Question Losing internet connection throughout the day ?

[drummerJ99]

Have had xfinity for about 5 years with no issues, other than price I've really had no complaints about service. However due to that price and price of everything else, we've had to recently drop our speeds to save some money. I don’t think that’s our issue but figured I’d mention it.

We started with a NetGear CM500 modem (6 years old) and NetGear AC1600 (just over a year old) router, after having issues we tried another modem. A brand new Arris Surfboard 6183.

Finally got a tech out yesterday. They changed a few coxial connections, grounded the line and removed some kind of "simulator" that was on the modem from initial install. He tested the line outside and at the modem. He said both were perfect. But he said his one area of concern is that both my modems are Docsis 3.0 and he's heard issues of connection problems with those since they've upgraded lines and recommend a Docsis 3.1.

So after all that after he left I still had issues. I checked out the event log of the new modem and all these have happened since tech was out. So was he right about the 3.0 and 3.1 issues? I'm about to the point of just renting a modem from I don't have to deal with this anymore, which I'm sure is what they want. LOL

Here's the log list of the first incident after he left.
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;Wed Jul 03 13:03:44 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 13:03:44 2024 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 13:03:44 2024 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 13:04:02 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 13:08:22 2024 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:09:12 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:09:12 2024 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:09:12 2024 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:09:40 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:09:40 2024 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:09:40 2024 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:09:47 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Wed Jul 03 14:14:07 2024 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.1;CM-VER=3.0;Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6Time Not Established Warning (5) ToD request sent - No Response received;CM-MAC=24:94:cb:ff:ce:8c;CMTS-MAC=00:01:5c:88:52:4c;CM-QOS=1.0;CM-VER=3.0;

 

[bill001g]

It doesn't really matter if it is docsis 3.0 or docsis 3.1....unless the ISP stops supporting 3.0 completely. The main difference is you can not buy the very fast plans unless you also have a docsis 3.1. The ISP is unlikely to drop support because they know that most the people that have older modem also are running the lower cost plans and might not be willing to buy a new modem or pay extra each month for rental. They could lose a lot of customers especially if there is another isp using fiber in the same neighborhood.

Pretty much those unicast maintenance messages are similar to a ping command from your pc. A few here and there means nothing but if you get enough the modem will drop the connection and restart. You also see a bunch of garbage like this when the modem first connects so be sure it is something happening later.

Not sure why you say "modems" do you somehow have 2 activated at the same time or is one a spare.

What you can do is do what the ISP did. There should be a screen that shows the signal levels and data loss rates. You can compare these levels with the recommended ones. A common thing to see when you are getting those timeout messages is your upload level is far too high. It means the ISP equipment has told your modem to transmit at higher levels because it can not hear it.

In most cases this is a cabling problem but they just checked it. It would be unlikely to be a modem problem if it happens on multiple modems.

 

[drummerJ99]

It doesn't really matter if it is docsis 3.0 or docsis 3.1....unless the ISP stops supporting 3.0 completely. The main difference is you can not buy the very fast plans unless you also have a docsis 3.1. The ISP is unlikely to drop support because they know that most the people that have older modem also are running the lower cost plans and might not be willing to buy a new modem or pay extra each month for rental. They could lose a lot of customers especially if there is another isp using fiber in the same neighborhood.

Pretty much those unicast maintenance messages are similar to a ping command from your pc. A few here and there means nothing but if you get enough the modem will drop the connection and restart. You also see a bunch of garbage like this when the modem first connects so be sure it is something happening later.

Not sure why you say "modems" do you somehow have 2 activated at the same time or is one a spare.

What you can do is do what the ISP did. There should be a screen that shows the signal levels and data loss rates. You can compare these levels with the recommended ones. A common thing to see when you are getting those timeout messages is your upload level is far too high. It means the ISP equipment has told your modem to transmit at higher levels because it can not hear it.

In most cases this is a cabling problem but they just checked it. It would be unlikely to be a modem problem if it happens on multiple modems.

My modems was in reference to the original NetGear CM500 that I was using when the issues started and the new Arris Surfboard 6183 that was just purchased this week. I'm having the same issue with both my old and my new.

 

[bill001g]

The arris has the signal level sceens and packet loss screens. You need to check the levels and make sure you have very low rates of uncorrectable errors...ie loss

The IP should be 192.168.100.1