[chbot] Recommendations for fibre in CHCH

Helmut Walle helmut.walle at gmail.com
Thu Mar 4 22:40:21 GMT 2021

Sorry, Mark - I did not respond to the dial tone question initially, because you had already
mentioned that you would need backup power for your router to keep it going, and that the rest
of the system would need to have a backup power supply, too - so it looked like an acknowledged
and well understood issue.

But actually there may be a little bit more to it... as per Charles's comment below the dial
tone itself is generated by the router if the router does have analogue / POTS telephony ports
(many or probably most do, but if it's important check what you get or are buying). If it does
not you can still use a VoIP app on any terminal equipment (Mobile phone, tablet, laptop,
desktop PC) connected to a VoIP service via any Internet connection (you can for example run a
VoIP call using a mobile phone over a 4G/LTE based Internet connection just fine, even though
that is not the "standard" way of making voice calls on 4G). If you need to be able to connect
an old-style analogue phone you will either need a router with support for analogue phones, or
you can add an Analogue Telephone Adapter (ATA) that provides both the physical interface and
all the protocols required for VoIP calling. Or you can use a VoIP phone set to plug into your
LAN. Obviously any and all of these devices needs backup power.

Now there is a further point to consider: the fibre does not plug into the router. The fibre
will per definition only reach to the optical network termination (ONT). In principle this could
be anywhere, but in practice it will probably end up being either close to where the line enters
the house, or if there is a telecommunications cabinet (probably the case in all recent builds)
where all the various networs cables are ending (TV, LAN, phone, ...) it will be there. The ONT,
true to its name, terminates the optical network connection at the customer premises end, and it
provides a range of demultiplexing / multiplexing services and respective physical ports. It
will at least have an Ethernet port (should be Gbps), because that is needed to connect the
router, and it may well have analogue telephony ports, too. The ONT that came with my "default"
fibre install has 4 x Eth and 2 x Phone. Only one of my Eth ports is used to connect the router.
But I am not using the phone ports on the ONT at all, because the ONT is in the telecoms cabinet
in the garage, whereas the router is in the lounge, and that is where I need the phone. The
"default" router that I got also has two analogue phone ports...

Soooo - for me to have a dial tone during a mains outage, I would need backup power for both ONT
and router. And that is in addition to backup power for the phone itself, because, although it
is an "analogue" phone it actually is a wireless type that obviously also needs a power supply.
Now where I wrote backup power, none of these devices really need an AC mains supply, as they
all happen to come with a plug pack anyway... So a much simpler "UPS" consisting just of a
battery and a trickle / maintenance charger would be quite sufficient.

With all of that hassle in mind, and mains outages being quite rare here, a mobile phone may be
the better option for emergency calling.

Further to the technical discussion above, there are also regulations in place to set out
requirements for emergency calling services. These also include requirements for making
customers aware of the possibility of loss of certain services in the event of a power outage.
If you are interested in that the NZ Telecommunications Forum may be a starting point,
specifically the "Broadband Product Disclosure Code" and the "Emergency Voice Calling Services


I am not too familiar with the higher-level regulatory framework and its drivers, but the
Telecommunications Act could provide relevant information. Schedule 2A of the Act about the
Copper Withdrawal Code may be relevant, too. The finalised Copper Withdrawal Code itself has
just been published recently

Kind regards,


On 05/03/2021 08:32, Charles Manning wrote:
> Unlike with ADSL, you will not get a dial tone in a power outage.  There is no ring voltage over
> fibre because it is non-conductive. That has to be recreated in-house by the fibre modem thingy
> (I assure you that is the correct technical term :-)). If that is not getting power then no dial
> tone. If you have a UPS then you should be good.
> -- Charles

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