It's almost never the modem. Support techs always blame the modem and I think that costs Cox and their support a lot of credibility. I wish they would change that policy but I'm just a customer so what can I do?
I'm still learning about OFDM, but what I can tell you is that Event Type Code 16 means "Downstream OFDM profile failure" which is caused by "FEC errors were over the limit on one of the assigned downstream OFDM profiles of a channel" and Event Type Code 24 means "OFDM profile recovery" which is caused by "FEC recovery on OFDM profile". FEC means "forward error correction" and that refers to correctable codewords.
From what I understand, you want to see a lot of correctable errors on the OFDM channel because that means it's running at its maximum possible speed. When you start seeing uncorrectable errors, that's when you should worry. I think the messages you're seeing are just the modem shuffling around OFDM profiles for maximum performance.
Your downstream signals and error rates look excellent so I would suggest looking for other errors in your modem log related to upstream connections such as T3 timeouts or Dynamic Range Window violations. The OFDM CM-STATUS messages might make it hard to find those errors but keep refreshing the page to see what you can catch.
Now that you mention it, I did see some dynamic range window violations upon startup of the modem. However I have never seen them pop up when my internet drops. However the CM-Status messages always coincide with my interruptions so I thought that might be the issue. Here is a screenshot of a modem boot I had.https://imgur.com/a/eLsCkbH
Maybe there is some type of disruption associated with changing OFDM profiles. I don't know enough about how it works to say for sure. Hopefully someone who knows more than me can answer that. It does seem like it's reassigning your OFDM profiles a lot. I only get this type of message anywhere from every few hours to every few days.
I think the DRW violations at startup are normal. The only thing I've noticed there is that when my connection is working, the DRW messages are the ones about "6dB below" whereas when I'm having problems I see the "exceeds value" messages.
Thank you for your help Dave. I found a old post a while back when someone had almost the same issue with cox. They had to get a higher level tech out and monitor the line.
Do you have any idea how as a customer we can elevate the issue so that they send an advanced tech out to inspect the signal at the node? So far the only thing I can request is to get a regular tech out and they do nothing except blame my modem.
