my XFINITY Internet connection is currently getting disconnected several times an hour between 1 and 20 minutes. Often it works fine for hours and then it starts failing. I am not sure if this type of behavior can be triggered by some type of interference from neighbors or weather. Maybe an Xfinity pole/amplifier or even switch/node issues .. who knows. I think I checked pretty much everything I can on my side of the network.
The modem status show between 20 and 200 uncorrectables/channel & hour (corrected number is 20-40% of that)
I need to restart the modem several times a day. This recovers service for a while.
The modem also resets automatically due to T3/T4 timeouts
Scanning the system through Xfinity Status center often shows no issues at all.
The Xfinity outage map shows no outages at my address (zip: 30066), however, it has been showing an exclamation mark in the ZIP code area indicating unplanned outages for 51 .. 500 subscribers ( this value fluctuated from zero to 2,000 throughout the past four weeks).
modem: SB6183 (also tested with ASUS CM-16), Signal levels 7-11 dBmV down, 40-45dBmV up
service: 100 Mbps (things were better at lower speed, I upgraded the service just around the time these issues started. Coincidence? That's also the time everyone was stuck at home with the home office.
Actions taken:
hours of tech support chat for over four weeks now
restart modem usually works (through Xfinity website and power cycling)
modem reset to factory settings
Xfinity checked outside line; added MoCa filter
replaced modem .. different brand, same issues
added splitter to cool down signals .. issues even worse (more frequent)
running test software for detailed info about up/downtime (ping three sites, 5 sec increment, show error if the response is > 250ms for more than 20 seconds - typical response time is < 10ms)
Excerpts from ASUS router log info:
Jul 13 09:38:41 nat: apply redirect rules
Jul 13 09:38:47 WAN_Connection: ISP's DHCP did not function properly.
[…]
Jul 13 09:39:48 WAN_Connection: WAN was restored.
Jul 14 14:35:46 WAN_Connection: ISP's DHCP did not function properly.
Here are a few entries typically found in the cable modem event log:
No ranging response received T3 timeout.
16 consecutive T3 timeouts while trying to range on upstream channel 3
Started Unicast Maintenance Ranging - No Response received - T3 time-out
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
UPDATE (16JUL2020)
I found a post that described the exact same issue. It was resolved by fixing the line/equipment outside the house (defective booster on the pole) The poster is using the same tools I am using to track outages and posts the same type of status/event logs I can see on my modem. So instead of repeating all this, please refer to
https://forums.xfinity.com/t5/Your-Home-Network/Intermittent-dropped-internet/td-p/3254091/page/2 I'll have an Xfinity technician have a look at it tomorrow and I hope they will fix the issue.
