Fault finding & troubleshooting
Why is my internet connection unstable?
An unstable internet connection comes from one of three places: the WiFi, the wiring and equipment in your home, or the network outside. One test tells you which. Plug a laptop into the modem with a cable. If it is steady there, the problem is WiFi. If it is not, it is the line.
Start here: which kind of unstable is it?
An unstable connection feels the same whatever the cause: pages hang, calls freeze, the TV buffers. The cause is in one of three places, and one test separates them.
Plug a laptop straight into the modem or router with a network cable, turn the laptop’s WiFi off, and use it for an hour.
| What happens on the cable | Where the problem is | Go to |
|---|---|---|
| Steady, while WiFi devices still play up | The WiFi | WiFi connectivity problems |
| Drops out or stalls on the cable too | The line, the wiring or the modem | Cabling and sockets, then NBN network issues |
| Fine by day, poor every evening | Congestion in the network | NBN network issues |
| Drops when it rains or on hot days | A copper joint, the lead-in or an outside fitting | Outside interference and the weather |
One day, four ways to drop out
An illustration of the four patterns, not measured data.
The wiring, a socket or the equipment. Scattered through the day, and on the cable as much as on WiFi.
Read: Cabling and sockets, then Equipment problems
Congestion in the network. Fine all day, then bunched into the evening, when the house and the street are online.
Read: NBN network issues
Water in a copper joint, the lead-in or an outside fitting. Under the rain and just after it, on the cable too, and clear on a dry day.
WiFi coverage, not the line. The laptop on the cable stays connected all day while the phones and the TV keep losing it.
If it drops on the cable too and you would rather have it found than chase it, an internet technician can test the line and your wiring on site.
Check your speed first Run it on the cable first, then on WiFi in the room that gives you trouble. Two numbers, and you know which half of this page to read.Substandard cabling and sockets
On fibre to the node, fibre to the curb and fibre to the building, the internet runs over the old phone wiring in your home. That wiring was put in for telephones, in one of two layouts:
- Star. A cable from each socket back to one point.
- Daisy chain. A cable from the first socket to the second, the second to the third, and so on.
Both leave extra sockets hanging off your internet line. Each one is a bridge tap, and the signal echoing off those dead ends is a leading cause of an unstable copper connection. More in what a bridge tap is.
The sockets themselves matter too. An old three-pin socket with an adaptor, a corroded connection or a worn lead will each drop a service.
What fixes it
- Take the unused sockets off the line, so there is one direct path from the street to the socket you use. That is a new NBN wall socket on its own cable, with the old ones disconnected.
- Replace the socket in use if it is an old type, so no adaptor is needed.
- Run a new cable from where the line arrives to the socket, if the old cable tests poorly.
These are jobs for a registered cabler. If you also want a phone working on the old sockets, that is a separate job: getting the phone sockets working again. There is a worked list of the home-wiring causes, each with a job on video, in is your NBN dropping out.
This job shows how far wrong a line can be wired. A fibre to the curb service had not worked for about a month.
Watch: Fixing a Month-Long NBN FTTC Issue: The Shocking Discovery at the Customer's Home
WiFi connectivity problems
WiFi is the most common reason a good connection feels unstable. It is radio. Distance, walls and other networks all weaken it, and one router in a corner will not cover a long or two-storey home.
Two tests
- Beside the router. Run a speed test on WiFi next to it. If you get close to your plan, the connection coming in is fine.
- Around the house. Run it again in each room. Where the number falls away, you have found the edge of your coverage.
What fixes it
- Move the router into the open, up high, as near the middle of the home as it will go.
- A mesh system. Several units that work as one network. See how to boost a mesh WiFi signal.
- Cabled WiFi points. A data cable to one or two WiFi points gives the steadiest result of all.
- Not usually an extender. See do WiFi range extenders really work.
When the house needs more than a moved router, a WiFi technician works out where the signal has to reach and puts it there.
In this job, a factory and office had a sound internet line and no usable WiFi upstairs.
Watch: Mesh Wi-Fi Killed The 4G Dongle Dependency | 0 to 102 Mbps
NBN network issues
Sometimes the instability is in the network, and how likely that is depends on which NBN you have.
- Fibre to the node (FTTN). The longest run of old copper. Speed falls with distance from the node, and old joints in the pits let water in. See what fibre to the node is.
- Fibre to the curb (FTTC). Fibre to the pit, then your copper lead-in. The lead-in and its joints are the weak points. See what fibre to the curb is.
- HFC. Shared with the street, so it can slow in the evening, and its cable fittings corrode. See what HFC is.
- Fibre to the premises (FTTP). Rarely the line. Look at the router and the WiFi.
When we open pits on the copper types, we often find old joints that have been wet for years, and repairs wrapped in plastic and tape. A line like that works on a dry day and fails on a wet one.
What to do
Report it to your provider, with dates and times, and ask for a fault to be lodged with NBN. A provider acts faster on a pattern than on “it keeps dropping out”. If you are told the fault is in your home’s wiring and you doubt it, that can be tested at the boundary, which is what an independent NBN technician does. There is more on finding an NBN fault and proving which side it is on.
NBN alternatives
If the line cannot be made steady and an upgrade is not available, there are other ways to get online.
- 4G and 5G home internet. A router with a SIM card, using the mobile network. Quick to set up and independent of the phone line. Speed depends on signal and on how busy the tower is. See how to choose a 4G router.
- The fibre upgrade. Many fibre to the node and fibre to the curb addresses can now move to fibre to the premises, which removes the copper altogether. See the fibre upgrade explained.
- Satellite. For properties out of reach of both.
Outside interference and the weather
- Water. Rain filling a pit, or getting into a joint or an outside socket, shows up as dropouts during and after wet weather.
- Heat. A joint that opens up as it warms gives dropouts on hot afternoons.
- Roadworks and digging. A lead-in that has been knocked or cut. Where the cable from the street needs building again on your property, lead-in cable installation does that last stretch, ready for NBN to connect.
- Household devices. Microwaves, baby monitors and cordless phones share the 2.4 GHz band with WiFi. Using the 5 GHz band, and moving the router away from them, clears it.
There is more in does weather affect your internet.
Equipment problems
- An old or overheating modem or router. Keep it in the open, not in a cupboard.
- Damaged leads. Bent pins, a crushed cable, a lead the dog has chewed. Leads are cheap. Swap them before anything else.
- Out-of-date firmware. Turn on automatic updates.
- The power board. A modem on a crowded, cheap power board can reset when another device switches on. Give the NBN box and the modem a wall socket of their own.
When to get help
If the cable test is unstable, the simple checks have not helped and your provider’s tests say the line is fine, the next step is to have the line and the wiring tested on site. That finds out which side the fault is on, and it settles the argument either way.
If the connection holds and is simply slow, see why your NBN is slow.
Frequently asked questions
How do I fix an unstable internet connection?
Find out where it is unstable first. Plug a laptop into the modem with a cable and use it for a while. Steady on the cable means the fault is WiFi: move the router, or add a mesh system or a cabled WiFi point. Unstable on the cable means the line or the modem: check leads and sockets, then report it to your provider.
Why is my internet unstable at night?
Usually congestion. More people are online in the evening, in your house and in your street, and the connection is shared at several points. If a cable test is fine in the morning and slow at night, the cause is in the network or your provider's capacity, not in your home.
Why is my internet unstable when it rains?
Water is getting into a copper joint, the lead-in cable or an outside socket. This affects fibre to the node and fibre to the curb, and on HFC the fittings on the cable. A fault that follows the weather is a line fault, and it is worth logging the dates to show your provider.
Can a modem cause an unstable connection?
Yes. A modem that overheats in a cupboard, one that is many years old, or one on a failing power supply or a crowded power board will drop out. Before replacing it, move it into the open, give it its own power point, and see whether a laptop on a cable still drops.
Need this fixed rather than explained?
This is written from the field. When the fault needs a technician on site, this is where to go next.