I just became an xfinity customer again on 8/15/19. I bought the 400mbps extreme internet package. I had a Netgear N450 (worked flawlessly at my last location~2 years ago on a 150mbps plan) router from a previous internet plan that I was using and it was dropping internet about once an hour for 5-10 minutes and it would come back after that. I am also getting a slower speed than I figured over wifi. I get 430-460 mbps wired and the best device on wifi will only pull about 60 mbps down.
I figured the gateway might be bad, so i purchased a arris sbg6900-ac gateway to try and eliminate the problem. I was still having equivilent amount of dropped connections, so I had a technician out. He replaced the cable from the junction box on the house to the house plate and from there to the modem and tv. This cleared up my drops slightly. Still getting atleast 2-3 drops aday. I contacted Arris Tech support to see if the could assist me. They went through my down stream power and SNR readings and said they were fine. When we got to the upstream I have 4 bonded channels all of which are locked but the power levels were 40.0-41.5 on the highest channel. The Arris Tech support guy immediately said that this was the issue for dropped connections and slow wifi. I questioned that the low power level on the upstream would effect the slow downstream speed over wifi, but he insisted that what it was. So I called xfinity and explained this and a lady ran some tests and said it was ok. I tried to tell her what the Arris Tech said, but she said it's not their device and they can't see in it to test anything in the device itself. I kind of feel like Im getting the run around now. I will post a few of the event log errors I've been getting below.
Let me know if anything above needs to be clarified. Thanks for any help you can offer.
|Fri Aug 30 17:27:56 2019||Critical (3)||Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;|
|Fri Aug 30 15:53:27 2019||Critical (3)||Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;|
|Fri Aug 30 15:53:02 2019||Critical (3)||Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;|
|Fri Aug 30 06:22:38 2019||Critical (3)||Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;|
The stats are o/k. So, for a test, does a computer hardwired directly to the router / gateway device with an ethernet cable have the same problem ?
My hardwired PC drops the connection aswell as wifi devices when I get the time out issue. I get much better speed hard wired (400+ mbps) than wifi connections(40-60) though.
Even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) somewhere.
There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.
I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.
You should get a reply here in your topic. Good luck !
levim1, we're sorry to hear about the internet issues you're running into! We'd love to have the opportunity to review this further to ensure a resolution is found. Please send us a PM with your first and last name to take a look.
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I know the issue is still being looked into, but I wanted to give an update. I recently started getting a ton of corrected and uncorrcetables. as seen below.
The statuses listed show the connection state of the cable modem. They are used by your service provider to evaluate the operation of the cable modem.