A couple of weeks ago started to have intermittent connection issues. (PALO ALTO, CA) First Comcast suspected a hardware issue and sent me a new device that didn't help. (I tried a total of 3 different routers)
So I went and bought my own Netgear C7800 and now I have access to more detailed logs:
| Time Not Established |
Notice (6) |
Honoring MDD; IP provisioning mode = IPv6 |
| Time Not Established |
Critical (3) |
No Ranging Response received - T3 time-out;CM-MAC=[HIDDEN];CMTS-MAC=[HIDDEN];CM-QOS=1.1;CM-VER=3.1; |
| Time Not Established |
Critical (3) |
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:[HIDDEN];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; |
| Time Not Established |
Critical (3) |
No Ranging Response received - T3 time-out;CM-MAC=cc:[HIDDEN];CMTS-MAC=[HIDDEN];CM-QOS=1.1;CM-VER=3.1; |
| Time Not Established |
Critical (3) |
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:[HIDDEN];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; |
| <tabindex=-1>Startup Procedure</tabindex=-1> |
| 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 |
IPv6 only |
|
|
| <tabindex=-1>Downstream Bonded Channels</tabindex=-1> |
| Channel |
Lock Status |
Modulation |
Channel ID |
Frequency |
Power |
SNR |
Correctables |
Uncorrectabables |
| 1 |
Locked |
QAM256 |
20 |
525000000 Hz |
2.3 dBmV |
41.3 dB |
0 |
0 |
| 2 |
Locked |
QAM256 |
8 |
447000000 Hz |
2.9 dBmV |
41.7 dB |
0 |
0 |
| 3 |
Locked |
QAM256 |
9 |
453000000 Hz |
2.9 dBmV |
41.6 dB |
0 |
0 |
| 4 |
Locked |
QAM256 |
10 |
459000000 Hz |
2.9 dBmV |
41.6 dB |
0 |
0 |
| 5 |
Locked |
QAM256 |
11 |
465000000 Hz |
2.8 dBmV |
41.6 dB |
0 |
0 |
| 6 |
Locked |
QAM256 |
12 |
471000000 Hz |
2.8 dBmV |
41.5 dB |
0 |
0 |
| 7 |
Locked |
QAM256 |
13 |
477000000 Hz |
2.8 dBmV |
41.5 dB |
0 |
0 |
| 8 |
Locked |
QAM256 |
14 |
483000000 Hz |
2.7 dBmV |
41.6 dB |
0 |
0 |
| 9 |
Locked |
QAM256 |
15 |
489000000 Hz |
2.8 dBmV |
41.4 dB |
0 |
0 |
| 10 |
Locked |
QAM256 |
16 |
495000000 Hz |
2.5 dBmV |
41.1 dB |
0 |
0 |
| 11 |
Locked |
QAM256 |
17 |
507000000 Hz |
2.4 dBmV |
41.1 dB |
0 |
0 |
| 12 |
Locked |
QAM256 |
18 |
513000000 Hz |
2.5 dBmV |
41.2 dB |
0 |
0 |
| 13 |
Locked |
QAM256 |
19 |
519000000 Hz |
2.5 dBmV |
41.1 dB |
0 |
0 |
| 14 |
Locked |
QAM256 |
21 |
531000000 Hz |
2.4 dBmV |
41.0 dB |
0 |
0 |
| 15 |
Locked |
QAM256 |
22 |
537000000 Hz |
2.2 dBmV |
41.1 dB |
0 |
0 |
| 16 |
Locked |
QAM256 |
23 |
543000000 Hz |
2.1 dBmV |
41.0 dB |
0 |
0 |
| 17 |
Locked |
QAM256 |
24 |
549000000 Hz |
2.3 dBmV |
41.2 dB |
0 |
0 |
| 18 |
Locked |
QAM256 |
25 |
555000000 Hz |
2.1 dBmV |
40.9 dB |
0 |
0 |
| 19 |
Locked |
QAM256 |
26 |
561000000 Hz |
2.1 dBmV |
40.9 dB |
0 |
0 |
| 20 |
Locked |
QAM256 |
27 |
567000000 Hz |
2.0 dBmV |
41.0 dB |
0 |
0 |
| 21 |
Locked |
QAM256 |
28 |
573000000 Hz |
1.9 dBmV |
41.0 dB |
0 |
0 |
| 22 |
Locked |
QAM256 |
29 |
579000000 Hz |
1.9 dBmV |
40.9 dB |
0 |
0 |
| 23 |
Locked |
QAM256 |
30 |
585000000 Hz |
1.7 dBmV |
40.9 dB |
0 |
0 |
| 24 |
Locked |
QAM256 |
31 |
591000000 Hz |
1.7 dBmV |
40.9 dB |
0 |
0 |
| 25 |
Locked |
QAM256 |
32 |
597000000 Hz |
1.7 dBmV |
40.9 dB |
0 |
0 |
| 26 |
Locked |
QAM256 |
33 |
603000000 Hz |
1.7 dBmV |
40.8 dB |
0 |
0 |
| 27 |
Locked |
QAM256 |
34 |
609000000 Hz |
1.5 dBmV |
41.0 dB |
0 |
0 |
| 28 |
Locked |
QAM256 |
35 |
615000000 Hz |
1.3 dBmV |
40.8 dB |
0 |
0 |
| 29 |
Locked |
QAM256 |
36 |
621000000 Hz |
1.2 dBmV |
40.6 dB |
0 |
0 |
| 30 |
Locked |
QAM256 |
37 |
627000000 Hz |
0.7 dBmV |
40.5 dB |
0 |
0 |
| 31 |
Locked |
QAM256 |
38 |
633000000 Hz |
0.7 dBmV |
40.5 dB |
0 |
0 |
| 32 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
0.0 dB |
0 |
0 |
|
|
| <tabindex=-1>Upstream Bonded Channels</tabindex=-1> |
| Channel |
Lock Status |
US Channel Type |
Channel ID |
Symbol Rate |
Frequency |
Power |
| 1 |
Locked |
ATDMA |
10 |
1280 Ksym/sec |
41200000 Hz |
42.0 dBmV |
| 2 |
Locked |
ATDMA |
7 |
5120 Ksym/sec |
23700000 Hz |
40.3 dBmV |
| 3 |
Locked |
ATDMA |
9 |
5120 Ksym/sec |
36700000 Hz |
40.5 dBmV |
| 4 |
Locked |
ATDMA |
8 |
5120 Ksym/sec |
30300000 Hz |
40.5 dBmV |
| 5 |
Locked |
ATDMA |
6 |
5120 Ksym/sec |
17300000 Hz |
39.8 dBmV |
| 6 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0 dBmV |
| 7 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0 dBmV |
| 8 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0 dBmV |
|
In addition, I noticed that after the errors above I noticed that it's not actually the internet or connection dropping it appears that the router is unable to assign an IPv4 address or the devices don't seem to "accept them" - I have no idea why= maybe it has to do with the time sync issue.
- All devices are set to get their IP address automatically via DHCP.
- It affects both ethernet and wifi connected devices
- There are no IP conflict devices simply don't "accept/lose" their Ipv4 address
- IPv6 address seems to be assigned fine but this might be due to the standard setting of my router for Ipv6
- Renewing DCHP lease doesn't seem to have any effect
- Restarting the modem doesn't seem to really help
- The modem/router is set to be DHCP server
- there is no WIFI interference
- I also had a technician here already who confirmed that the connection to the house and to the modem is stable without any loss
- I also ruled out hardware issues as I tried the connection with 3 different devices (all of which I of course added and removed via Xfinity Customer support) 2 were Xfinity rented devices and the current one is a Netgear C7800
- Firmware is up-to-date
About 48h ago the issues seemed to have "fixed itself" for about 24h but returned yesterday afternoon. For the last 2 weeks, I wasn't able to reliably use my internet for about 90% of the time
I spent a total of 9h-13h with various support lines without any luck- I have another technician appointment today. but honestly not much hope for that to solve the issue.
