Help diagnosing video conference problems

@MNtundraRET​ Mostly Zoom, but I've also had the problem with Google Meet.

I think it's significant that a different tool (Blip) sees packet loss at the same time I have trouble in the video conference. I'm pretty sure the problem is not caused by the video conference software (though perhaps some conference software may deal with packet loss better than others.)

I have used Zoom, Teams, and others, but not Google Meet. Never a problem but I have always used DSL through the phone company for broadband Internet since Netscape days. It does sound like the problem is through Comcast Internet. An employee should come along to help you here.

@flatlander3​ Thanks for the suggestion. Turns out I do indeed have events in the Arris log--a bunch of them from last night. I was not on video conferences last night, though we were (successfully) streaming a movie at the time of these log events. I'm not sure what these log events mean, and I don't know if they are related to my conferencing problems, but FWIW here they are:

@Vinndalf 

The image of the error log entries in your post has been removed due to it containing your modem's CM MAC address and the CMTS MAC address which 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.

What you can do instead is copy and paste all of the text (instead of using an image) but you'll need to redact all of the CM MAC and CMTS MAC addresses, then paste them into your next post here. 

@Vinndalf​ I think that was useless. After more monitoring of pings to all steps on tracert, I can see that Blip sometimes shows packet loss even when ping reports none reaching any individual step on the tracert. I'm writing this part off as an inconclusive experiment.

@flatlander3​ Thanks. I've uploaded a redacted version of the log above, and I'm working through the troubleshooting document you sent. I've not confronted modem power levels before. The status page on my Arris modem shows I have 32 downstream channels. The lowest power rating on any of them is -2.20 and the highest is +0.10. If I'm reading that guide page correctly, that is an acceptable range. The upstream channels (6) range from +35 to +37 dBmV, and that also appears to be in the acceptable range. Downstream SNR is 38-39 dB. Upstream SNR is not reported on the Arris status page.

I don't see any clues there.

In my own battles with cable distribution, one thing I don't like is a swing on power levels.  All channels should be really close (within a dBmV or so).  It's frequency dependent.  Some say it doesn't matter.

They might be right since the frequency isn't that high, but it's critical at higher frequencies and we're all using similar phase lock loop technology regardless of frequency.  It indicates a reflection in transmission line theory, and can really screw stuff up.  That can be a dirty/oxidized connector, could be a lot of things.

If you notice a lag in "anything", log into that Arris.  You get a view of what is happening at that particular moment and varies over time.  Copy and paste the entire signal table in text form here instead of an image.  Folks here might see something you aren't seeing.  On the Xfinity side, they can see things that are not reported in that signal table too.

A test that may help:  Is this a straight coax cable run directly to your Arris or is there a splitter for a cable TV box?  Clean run directly to the modem is desirable.  If there is a splitter, can you bypass it entirely so it's just a clean run, then see if it matters with your tests? 

Post a signal table again here if you can and see if it's radically different.

@Vinndalf​  Signal table == that status page you were looking at with upstream/downstream power, SNR, errors both correctable and uncorrectables.

If you have cable TV connection and a modem, you have a splitter somewhere.  Connections on that can be a problem, and the splitter itself can have problems.  The coax cable itself can be a problem if it's frayed or kinked.  Take a look at that doc again to help you look for connector/cable/splitter/amplifier issues.  Corrosion changes everything and can happen anywhere.

All of those errors in your error log 1-3 minutes apart?  That's your connection stumbling.  You are dropping channels.  If it's constant, that is likely why you see your video connection lagging. 

It might not be your house wiring too.  It could be upstream from you and you'll need a tech to come out.  If they find splitters/amps in your house causing the problem, you pay for the visit.  If it is upstream from you, it's an Xfinity distribution problem and you won't have to pay. 

I'd look for the splitter first though, and try to bypass it for a test, and see what shape the coax and all of the connectors in your house is in, and if it's a rats nest of old cable bundled/zip tied in a pile somewhere.