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Critical Error's in the Hub 5 log

On our wavelength

Hi folks,

I am getting some critical errors in the log of my Hub 5, do you think that these could impact performance of our 1Gb broadband?

5-06-2023 23:00:46critical16 consecutive T3 timeouts while trying to range on upstream channel 8;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-06-2023 23:00:46criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-06-2023 22:59:38criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

Any help would greatly be appreciated.






Here are some images for you -


All the images have the dates in them.

You will notice that latency (yellow line up from bottom) is very random on the link and sometimes we have the situation where we have drops (red line from top down). 

This is monitoring the link 24 hours a day.

From the tools that I run from home I see most of the variation come from the Cosham IP node back into the core network. I know that you have installed another node in Cosham which has improved the situation but as you can see from the image from 010723 there was a major loss (100% drops) of traffic to my CM. Also during 010723 we started yet again to see the average latency increase again. Also today we are seeing regular drops, not that many yet but they do appear to be increasing.

 Downstream of Cosham and your core network I assume you link into London LINX to interchange data with other suppliers.  Is this correct?

Hope this gives you enough information.


Infinidim (John)


You also had these critical errors on 010723 as well after we had all the drops on our link.

01-07-2023 06:17:10criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
01-07-2023 06:16:58criticalCable Modem Reboot via RG reboot command
01-07-2023 06:14:50criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

Not good.


Infinidim (John)

Very Insightful Person
Very Insightful Person

Hi John,

Sorry but you need to repost the BQM's - they need the IP address removing before they will be accepted.

I don't work for Virgin Media.
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Here are the images without my IP address in them. 

  • b986df0328e5861066ed8b390c52a7b86d1d9023-29-06-2023.png





Thank you for sending this over I appreciate it.

I am going to send you a PM so we can look into this in more depth, please look out for my PM.

It will be in your inbox. Cheers 

Matt - Forum Team

New around here?

On our wavelength

I have been providing information about the performance of our Virgin Media broadband and nobody from the forum team has come back to me via private message in the last three weeks.

It is as if Virgin Media is no longer interested in me being one of it's customers.
In the last two weeks I have had T3 errors on my broadband -

3.0 Upstream channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
0 ATDMA 0 0 3 0
1 ATDMA 0 0 2 0
2 ATDMA 0 0 2 0
3 ATDMA 0 0 2 0
4 ATDMA 0 0 2 0

Here is a snapshot of the errors.

I have also been having latency issues as well.

From 10/10/23From 10/10/23

here is an image of the issue.

Will someone come back to me about these issues

Infinidim (John)