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Re: Continuous T3/T4 errors, connection dropping

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Frequent Visitor

Re: Continuous T3/T4 errors, connection dropping

@ComcastJoeTruThis seems like the same thing Ive been dealing with for months now too, same modem c7000v2, got a refubished unit in a week ago (also bought last september) through RMA before the 1 year warranty ran out. Thinking the modem itself was faulty so I was told by a tech on the phone from Comcast to rent a modem out for a month to trouble shoot..it was fine for 3 weeks. Hooked up the refurbished unit and still under 24 hrs later it was throwing the same t3/4 errors constantly and disconnecting the internet.

 

After wasting hours on the phone getting through to a Netgear tech person who actually could provide help it didnt seem to help anything, and I was told to contact comcast again to have the latest firmware applied to my mode. Even though its on the current version by comcasts site, but when I got in contact with someone on the xfi app I was told only the modem manufacturer can do this?

 

Can I get some assistance with trying to trouble shoot a possible problem on the line outside of my house/the plant node where its coming from? I had a tech come out in February to verify the connection at the poll was good, and it was..the only thing he did was put a splitter on inside the house to clean up the signal because it was too fast, something the original tech who installed the system never did.

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Expert

Re: Continuous T3/T4 errors, connection dropping


@bmac07 wrote:

Even though its on the current version by comcasts site, but when I got in contact with someone on the xfi app I was told only the modem manufacturer can do this?

 

That was incorrect. Comcast is the one who updates the firmware in straight cable modems and combination modem / router gateway devices.

 

the only thing he did was put a splitter on inside the house to clean up the signal because it was too fast, something the original tech who installed the system never did.

 

He must have meant *too strong*. It can never be too fast. Splitters have nothing directly to do with speed.


Start with the modem's signal stats. Perhaps they already are, or they are close to being out of spec and intermittently they go completely of spec. Try getting them here http://192.168.100.1 or here http://10.0.0.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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Re: Continuous T3/T4 errors, connection dropping

@EGYes sorry I meant too strong, not fast in an internet download speed. (Appologies it was months ago)

 

Here are the up and downstream pictures.

https://imgur.com/sR8xpz4

https://imgur.com/3jYziLi

 

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Expert

Re: Continuous T3/T4 errors, connection dropping

The signal stats are fine. Can you please post the error log entries in their entirety.



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Re: Continuous T3/T4 errors, connection dropping

I had been looking in previous weeks for troubleshooting and ran across the up/downstream signals etc, and they looked "within spec" so good to know that seems to be the case.

 


@EG wrote:

The signal stats are fine. Can you please post the error log entries in their entirety.


Unfortunately the log doesnt go on indefinitely so it doesnt even come close to listing all the errors today.

Time Priority Description
2020-8-25, 17:30:11Warning (5)Dynamic Range Window violation
2020-8-25, 17:10:02Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 17:09:50Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 17:09:33Warning (5)Dynamic Range Window violation
2020-8-25, 17:09:30Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 17:05:14Warning (5)Dynamic Range Window violation
2020-8-25, 17:05:03Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 17:04:30Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 17:03:54Warning (5)Dynamic Range Window violation
2020-8-25, 17:03:43Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 17:03:10Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 17:02:54Warning (5)Dynamic Range Window violation
2020-8-25, 16:59:43Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:59:31Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:59:23Warning (5)Dynamic Range Window violation
2020-8-25, 16:59:23Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:59:15Warning (5)Dynamic Range Window violation
2020-8-25, 16:59:11Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:58:55Warning (5)Dynamic Range Window violation
2020-8-25, 16:58:51Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:58:35Warning (5)Dynamic Range Window violation
2020-8-25, 16:57:23Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:56:55Warning (5)Dynamic Range Window violation
2020-8-25, 16:56:51Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:56:38Warning (5)Dynamic Range Window violation
2020-8-25, 16:37:45Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:37:37Warning (5)Dynamic Range Window violation
2020-8-25, 16:37:25Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:37:13Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:37:06Warning (5)Dynamic Range Window violation
2020-8-25, 16:37:05Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:36:57Warning (5)Dynamic Range Window violation
2020-8-25, 16:36:53Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:36:37Warning (5)Dynamic Range Window violation
2020-8-25, 16:36:33Critical (3)Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:34:39Warning (5)Dynamic Range Window violation
2020-8-25, 16:34:18Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:22:30Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.1;CM-VER=3.0;
2020-8-25, 16:21:38Notice (6)Honoring MDD; IP provisioning mode = IPv6
2020-8-25, 16:21:29Critical (3)

No Ranging Response received - T3 time-out;CM-MAC=bc:a5:11:93:b1:a4;CMTS-MAC=0c:11:67:03:1a:ad;CM-QOS=1.0;CM-VER=3.0;

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Re: Continuous T3/T4 errors, connection dropping

As a follow up point to the initial talking on the phone with a Netgear tech guy, I was instructed to change the channels on both the 2.4 and 5 ghz wireless set up page. And change the MTU size, after power cycling and waiting for an hour for it to take effect, the errors still persisted.

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Expert

Re: Continuous T3/T4 errors, connection dropping

WiFi or anything on your side of the cable modem / LAN have nothing to do with those WAN side RF signal modem errors.

 

That said. 

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 !



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Re: Continuous T3/T4 errors, connection dropping

I had hope the past day or two it didnt seem to be acting up despite the event log page being filled up, but with 2 disconnects in the last 7 minutes its back again in force sadly.

Hopefully the tech guys can figure something out.

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Expert

Re: Continuous T3/T4 errors, connection dropping

I'm going to re-escalate this.



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Re: Continuous T3/T4 errors, connection dropping

Thanks, was just remembering I think it was late last year when I had called the tech line a time or two..ended up scheduling them to call back later in the day after getting home from work. Then once I received that call the guy tried to say something along the lines of they had identified an issue "somewhere" and it was fixed. When I pressed further for information it was clear he just wanted me to acknowledge that I got his message everything was fixed and didnt want to discuss anything.

 

But obviously what ever was done there, if anything was done in the first place..never quite solved the issue as its been recurring ever since.

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Official Employee

Re: Continuous T3/T4 errors, connection dropping

Greetings, @bmac07! I appreciate you taking the time to reach out to us here on the forums. I hope you are having an amazing day! I apologize to hear of the issues you are running into with your internet connection. I know how important it is these days to make sure you have a reliable connection. I work from home myself and rely on my internet connection daily. I would like to have a further look into the signal to see if we can find anything that could be causing the issue. Can you please send me a PM with your first and last name so I may further assist you?

 

To send a private message, please click my name "ComcastMichael" then select "Send a Message" on the right side.


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