There are other signal stat values that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They will be able to poll the CMTS (Cable Modem Termination System) to check for any real-time degradation and / or error reports, see your node / cable plant, and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.


You should get a reply here in your topic. Good luck !

Visitor

 • 

4 Messages

@EG​ Thank you for your assistance! 

Expert

 • 

107.1K Messages

2 years ago

@samzilla 

My pleasure !

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