Community Forum

Intermittent Dropping and Weak Speeds with Gigabit Xfinity

Highlighted
New Poster

Intermittent Dropping and Weak Speeds with Gigabit Xfinity

Hello, 

 

I have been a long time Xfinity customer. We just recently upgraded to gigabit and were very excited. We have recently started stressing the bandwidth since being in quarantine. 

 

In short, we have had intermittent issues either dropping out at least once a day or bandwidth simply dropping to below 5 mbps. We also only get about max 150 right next to the gateway w/ 5 min fluxuations to 450 then back down. 

 

We had an old Netgear C7800 modem/router combo set to bridge mode w/ Eero as router. I have now swapped the netgear for a SB8200.

 

I have looked at other posts, so if it helps here are the stats from my modem:

 

Screen Shot 2020-04-20 at 9.30.41 AM.pngScreen Shot 2020-04-20 at 9.30.59 AM.pngScreen Shot 2020-04-20 at 9.30.56 AM.png


 Any help would be appreciated. Thank you!

Highlighted
New Poster

Re: Intermittent Dropping and Weak Speeds with Gigabit Xfinity

Replying with the data since it looks like the photos did not take the first time:

 

Procedure Status Comment
Acquire Downstream Channel 489000000 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
2 Locked QAM256 489000000 Hz 3.1 dBmV 40.5 dB 20 32
3 Locked QAM256 495000000 Hz 3.2 dBmV 40.4 dB 31 30
4 Locked QAM256 501000000 Hz 3.5 dBmV 40.5 dB 32 29
5 Locked QAM256 507000000 Hz 3.8 dBmV 40.5 dB 29 32
6 Locked QAM256 513000000 Hz 3.6 dBmV 40.4 dB 11 31
7 Locked QAM256 519000000 Hz 3.6 dBmV 40.5 dB 18 29
8 Locked QAM256 525000000 Hz 3.3 dBmV 40.5 dB 12 29
9 Locked QAM256 531000000 Hz 3.2 dBmV 40.6 dB 8 34
10 Locked QAM256 537000000 Hz 3.6 dBmV 40.5 dB 21 31
11 Locked QAM256 543000000 Hz 3.6 dBmV 40.6 dB 12 31
12 Locked QAM256 549000000 Hz 3.8 dBmV 40.6 dB 39 34
13 Locked QAM256 555000000 Hz 3.5 dBmV 40.6 dB 19 30
14 Locked QAM256 561000000 Hz 3.2 dBmV 40.5 dB 8 33
15 Locked QAM256 567000000 Hz 3.1 dBmV 40.4 dB 7 32
16 Locked QAM256 573000000 Hz 2.6 dBmV 40.3 dB 14 29
17 Locked QAM256 579000000 Hz 2.8 dBmV 40.4 dB 13 30
18 Locked QAM256 585000000 Hz 2.8 dBmV 40.5 dB 10 34
19 Locked QAM256 591000000 Hz 2.8 dBmV 40.4 dB 8 35
20 Locked QAM256 597000000 Hz 2.7 dBmV 40.3 dB 17 32
21 Locked QAM256 603000000 Hz 2.6 dBmV 40.3 dB 12 28
22 Locked QAM256 609000000 Hz 2.3 dBmV 40.2 dB 18 33
23 Locked QAM256 615000000 Hz 1.9 dBmV 40.1 dB 12 27
24 Locked QAM256 621000000 Hz 1.8 dBmV 40.1 dB 13 31
25 Locked QAM256 627000000 Hz 1.4 dBmV 39.8 dB 19 30
26 Locked QAM256 633000000 Hz 1.7 dBmV 40.0 dB 13 33
27 Locked QAM256 639000000 Hz 1.2 dBmV 39.8 dB 16 29
28 Locked QAM256 645000000 Hz 1.6 dBmV 39.9 dB 8 31
29 Locked QAM256 651000000 Hz 1.1 dBmV 39.7 dB 11 28
30 Locked QAM256 657000000 Hz 0.6 dBmV 39.6 dB 19 30
31 Locked QAM256 663000000 Hz 0.5 dBmV 39.5 dB 7 28
32 Locked QAM256 669000000 Hz 0.4 dBmV 39.4 dB 8 34
37 Locked Other 690000000 Hz 0.6 dBmV 37.0 dB 163030398 0

 

 

Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 86 Locked SC-QAM Upstream 29400000 Hz 6400000 Hz 43.0 dBmV
2 85 Locked SC-QAM Upstream 35800000 Hz 6400000 Hz 44.0 dBmV
3 87 Locked SC-QAM Upstream 23000000 Hz 6400000 Hz 43.0 dBmV
4 88 Locked SC-QAM Upstream 16600000 Hz 6400000 Hz 42.0 dBmV

 

Event Log:

04/19/2020 23:16 74010100 6 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 23:16 74010100 6 "CM-STATUS message sent. Event Type Code: 22; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 23:16 74010100 6 "CM-STATUS message sent. Event Type Code: 23; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 23:16 74010100 6 "CM-STATUS message sent. Event Type Code: 16; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 23:16 74010100 6 "CM-STATUS message sent. Event Type Code: 20; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 18:13 67061600 6 "DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 2436694066 6 "Honoring MDD; IP provisioning mode = IPv6"
01/01/1970 00:00 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 18:04 84000500 3 "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:04 84000500 3 "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:04 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:03 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:02 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:02 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:02 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 17:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 16:06 82000400 3 "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 16:06 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 16:06 82000400 3 "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 16:06 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 16:03 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 16:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 15:58 2436694044 3 "Resetting the cable modem due to docsDevResetNow"
01/01/1970 00:00 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
04/19/2020 15:53 84000500 3 "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 82000200 3 "No Ranging Response received - T3 time-out;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:01:5c:84:c0:5b;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84000200 3 "SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84000200 3 "SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:01 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00 2436694048 3 "Telnet user logged in from IP address 192.168.100.101."
01/01/1970 00:00 84000100 3 "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a4:98:13:fc:e9:7d;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
Highlighted
New Poster

Re: Intermittent Dropping and Weak Speeds with Gigabit Xfinity

I had a different same issue with another Netgear modem/router (C7800). When I looked at the logs there were also time and sychronization failures, so this might help.

 

The issue is related to a firmware update (V3.01.43) that is pushed out from the ISP (which now has to do all the firmware updates). Unplug the coax or ethernet from the ISP. Push in the factory reset button on the modem (one that you need to use a paperclip, small hole usually next to the power button). Then re-hook the cable or etherent connection. this should resync the ISP and  firmware should update. Even though I pressed the factory reset button, all of my setting were still there after it reintialized.

Hope this helps. I got the solution from Reddit and not Netgear or Xfinity.