Do Virgin Media cabinets have battery backup power?

I purchased a couple of UPS units after having brief power cuts, more than I was comfortable with. All my main networking gear and home equipment is on a UPS now, last night there was a power cut in my area for about 1 minute. This kept everything going so my modems, router etc all remained on. Interestingly my BT line kept its line sync, but my Virgin Media line didn't, even though the modem remained powered on throughout.

I found these events in the Hub3, 23:19:15 is the beginning of the power outage. Power came back on around 23:20.

31/05/2021 23:22:26 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
31/05/2021 23:19:21 Warning! Lost MDD Timeout;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
31/05/2021 23:19:15 Warning! RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
31/05/2021 23:19:15 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
31/05/2021 23:19:15 Warning! RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
31/05/2021 23:19:15 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
31/05/2021 23:19:15 Warning! RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;

It took a bit of time for the Virgin Media line to sync again, I had the flashing green light on my Hub3 which indicated it was updating.

It seems though that the cabinet I was connected to did not have battery backup power hence the loss of sync. The powercut radius spanned most of an outward postcode area, but I was just generally interested as this is the first real power cut since I've had UPS units running.

With the cable network being an amalgamation of lots of smaller companies from years gone by then this might not have a striaght answer.

I am not knowledgeable on this subject however I do know where I live the the basic street cabinets (amplifiers) don't have batteries within the cabinet.

The "node" cabinets where the fibre runs to do have batteries though. I believe within these cabinets the fibre is split in to the coaxial network with the coaxial side then powering the the local street coxial street cabinet amplifiers. The batteries are contained within a smaller cabinet in the middle of the two standard sized green cabinets.

I am unsure if the battery backup is just for the fibre side, or whether or not it can also power the amplifiers. I would think with the amount of homes powered from the node in a coxial system that it seems unlikely the batteries would be there to power the slave cabinet amplifiers.

Edited by gary333 (Tue 01-Jun-21 13:14:53)

Thanks for you reply. Are the node cabinets typically the larger ones that have a noticeable audible hum behind the doors? Assuming this is where the fibre runs are going into?

I believe I know the VM cabinet I'm going to (which is a standard one) and then up the next street is a larger one as you've described which I assume is serving the wider area.

I get the impression from reading more information, in most cases there aren't battery backups for VM unlike Openreach FTTC. I'm under HFC though, I don't know about FTTP. My area is quite old, this is very telling by the fact most of the pavement covers are all labelled Diamond Cable.

Where I live the older HFC ex. Yorkshire Cable network didn't have the larger cabinets they are all one size (apart from the tiny ones containing amps for the houses at the end of long runs of coax). I believe the humming would indicate it's a node.

The newer parts of the network are now all housed in "duck grey" cabinets, the nodal cabinets in new build areas are now massive and very ugly (but at least it's better than a load of street poles) .

The link gives you an insight in to how the network is setup for infil and new FTTP areas.

https://www.virginmedia.com/content/dam/virginmedia/...

Edited by gary333 (Tue 01-Jun-21 15:49:55)

Thanks I did stumble across that link a bit of time ago randomly!

All HFC around my area and the wider city really. Still can see loads Diamond Cable tee plates and a lot of the pavement covers have Diamond Cable on them, some newer ones are just CATV and there's sme NTL ones around but you can certainly see the age of some connections when they were first put in! I guess that's part of the problem like you mentioned before, with all the mergers and acquisitions, varying infrastructure inherited. Diamond Cable, Telewest, NTL, I'm sure there are others I missed in between.

No FTTP likely in our area for a while, Virgin Media have the monopoly here on anything above FTTC 80 mbps, thankfully at least DOCSIS over HFC isn't really limited despite not being FTTP. Openreach are unlikely to deploy here any time soon. I did get excited after a one.network alert showed CityFibre were in the area, turns out it was a specific fibre run for a nearby school.

But for the original question, it seems no battery backups in the standard cabs, UPS or not, you're losing sync I guess! Still keep that uptime on the modem though!

The phone cabinets, the biggest ones, have battery backup. The HFC cabinets do not. Mains power and a battery to smooth out power fluctuation but nothing that'll last long in case of loss of mains.

Do VM have batteries in cabinets?? You'll expect their CS to common sense next!