Cables and sockets

Which cable is which?

Four kinds of cable turn up in Australian homes. They look alike at a glance and do very different jobs. Mix them up and you end up with a plan that cannot work, such as expecting a phone socket to become a network point.

Tell them apart by the plug

Not drawn to scale. When in doubt, count the gold contacts.

Optical fibre
Small green square
Coax
Screw-on, one pin
Ethernet
Wide, eight contacts
Phone
Narrow, four contacts
Old phone
Big cream block

What each cable can carry

Cable	The NBN into your home	A home network	TV aerial or pay TV	A landline phone
Optical fibre	Yes, on FTTP	No	No	No
Coaxial cable	Yes, on HFC	With adapters	Yes	No
Ethernet cable	No	Yes	No	No
Telephone cable	Yes, on FTTN, FTTB and FTTC	No	No	Yes

The one to remember: telephone cable cannot carry a home network. The phone sockets around an older house are not spare data points.

Optical fibre

The NBN’s own cable on Fibre to the Premises

A hair-thin strand of glass that carries data as pulses of light.

How to recognise it

A thin, light lead, slimmer than a phone charger cable, usually white or yellow.
A small square plug on the end, often bright green.
It goes into the NBN connection box and nowhere else in the house.

Where you will find it

From the street to a grey NBN utility box on an outside wall.
From there to the NBN connection box indoors, usually in the garage, a hallway or near the front of the house.
Not in the walls between your rooms. Home networks use Ethernet.

What it can do

Carry the fastest plans there are, over any distance, with no interference.
Link two separate buildings safely, because glass does not conduct electricity.

What it cannot do

Plug straight into a computer, TV or router. Those need Ethernet.
Survive rough handling. Do not bend it sharply, stretch it or unplug it.
Be moved or extended by anyone except a technician.

Coaxial cable

Coax. TV aerial cable, pay-TV cable, and the NBN’s cable on HFC

A thick round cable with one copper wire down the centre, wrapped in insulation and a metal shield.

How to recognise it

A thick, fairly stiff round cable, black or white, about as thick as a pencil.
A metal screw-on connector with a single thin pin in the middle.
Wall plates with a round, threaded socket.

Where you will find it

Behind the TV, running to the antenna on the roof.
At wall plates left over from pay TV.
On HFC connections, from a wall plate to the black NBN connection box.

What it can do

Carry TV signals.
Carry the NBN on HFC connections, including the very fastest plans.
Carry a home network between two rooms, using MoCA adapters fitted by a registered cabler.

What it cannot do

Plug into a computer or router. The connector is completely different.
Be split freely. Every splitter weakens the signal, and on HFC that causes dropouts.

Ethernet cable

Network cable, data cable, LAN cable, patch lead. Sold as Cat 5e, Cat 6 or Cat 6A

Eight thin copper wires twisted together in four pairs. The standard cable for home and office networks.

How to recognise it

A round or flat cable, commonly blue, grey, white or yellow.
A clear plastic plug about as wide as your little finger, with eight gold contacts and a springy clip.
Printing along the cable that says CAT5E, CAT6 or CAT6A.
Wall plates with a socket a little wider than a phone socket, sometimes labelled Data.

Where you will find it

Between the NBN connection box and the router.
From the router to computers, TVs and games consoles.
In newer homes, inside the walls: from data points in the rooms back to one cupboard or the garage.

What it can do

Carry 1,000 Mbps on Cat 5e, and more on Cat 6 and Cat 6A, for up to 100 metres.
Power access points and cameras down the same cable (Power over Ethernet).
Give any device the full speed of your plan with no interference.

What it cannot do

Bring the NBN in from the street. That arrives by fibre, coax, phone line or radio.
Run between separate buildings without special precautions. Fibre is the right cable for that.
Be installed inside walls, floors or ceilings by anyone but a registered cabler.

Telephone cable

The old copper phone line. Still the last stretch of the NBN on FTTN, FTTB and FTTC

Two or four thin copper wires, designed a century ago to carry voices.

How to recognise it

A thin, often flat cable in cream, grey or black.
A small clear plug with two or four gold contacts, clearly narrower than an Ethernet plug.
In older homes, a large cream plug with three flat prongs.
Wall plates in the kitchen, the hallway or a bedroom.

Where you will find it

From the street into the house, ending at the first phone socket.
Hopping on from that socket to others around the house.
On FTTN, FTTB and FTTC, between a wall socket and the modem or NBN box.

What it can do

Carry the NBN on copper-based connections: up to about 100 Mbps on a short line in good condition.
Carry an old landline phone service.

What it cannot do

Carry Ethernet. It has two or four wires where Ethernet needs eight, and they are not twisted tightly enough to keep the signal clean.
Become a network point by changing the plug. A phone socket in another room is not a spare data point.
Safely take the wrong plug. A phone plug slides into an Ethernet socket and can bend the outer pins. An Ethernet plug will not fit a phone socket at all.

The one exception: Some homes built or renovated since the early 2000s had their phone points wired with Cat 5e cable. If the printing on the cable in the wall says CAT5E, and each point runs back to one place instead of hopping from room to room, a registered cabler can convert those points to Ethernet.

Before you run a cable: the law

Cable hidden in a wall, floor or ceiling must be installed by a registered cabler, even in your own home. Ready-made leads run in the open are fine to do yourself.

You can do this yourself

Plug in ready-made (factory-fitted) leads between your equipment.
Run a ready-made lead in the open: along a skirting board, around a door frame or under a rug edge, as long as no part of it is inside a wall, floor or ceiling.
Plug in routers, mesh points, switches, powerline adapters and PoE injectors.

Needs a registered cabler

Any cable that passes through a wall cavity, a ceiling or roof space, or under a floor.
Fitting wall sockets, or putting plugs on bulk cable to make your own leads.
Re-using TV coax in the walls for data (MoCA adapters).
Cable or conduit between separate buildings, and moving NBN equipment.

The work must be done, or directly supervised, by a registered cabler. There is no exemption for owner-occupiers.
The maximum penalty for unregistered cabling work is 120 penalty units, about $43,000 in 2026.
When the job is finished, the cabler must give you a signed statement that it complies with the wiring rules. Keep it.
Typical cost in 2026: about $150 to $400 for one straightforward Cat6 point, less for each extra point on the same visit.

Find a registered cabler ACMA: checking a cabler

...and why it is not a job to try yourself

Safety warning: Cabling inside walls, ceilings and floors must be done by a registered cabler. It is dangerous work that can seriously injure or kill: electrocution from hidden live wiring, asbestos in older homes, and falls.

Electrocution: Walls, ceilings and floors hide live mains wiring. Drilling or cutting into it, or touching old or damaged wiring in a roof space, can kill. Switching the power off at the switchboard does not make everything safe: the supply line from the street and solar panel cables stay live.
Asbestos: A home built before 1990 is likely to contain asbestos, and one renovated before 2004 may: in wall and ceiling sheeting, eaves, kitchens, bathrooms and laundries, floor coverings and old meter boards. Drilling, cutting or sanding it releases fibres that can cause fatal lung disease many years later. You cannot tell by looking. Only a laboratory test can.
Falls: Falls from ladders and roofs are a leading cause of serious injury in work around the home. In a roof space only the timber frame holds your weight: a step between the beams goes straight through the ceiling.
Heat and tight spaces: A roof space can be dangerously hot, especially in summer. Roof and underfloor spaces are cramped and dark, and hard to get out of quickly if something goes wrong.
Hidden pipes: Water and gas pipes run inside walls and under floors, exactly where a drill bit or saw goes.
Faulty work: A data cable run too close to power wiring, or through the wrong part of a building, can become live, start a fire or let water in. That is why the work is regulated, and unregistered work may affect your insurance.

Anything on this site about how cabling is done is there so you know what the job involves, what to ask for and what good work looks like. It is general information, not training and not professional advice. If you are not a registered cabler, do not do the work yourself.

Find a registered cabler Asbestos: advice for householders Roof spaces and electricity