Broadband Dropouts - slow speed– SYNC Timing Errors
I’m experiencing ongoing broadband dropouts that closely resemble the issues described in the following community threads: Broadband connection keeps dropping SYNC Timing Synchronization failure – Loss of Sync My Virgin Media Hub is currently operating in modem mode, and I’m using an ASUS GT-AX11000 router to manage my home network. The dropouts affect both Wi-Fi and wired (LAN) devices, including critical appliances connected directly to the router. Symptoms include: Sudden and repeated loss of internet connectivity across all devices Devices remain connected to the router but lose access to the internet Dropouts occur randomly, sometimes multiple times per day Router logs show normal operation, suggesting the issue is upstream Given the similarity to the SYNC Timing Synchronization failures described in the community posts, I suspect this may be a signal-level or infrastructure issue. I’ve already: Verified all coaxial and Ethernet connections Updated router firmware Monitored logs and confirmed no local faults Could you please: Review the line signal levels and error logs from your end Confirm whether SYNC or RCS errors are present on the hub Advise if an engineer visit is required to inspect the line or cabinet I’d appreciate your support in resolving it promptly. Modem logs: Hub 3.0 device information The information below shows current status of this Hub 3.0. Standard specification compliant : DOCSIS 3.0 Hardware version : 10 Downstream bonded channels Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID 1 139000000 0.7 37 256 qam 1 2 147000000 0.5 38 256 qam 2 3 155000000 -0.4 37 256 qam 3 4 163000000 0 37 256 qam 4 5 171000000 -0.4 37 256 qam 5 6 179000000 -0.2 37 256 qam 6 7 187000000 -0.4 37 256 qam 7 8 195000000 -1 37 256 qam 8 9 203000000 -0.2 38 256 qam 9 10 211000000 -0.5 38 256 qam 10 11 219000000 -0.2 36 256 qam 11 12 227000000 0.2 36 256 qam 12 13 235000000 -0.2 38 256 qam 13 14 243000000 -0.5 38 256 qam 14 15 347000000 1.9 38 256 qam 27 16 355000000 2 38 256 qam 28 17 363000000 1.7 38 256 qam 29 18 371000000 1.5 38 256 qam 30 19 379000000 1.7 38 256 qam 31 20 387000000 1.7 38 256 qam 32 21 395000000 1.2 38 256 qam 34 22 403000000 1.7 38 256 qam 35 23 411000000 1.2 38 256 qam 36 24 419000000 1.2 38 256 qam 37 Downstream bonded channels Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors 1 Locked 37 37506135 813077 2 Locked 38.6 193431 36024 3 Locked 37.6 53283 2123 4 Locked 37.6 45627 1539 5 Locked 37.6 34557 1907 6 Locked 37.6 22829 1759 7 Locked 37.3 27275 803 8 Locked 37.6 18276 570 9 Locked 38.6 13821 428 10 Locked 38.6 15725 146 11 Locked 36.6 19200 171 12 Locked 36.6 19469 95 13 Locked 38.6 13178 62 14 Locked 38.9 10716 183 15 Locked 38.6 1711 74 16 Locked 38.6 1419 28 17 Locked 38.6 2184 28 18 Locked 38.9 1868 33 19 Locked 38.6 3943 42179 20 Locked 38.6 2769 993 21 Locked 38.6 2838 40 22 Locked 38.6 1801 27 23 Locked 38.6 3640 15572 24 Locked 38.6 1144 18 Upstream bonded channels Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID 1 30100000 48.5 5120 64 qam 9 2 36600034 46.8 5120 64 qam 6 3 23600000 48.3 5120 64 qam 10 4 43099997 50.3 5120 64 qam 5 5 49600000 49.8 5120 64 qam 4 Upstream bonded channels Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts 1 ATDMA 0 0 1 0 2 ATDMA 0 0 2 0 3 ATDMA 0 0 4 0 4 ATDMA 0 0 1 0 5 ATDMA 0 0 0 0 Network Log critical SYNC Timing Synchronization failure - Loss of Sync;CM-
Virgin media full outage & compensation
Firstly, the outage is still ongoing All internet & TV were lost at around 9:40pm on Saturday night. It is now Monday 1:30pm & still no internet etc. Have had text stating it is expected to be fixed TOMORROW by ~1:00pm, so that'll be a total of ~64hrs without internet or TV, can't even watch any recordings I have registered loss of service, so I guess by 9:40pm tonight I would expect this would count the start of compensation EXCEPT I've re-read the automatic compensation page online g it seems the fact that compensation is apparently if you have loss for 2 WORKING days Is this right ?, surely compensation should be if loss for 2days regardless of whether work days or weekends. People work from home probably over the weekends, so loss of internet over weekends should be compensated .. shouldn't they ???N8 - North London - Full broadband outage 11 days and counting
Just received yet another VM text kicking the can down the road another 3 days, to July 4th. But thrilled to hear that "an engineer is on their way"! (for the 10th time). I have zero confidence that it will be fixed at this time. I have zero confidence in Virgin Media, at this point. Their handling of this is beyond dreadful; it's non-existent. Yes I have reached out and lodged a complaint, but the "resolution" that I received in response is an automated copy-and-paste travesty that simply repeats the nonsense in the text messages. In the 30ish years that I have had Internet to my home, this is the very first time experiencing an outage that has lasted more than a day, anywhere. I am in London, and there are internet lines strung everywhere. Why has no technician been rerouting the line to our property after the first 24 hours? Utterly pathetic. A shame, as the service was reliable until 12:30 on Jun 20th, when it went dead. I suspect that I am now experiencing the true face of Virgin Media... which is utterly awful. Is there anyone else in the Crouch End area experiencing the same outage?Need Help Returning Equipment
I recently left Virgin Media and they sent me a box to return their equipment in. This never arrived. I am now receiving emails saying they will fine me if I don't send it back. Is there a way to get them to resend the box or to request a new label for me to send it myself, I really do not want to pay a fine when it's not even my fault. Please HelpUpstream power too high?
I've been having connection drop-out issues for the past few months (~180 reconnects within the last month according to VM, though I only saw a drop 1-2 a day for 5-90 mins at a time). I'd been mostly away from home so didn't bother about it until this week, when VM sent out an engineer to investigate (10th July). The engineer removed an old NTL attenuator/splitter, along with the splitter for the broadband and TV (as I plan to ditch the TV). He also switched out my Hub 3 for a Hub 5, which has an inline attenuator on its cable feed. Annoyingly I didn't note the full line stats before the changes, but the engineer said the downstream was reporting as -8 dBmV, and after these changes is now 0 to -5 dBmV with an SNR of 40 dB. I'm still having drop-outs (and T2 and T3 timeouts), though less frequent (1 time a day for 1-5 mins at a time), and from doing some research I suspect my upstream power is still too high. It's currently sitting at 52 dBmV, but I've seen it get as high as 59 dBmV immediately after the modem reconnected (it drops back down to 52 dBmV over a span of ~20 mins once the connection is back up). I just wanted to confirm my understanding is correct before requesting another engineer visit to correct the upstream power. I tried to add the full line stats and log into this post, but the forums report "Your post contains invalid HTML." if I do... that used to work.Intermittent connection issues
For the last couple of weeks, few times per day my internet completely drops for short time (usually less than 1 minute), and after that all is back to normal. This happens at completely random times - there are days when it doesn't happen at all, and other days when it happens several times. Once that happens VM service status page shows "Intermittent signal in your area", then it changes to "You need to book an engineer", and then it's back to "No broadband issues" (until next disconnect). The engineer came last week, he checked the wiring, signal, etc., and didn't find any issues on my side. He also replaced my Hub 3 with new Hub 5. Unfortunately the issue keeps happening after that. Here you can see how these drops look: Every time when these issues happen, the network log in the Hub shows multiple 'critical' entries such as: No Ranging Response received - T3 time-out 16 consecutive T3 timeouts while trying to range on upstream channel Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out SYNC Timing Synchronisation failure - Loss of Sync Could someone from VM have a look and help please? 3.0 Downstream channels Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID 1 330000000 6.4 41 QAM 256 25 2 138000000 4.7 40 QAM 256 1 3 146000000 4.9 40 QAM 256 2 4 154000000 4.9 40 QAM 256 3 5 162000000 4.9 40 QAM 256 4 6 170000000 4.9 40 QAM 256 5 7 178000000 5 40 QAM 256 6 8 186000000 5.1 40 QAM 256 7 9 194000000 5.3 40 QAM 256 8 10 202000000 5.2 40 QAM 256 9 11 210000000 5.3 40 QAM 256 10 12 218000000 5.4 40 QAM 256 11 13 226000000 5.4 40 QAM 256 12 14 234000000 5.5 40 QAM 256 13 15 242000000 5.6 41 QAM 256 14 16 250000000 5.6 41 QAM 256 15 17 258000000 5.7 41 QAM 256 16 18 266000000 5.6 41 QAM 256 17 19 274000000 5.8 41 QAM 256 18 20 282000000 5.9 41 QAM 256 19 21 290000000 6.2 41 QAM 256 20 22 298000000 6.3 41 QAM 256 21 23 306000000 6.3 41 QAM 256 22 24 314000000 6.4 41 QAM 256 23 25 322000000 6.4 41 QAM 256 24 26 338000000 6.5 40 QAM 256 26 27 346000000 6.7 41 QAM 256 27 28 354000000 6.7 41 QAM 256 28 29 362000000 6.9 41 QAM 256 29 30 370000000 6.9 41 QAM 256 30 31 378000000 7.1 41 QAM 256 31 3.0 Downstream channels Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors 1 Locked 41 2166 7079 2 Locked 40 4100 9616 3 Locked 40 4414 15176 4 Locked 40 8311 44157 5 Locked 40 8257 42752 6 Locked 40 8282 46018 7 Locked 40 3734 9961 8 Locked 40 4150 15136 9 Locked 40 2425 6338 10 Locked 40 5829 26867 11 Locked 40 2236 5521 12 Locked 40 1792 4249 13 Locked 40 2056 4722 14 Locked 40 7266 38180 15 Locked 41 2715 12483 16 Locked 41 2280 11454 17 Locked 41 2364 6014 18 Locked 41 2569 9438 19 Locked 41 1924 6029 20 Locked 41 3257 15859 21 Locked 41 1596 4954 22 Locked 41 1679 4609 23 Locked 41 2012 5221 24 Locked 41 3982 22531 25 Locked 41 1646 4652 26 Locked 40 1828 7782 27 Locked 41 1880 7241 28 Locked 41 1724 6518 29 Locked 41 2106 10214 30 Locked 41 1932 8377 31 Locked 41 1543 5268 3.1 Downstream channels Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz) 33 92 4K 1800 QAM 4096 1128 3.1 Downstream channels Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile) 33 Locked 41 6.3 238950482 76 3.0 Upstream channels Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID 0 49600000 51.5 5120 QAM 64 1 1 43100000 51.5 5120 QAM 64 2 2 36600000 52 5120 QAM 64 3 3 30100000 52.3 5120 QAM 64 4 4 23600000 52.8 5120 QAM 64 9 3.0 Upstream channels Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts 0 ATDMA 0 46 0 0 1 ATDMA 0 46 0 0 2 ATDMA 0 46 1 0 3 ATDMA 0 46 0 0 4 ATDMA 0 46 0 0 3.1 Upstream channels Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation 12 10.4 46.5 2K QAM 256 3.1 Upstream channels Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts 12 OFDMA 208 74000000 0 0Internet connection drops at random
We have a Hitron CGNV4 router running VM business—our home wifi is included in rent, therefore it's all under the letting agent's details. Over the past roughly two weeks we have been getting intermittent connection loss, usually for around a minute maximum, affecting both wifi and ethernet connections. It reconnects on its own but the disruption is long enough to disconnect us from calls and games. Some days it is pretty frequent, with 2-3 disruptions an hour, while other days we only experience one or two all day. I've done a power cycle on the router which has not fixed the issue. I've not yet tried a factory reset but having looked at some other people with similar issues that doesn't seem to have fixed it for them. I've also tried calling the business helpline but not been able to get through security (as it's under the agent's info, and despite me asking them they've not given me the account details I need). Would appreciate any advice on this to know if I could fix it myself or if we need to get a tech in. Logs No. Time Type Priority Event 1 06/23/25 16:14:20 90000000 warning MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 2 06/23/25 16:14:23 73040100 notice TLV-11 - unrecognized OID;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 3 06/25/25 16:19:49 82000200 critical No Ranging Response received - T3 time-out;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 4 06/26/25 17:55:02 68010300 error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 5 06/26/25 17:55:02 68010600 notice DHCP Renew - lease parameters tftp file-cmbus-vmdg515-bbt071-b.cm modified;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 6 06/26/25 23:56:11 82000200 critical No Ranging Response received - T3 time-out;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 7 06/28/25 20:46:44 90000000 warning MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 8 06/28/25 20:46:48 73040100 notice TLV-11 - unrecognized OID;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 9 06/29/25 23:40:10 82000200 critical No Ranging Response received - T3 time-out;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 10 06/30/25 05:54:54 68010300 error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 11 06/30/25 05:54:54 68010600 notice DHCP Renew - lease parameters tftp file-cmbus-vmdg515-bbt071-b.cm modified;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 12 07/02/25 16:01:47 82000200 critical No Ranging Response received - T3 time-out;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 13 07/02/25 18:07:23 90000000 warning MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 14 07/02/25 18:07:25 73040100 notice TLV-11 - unrecognized OID;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 15 07/03/25 17:54:50 68010300 error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 16 07/03/25 17:54:50 68010600 notice DHCP Renew - lease parameters tftp file-cmbus-vmdg515-bbt071-b.cm modified;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 17 07/06/25 22:03:20 82000200 critical No Ranging Response received - T3 time-out;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 18 07/07/25 05:54:50 68010300 error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 19 07/07/25 05:54:50 68010600 notice DHCP Renew - lease parameters tftp file-cmbus-vmdg515-bbt071-b.cm modified;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; 20 07/08/25 06:37:37 82000200 critical No Ranging Response received - T3 time-out;CM-MAC=74:9b:e8:9d:dc:40;CMTS-MAC=58:ac:78:69:ee:b1;CM-QOS=1.1;CM-VER=3.0; Downstream overview Port Frequency (Hz) Modulation Power (dBmV) SNR (dB) Channel 1 203000000 256QAM -0.400 40.946 9 2 139000000 256QAM -0.900 40.366 1 3 147000000 256QAM -0.900 40.946 2 4 155000000 256QAM -0.900 40.946 3 5 163000000 256QAM -0.700 40.366 4 6 171000000 256QAM -0.600 40.366 5 7 179000000 256QAM -0.500 40.366 6 8 187000000 256QAM -0.400 40.946 7 9 195000000 256QAM -0.500 40.946 8 10 227000000 256QAM -0.500 40.366 12 11 243000000 256QAM -0.700 40.366 14 12 251000000 256QAM -1.000 40.946 15 13 259000000 256QAM -0.800 40.366 16 14 267000000 256QAM -0.700 40.946 17 15 275000000 256QAM -0.600 40.366 18 16 283000000 256QAM -0.600 40.946 19 17 291000000 256QAM -0.500 40.366 20 18 339000000 256QAM 0.500 40.366 26 19 347000000 256QAM 0.300 40.366 27 20 355000000 256QAM 0.100 40.946 28 21 363000000 256QAM 0.200 40.366 29 22 371000000 256QAM 0.200 40.366 30 23 379000000 256QAM 0.400 40.366 31 24 387000000 256QAM 0.600 40.946 32 Upstream overview Port Frequency (Hz) BandWidth Modulation Power (dBmV) Channel 1 43100000 6400000 ATDMA 51.000 2 2 30100019 6400000 ATDMA 52.000 4 3 36600000 6400000 ATDMA 51.000 3 4 49600000 6400000 ATDMA 51.000 1Internet keeps dropping off for a minute or so
Hello! My internet keeps dropping off throughout the day for a minute or so, both wired and wireless. Tried support and got nowhere. The issue only appeared or started occurring after I upgraded my internet package and got the superhub 5. Support noted that i have had 72 disconnects in the month of june but have been unable to resolve my very frustrating issue. Here are the info from the network log on my router. Mod Edit: Personal information removed 03-07-2025 16:57:54 notice 03-07-2025 16:54:06 notice 03-07-2025 09:12:35 error 03-07-2025 02:37:41 critical 02-07-2025 21:00:50 notice 02-07-2025 20:58:34 notice 02-07-2025 20:27:10 notice 02-07-2025 20:20:27 notice 02-07-2025 19:31:58 notice 02-07-2025 19:29:09 notice 02-07-2025 19:19:49 notice 02-07-2025 19:11:39 notice 02-07-2025 19:09:32 notice 02-07-2025 19:08:21 notice 02-07-2025 19:06:22 notice 02-07-2025 19:01:56 notice 02-07-2025 19:01:18 notice 02-07-2025 19:00:48 notice 02-07-2025 18:58:01 notice 02-07-2025 18:40:15 notice 02-07-2025 18:04:36 notice 02-07-2025 18:03:21 notice 02-07-2025 18:01:14 notice 02-07-2025 18:00:19 notice 02-07-2025 04:48:28 notice 02-07-2025 04:44:36 notice 02-07-2025 04:43:27 notice 02-07-2025 04:41:39 notice 02-07-2025 04:38:32 notice 02-07-2025 04:34:29 notice 02-07-2025 04:24:26 notice 02-07-2025 04:12:03 notice any other information needed please let me know and hopefully i can get my internet working properly again. Thanks!Internet stops working once a day requiring a router reboot
Hi, I recently upgraded from volt500 to volt 1gig, which needed a modem change from hub3 to hub5. I use it in modem mode with my own router. Once a day now, the internet completely stops working, and I need to reboot the router by unplugging and replugging. After doing some searching, my 3.1 downstream channel is extremely weak. Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile) 159 Locked 32 -15.7 41903970 12674230 Can someone look into this?
