Two networks/ONTs in a single house... problems?

Hi all,

I have a quick question please about a situation where a single house has access to two separate FTTP networks, involving two separate fibre cables and ONTs in the property (eg. one from Openreach, one from Cityfibre).

If I choose an ISP such as Zen Internet / Gigabit etc. who operate on both networks, how will they know which network to use and which ONT I should plug into? Could this cause confusion and potential problems when changing ISP?

Thanks in advance for your help!

It doesn't really matter whether the ONTs are already installed or not. If your property is passed by networks A and B, then your service provider will choose to deliver using network A or network B, and if there's no existing ONT then one will be installed.

Your service provider will most definitely know which network/ONT you will use, because they have to place a wholesale order with a specific network. In other words, they make an explicit choice which network to use to serve your property.

In the case of a property covered by both Openreach and Cityfibre, *and* the ISP you've chosen makes use of both networks in your area, then for commercial reasons typically they will set up their systems to choose the Cityfibre one (it's cheaper at wholesale, so it makes them more money; and you benefit from higher upload speeds, and in some cases lower retail pricing). But they might not, e.g. if they also have contractual quotas they have to fulfil with Openreach.

The problems with changing ISP will come when your current service is on network A, and your new service is on network B. You may find that the service on network A is not terminated automatically. (However if it involves the porting of a phone number, it will probably work out fine).

This sort of problem should go away in the next year or so, when the new cross-network migration procedures have been rolled out.

It's been like this for many years, when moving between Openreach and Virgin Media networks, but the arrival of altnets has increased the number of players dramatically.

Many thanks for the quick and detailed reply. Can I also ask please:

1) If, as you say, the service on network A is not terminated automatically, is this actually a problem if I'm no longer paying for it and am only plugged into network B?

2) In theory, say the Cityfibre network was sold/consolidated into Openreach in the future. So I had 2 x ONTs both on Openreach's network but to the same address. Would this cause issues?

Thanks again!

1. If the service is present in the property, say on an existing ONT, but you’re not actually paying to receive a service then it’s completely benign. Like a master socket with a phone connected to it that you no longer have an active service - it’s just there but you can’t use it until you have it activated.

2. Wouldn’t be an issue. This already happens in a some cases where a second FTTP service is ordered to the same address.

In reply to a post by Daveston:

Many thanks for the quick and detailed reply. Can I also ask please:

1) If, as you say, the service on network A is not terminated automatically, is this actually a problem if I'm no longer paying for it and am only plugged into network B?

The problem is that you *will* still be paying for the service on network A, until you cease it.

Until the new cross-network migration system is up and running, your new service on network B is a second independent line into the property, not a migration of the service which was on network A.

When you instruct ISP A to cease the service, they can disable it remotely. They do not need to visit the property or touch the network. The ONT will still be drawing a tiny amount of power, but you can unplug it.

In reply to a post by Daveston:

2) In theory, say the Cityfibre network was sold/consolidated into Openreach in the future. So I had 2 x ONTs both on Openreach's network but to the same address. Would this cause issues?

This is very, very, very unlikely to happen.

Openreach has nothing to gain from buying a network which mostly overlaps with what it has already built or is building, and is either built to completely different technical specification (microducts) or uses Openreach's existing duct and pole infrastructure already.

Furthermore, the main commercial value in Cityfibre's network is that it is unregulated, i.e. it can cherry pick areas which are cheap to build, and undercut Openreach pricing in those areas. If it were merged, it would lose that benefit.

A related question might be: what if one company ends up owning both Virgin Media and Cityfibre? In that case, the merging of the networks would be its own headache to deal with, and how they supply service to any particular property is also up to them. At delivery time, they would instruct their engineers accordingly.

Edited by candlerb (Tue 24-May-22 09:38:34)

In reply to a post by candlerb:

A related question might be: what if one company ends up owning both Virgin Media and Cityfibre? In that case, the merging of the networks would be its own headache to deal with

I suspect that would depend if cable TV is still important, or if TV moves to a fully IP based service, and if DOCSIS (RFOG) has any benefits over GPON. But that is crazy talk

If you're looking at Zen and you have Cityfibre and Openreach available its highly likely they will connect you through Cityfibre as Zen have signed an exclusive volume commitment with Cityfibre.

Many thanks again for all the advice.

One quick follow-up please: is the problem therefore in theory only that you will need to absolutely ensure that Network A terminate the connection (and you stop paying for it) at a similar time to starting with Network B? So it's just a case of ensuring they don't just migrate the service and actually switch it off completely?

In reply to a post by Daveston:

One quick follow-up please: is the problem therefore in theory only that you will need to absolutely ensure that Network A terminate the connection (and you stop paying for it) at a similar time to starting with Network B?

Yes. But because there's no coordination between the two, there's a risk that if you arrange a cease for service A on a given date, and then the installation of service B slips, you will be without service entirely.

Therefore I'd recommend you don't request ISP A cease their service until *after* service B is installed and working. And that means you may be paying for a period of overlap, or possibly a termination notice period (even if out of contract).

In reply to a post by Daveston:

So it's just a case of ensuring they don't just migrate the service and actually switch it off completely?

They're not actually migrating a service at all. ISP B is providing you with a new service, and independently of this, you request the old service to be switched off by ISP A. The point is, today it's *you* who are responsible for doing the latter part, not ISP B.

There is another scenario, where it's possible that the ISP who uses both networks would migrate you from network A to network B (e.g. if you are an existing Zen customer via Openreach, and Cityfibre later becomes available in your area, Zen could choose to move you across). Typically this would only be done at the time you recontract. If it happens, they will talk you through whatever you need to do.