T3 time out causing outages

Question

Hi,In the last few weeks I've noticed short outages which look to be caused by T3 timeouts, they seem to be at random but cause loss of service when in the middle of doing something (games, voice chat, work, streaming, etc). I think it might be related to noise on upstream as the logs show the channels switching back and forth although downstream error count is huge. I've tried the usual of checking connections and leaving the Hub5 powered off for a while but it keeps coming back.Logs etc below &amp; attached, although they don't go back very far. Looks like T3 issue has happened twice since the hub was rebooted under 2 days ago.Thanks,PeterTimePriorityDescription29-10-2025 16:26:59criticalNo Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;29-10-2025 16:26:39warningMDD message timeout;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;29-10-2025 06:55:43errorDHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;28-10-2025 02:44:08criticalReceived Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;27-10-2025 21:36:55noticeREGISTRATION COMPLETE - Waiting for Operational status27-10-2025 21:36:44noticeDS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;27-10-2025 21:36:41warningDHCP WARNING - Non-critical field invalid in response ;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;27-10-2025 21:36:39noticeHonoring MDD; IP provisioning mode = IPv427-10-2025 21:36:36criticalNo Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;27-10-2025 21:36:31criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;27-10-2025 21:36:30criticalCable Modem Reboot because of - HW or Power-On Reset27-10-2025 20:47:41criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;27-10-2025 20:47:41critical16 consecutive T3 timeouts while trying to range on upstream channel 8;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;27-10-2025 20:47:35criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;27-10-2025 11:23:46criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;27-10-2025 11:23:45criticalCable Modem Reboot because of - Reboot Timezone Change27-10-2025 11:21:20criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;27-10-2025 11:21:19criticalCable Modem Reboot because of - HW or Power-On Reset24-10-2025 13:01:55critical16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:01:55criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:01:49criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:01:25criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:01:25critical16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:01:01criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:57criticalNo Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:56critical16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:56criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:50criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:44criticalNo Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:42criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:42critical16 consecutive T3 timeouts while trying to range on upstream channel 4;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;24-10-2025 13:00:37criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;&nbsp;

Client62 · Answer

I find the Log tab to be far less informative than the Downstream & Upstream signal levels & error counts.

Way down in the last image, the 3.1 Download : RxMER DATA (dB) of 0 does not look right, but that could be a VM Hub issue i.e. a data display error.

The number of 3.0 Upstream T3 errors are very low, especially if those are the total for several days.

Tudor · Answer

Check with Area faults on 0800 561 0061 If you have a VM landline 150 this goes down to post code level. You could also try the web service status page, but this is not recommended as it only covers issues that affect a very large number of customers.

VM will not dispatch any technicians while an area fault exists.

If no area faults found:

The primary place to report faults or for service requests is Customer Services on 0345 454 1111/150 if you have a VM landline or wait two or three days for a VM staff member to get to your post. This board is not a fault reporting system.

Forum Discussion

T3 time out causing outages

2 Replies

Related Content

Coax signal is causing bad pixelation

Intermittent broadband outages

Service outage

Area 30 Outage

HDMI Connected to External Monitor to My Laptop Causes Internet to Disconnect.

Time	Priority	Description
29-10-2025 16:26:59	critical	No Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
29-10-2025 16:26:39	warning	MDD message timeout;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
29-10-2025 06:55:43	error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
28-10-2025 02:44:08	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 21:36:55	notice	REGISTRATION COMPLETE - Waiting for Operational status
27-10-2025 21:36:44	notice	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 21:36:41	warning	DHCP WARNING - Non-critical field invalid in response ;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 21:36:39	notice	Honoring MDD; IP provisioning mode = IPv4
27-10-2025 21:36:36	critical	No Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 21:36:31	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 21:36:30	critical	Cable Modem Reboot because of - HW or Power-On Reset
27-10-2025 20:47:41	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 20:47:41	critical	16 consecutive T3 timeouts while trying to range on upstream channel 8;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 20:47:35	critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 11:23:46	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 11:23:45	critical	Cable Modem Reboot because of - Reboot Timezone Change
27-10-2025 11:21:20	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
27-10-2025 11:21:19	critical	Cable Modem Reboot because of - HW or Power-On Reset
24-10-2025 13:01:55	critical	16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:01:55	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:01:49	critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:01:25	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:01:25	critical	16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:01:01	critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:57	critical	No Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:56	critical	16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:56	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:50	critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:44	critical	No Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:42	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:42	critical	16 consecutive T3 timeouts while trying to range on upstream channel 4;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;
24-10-2025 13:00:37	critical	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=00:01:5c:85:86:54;CM-QOS=1.1;CM-VER=3.1;