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

Hi,

I have a direct coaxial connection from the pole straight to the modem without splitter in betweens. The cable was replaced couple years ago.

We have intermittent connection issue where the connection would drop for couple minutes and come back. It happened frequently enough to impact services, for example, our ring camera would be streaming and recording an event during which everything freezes for a good while after the object of interest that triggers the recording goes out of frame and no where to be found.

We were diagnosing the issue ourselves and swapped between modems to isolate modem hardware issues.

We used sb6183 and sb6141

(the retail version IS still supported and not EOL. You can find it in the approved device list. Only lease version is EOL).

Below logs are from sb6141, but the sb6183 had basically identical errors:

Checked 192.168.100.1 - bunch of critical T3 and T4 timeout:

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=macaddress;CMTS-MAC=macaddress;CM-QOS=1.1;CM-VER=3.0;

No Ranging Response received - T3 time-out;CM-MAC=macaddress;CMTS-MAC=macaddress;CM-QOS=1.1;CM-VER=3.0;

Cable Modem Reboot due to T4 timeout ;CM-MAC=macaddress;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=macaddress;CMTS-MAC=macaddress;CM-QOS=1.1;CM-VER=3.0;

No Ranging Response received - T3 time-out;CM-MAC=macaddress;CMTS-MAC=macaddress;CM-QOS=1.1;CM-VER=3.0;

Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=macaddress;CMTS-MAC=macaddress;CM-QOS=1.1;CM-VER=3.0;

No Ranging Response received - T3 time-out;CM-MAC=macaddress;CMTS-MAC=macaddress;CM-QOS=1.1;CM-VER=3.0;

Signals as far as I can tell are stellar:

Downstream 8 channels: SNR: 37-38 dB, power level 0dbmv - 2dBmv

Upstream 4 channels: power level 36-37 dBmv

We have had tech came out in the past which did not fix the issue and attempted to charge the account for a tech visit service fee.

I searched some older post, it appears the problem should be from comcast's side. Please help investigate.