How the nbn™ network works

The nbn™ network is a crucial piece of national infrastructure – but also a very complicated one. So here’s our easy-to-understand guide to how all the pieces of the jigsaw fit together and we deliver access to great broadband to Australians.

The nbn™ network is a crucial piece of national infrastructure – but also a very complicated one. So here’s our easy-to-understand guide to how all the pieces of the jigsaw fit together and we deliver access to great broadband to Australians.

Getting to the Point of Interconnection

A crucial part of the nbn™ network are the 121 Points of Interconnection (POIs) – typically located at telephone exchanges – which is where retailers such as Telstra, Optus and TPG plug their own network into the nbn™ network.

The networks that telecom retailers use to plug into the nbn™ network are called ‘backhaul’ networks.

Whilst some retailers have their own backhaul networks that plug into the nbn™ network POIs, other retailers have to lease backhaul capacity from other providers.

Backhaul is a crucial part of the delivery chain for services over the nbn™ network - if retailers cannot get all of its traffic to or from the POI properly, end-user speeds will be affected regardless of the technology end-users are on.

Buying enough megabits….or water

nbn generates revenues by selling capacity – what we call a Connectivity Virtual Circuit (CVC) - on the nbn™ network to retailers who then sell this on to end-users as part of a retail broadband package.

This might sound complicated but it’s really not.

Let’s say that nbn was selling water rather than data and a retailer had 100 end-users that it needed to supply water to.

It would be wasteful – and very expensive – for the retailer to buy 5,000 litres of water an hour in order to make sure that all 100 end-users could access 50 litres of water per hour at any time of the day or night.

Instead, it is more practical for the retailer to work out how much they need to buy so that they are not wasting water in the quiet usage period.

However, retailers also need to have enough water available to meet demand when everybody is taking their morning or evening shower.

If the retailer does not get their sums right and doesn’t have enough water flowing through the pipes to meet peak-usage, there will be a lot of people standing under a meagre dribble of water from their showers rather than the thundering torrent they were hoping for.

This is quite a lot like how the nbn™ network works as well.

It really doesn’t matter if an end-user has a Fixed-Broadband or Fixed-Wireless connection, if there are too many end-users competing for not quite enough bandwidth, then their experience on the nbn™ network will not be great.

From the POI to the neighbourhood….and back again

Once the data leaves the POI, it is travelling on the nbn™ network via our distribution fibre which is connected to our Fibre Distribution Hub (for FTTP), Cabinets (for FTTN), Nodes (for HFC) or Fixed-Wireless towers.

These distribution links will vary in how much capacity they have depending on the size of and demand in the area to be served.

For example, with FTTN Cabinets, which typically serve around 200 end-users, there is between 1-2Gbps of capacity in place and nbn continually monitors this to ensure there sufficient capacity in place.

If we do find our distribution links are getting busier they are upgraded well ahead of becoming congested. 

The road home

The final stretch of the network runs from the neighbourhood Hub/Cabinet/Node/Tower into the end-user premise via either fibre, copper, co-axial or wireless and then data travels from the end-user modem – usually via wi-fi – to any of the multiple devices that our end-users have connected to the nbn™ network.

So, that’s how the nbn™ network works, there are multiple players involved in making sure end-users have a great user experience.

Both nbn and our retailer partners are always looking to learn how we can deliver the best possible experience.

Your experience including the speeds actually achieved over the nbn™ network depends on the technology over which services are delivered to your premises and some factors outside our control like your equipment quality, software, broadband plans and how your service provider designs its network.

Watch: Key questions about nbn™ network answered