Today's conundrum is - VOIP, power cuts and UPS

[MikeSharp01]

Probably like us you have had a power cut or two over the past couple of weeks - what fun. This set me wondering because in 3 weeks we will go over to a full fibre connection to Millstone manor and our land line will switch to Voice over Internet protocol (VOIP). With the traditional land line the power for the phone - ringing and speech is derived from the exchange so they stay working in a power cut. What happens to your VOIP phone in a power cut at you home I wonder, I assume it stops operating, and then what happens to your monitored alarm if the power fails because it can no longer warn you if you are out or inform the monitoring company if an alarm is triggered. Just solved the alarm problem by getting our alarm company to switch us to radio monitoring, but what about home security and emergency calls. Do I need a  Uninterruptible Power Supply (UPS) I wonder and if so how big.

Edited February 20, 2020 by MikeSharp01
missed expansion of VOIP

[Jeremy Harris]

I run all our home network stuff from a home made UPS, for just this reason, although we've not gone as far as getting VOIP 'phones.  We used to get quite a few power cuts, and losing connectivity was a PITA, especially as a lot of them would only really be brown outs; enough to cause the modem and router to reboot, and they took far longer to come back up than the duration of the brown out.

 

It's also slightly more efficient to have everything powered from DC, I think, as the UPS power supply feeds a constant voltage to a bank of sealed lead acid batteries and then the DC from those runs the modem, router, switch etc, via PoE.

[MikeSharp01]

Hi @Jeremy Harris I found the solution - looks like this is what we will get. https://www.ispreview.co.uk/index.php/2018/05/protecting-access-to-emergency-services-in-a-broadband-voip-world.html

 

 

[PeterW]

@MikeSharp01 I’ve seen very few of those in the wild ... that article is a couple of years old and they aren’t rolling out very quick. 
 

You may just be better with a £50 UPS and the router / switch etc plugged into it. 
 

Most alarms now have GSM modules too - much easier than using wired connections. 

[MikeSharp01]

30 minutes ago, PeterW said:

Most alarms now have GSM modules too - much easier than using wired connections. 

Yes we have one on order now but I guess I will have follow @Jeremy Harris and create a UPS backed up system.

[Jeremy Harris]

The UPS could be an off the shelf one, with all the various power bricks needed plugged into it. 

 

I only opted for a DIY solution because I fitted the modem at the other end of the house from the rest of the kit, and once I'd decided that we needed battery back up it seemed to make sense to just power everything via DC from the batteries.

[MrMagic]

BT are no longer deploying battery backups for fibre deployments as pretty much everyone has a mobile now. 
 

A simple UPS with just the router and the phone should last a good hour or so. Make sure you put the phone basestation on it - the amount of times people forget that a DECT/cordless phone does not work in a power cut.