Internet keeps dropping out on NBN? Try This
NBN drop-outs are one of the most frustrating things to deal with because the cause isn’t always obvious. Your provider runs a remote test and tells you the line is fine. You restart the modem and it works for a day. Then it drops out again. This article covers the most common causes and what to check before calling a technician.
First, Work Out What Kind of Drop-Out You’re Having
Before checking anything, work out what’s actually happening. There are three different problems that people often describe the same way.
Complete internet loss — modem loses sync entirely, all devices lose connection, modem lights change or go red.
WiFi drops out but modem is still connected — internet is working but devices lose the wireless signal. This is a WiFi problem, not an NBN problem.
Speeds drop significantly but connection stays up — connection is live but pages load slowly, Netflix buffers, video calls break up.
Each one has different causes. Knowing which one you have saves a lot of time.
Check the Modem Lights
The lights on your modem tell you a lot. Most modems have an indicator for the DSL or WAN connection, which is the physical link to the NBN, and a separate indicator for WiFi and LAN.
If the WAN or DSL light is red or off during a drop-out, the modem has lost its connection to the NBN network. That points to an external fault or a modem hardware problem.
If the WAN light is solid green but devices still can’t get online, the issue is more likely the modem’s WiFi, a DHCP problem or a device configuration issue.
Common modem light indicators by brand:
TP-Link Archer series — orange WAN light means no internet, green means connected.
Netgear Nighthawk — amber internet light means no connection.
ASUS routers — red WAN indicator means no internet.
Sagemcom F@ST 5366 (common NBN supplied modem) — red broadband light means no sync.
Check the NBN Connection Type
Different NBN connection types have different failure modes.
FTTN (Fibre to the Node) — copper wire runs from the node on the street to your house. The longer and older the copper, the more susceptible to drop-outs, particularly in wet weather. Rain getting into old copper joints is one of the most common causes of FTTN drop-outs in Melbourne.
FTTC (Fibre to the Curb) — fibre runs to a small pit at the kerb outside your property, then a short copper run into the house. Generally more stable than FTTN but the DPU (Distribution Point Unit) in the pit can fail, particularly after flooding.
FTTP (Fibre to the Premises) — fibre all the way to the house. Very stable. Drop-outs on FTTP are usually modem or router related rather than line faults.
HFC (Hybrid Fibre Coaxial) — cable runs from a node to your premises. Susceptible to node congestion during peak hours and signal level issues from the tap on the street.
Fixed Wireless — NBN tower to an antenna on your roof. Weather dependent, line of sight issues and tower congestion can all cause drop-outs.
Knowing your connection type helps narrow down the cause significantly.
Things to Check Yourself
1. Restart the modem properly
Not just power off and on. Power off, wait 60 seconds, power back on. Some modems need the full 60 seconds to clear the connection state properly. A 5 second restart often doesn’t do it.
2. Check for firmware updates
Log into your modem admin panel, usually at 192.168.0.1 or 192.168.1.1, and check whether a firmware update is available. Outdated modem firmware is a surprisingly common cause of instability. TP-Link, Netgear and ASUS all push firmware updates regularly that fix known connection issues.
3. Check the modem temperature
Modems and routers generate heat. A modem sitting in a cupboard or enclosed entertainment unit with no airflow will overheat and drop connections. Move it somewhere with open air around it. If the modem feels very hot to touch, that’s likely contributing.
4. Check all physical connections
DSL or coaxial cable from the wall to the modem seated firmly. Ethernet cable from modem to any switches or devices checked. On FTTN connections, the phone line socket on the wall plate is worth checking. A loose or corroded connector on the wall plate causes more drop-outs than people realise.
5. Try a different ethernet cable
A faulty ethernet cable between the modem and a switch or device can cause intermittent disconnections. Try swapping it out.
6. Check for WiFi interference
If the drop-outs only happen on wireless devices and wired devices stay connected, the problem is WiFi not NBN. Check the 2.4 GHz channel setting in the router admin panel. In suburban Melbourne, channels 1, 6 and 11 are the only non-overlapping channels. Leaving it on auto often results in the router picking a congested channel. Set it manually.
7. Run a wired speed test
Connect a laptop directly to the modem with an ethernet cable and run a speed test at fast.com or speedtest.net. If speeds are fine on a cable but drop on WiFi, the problem is wireless. If speeds are low or intermittent on a wired connection, the problem is the NBN connection itself.
8. Check the drop-out times
Keep a note of when drop-outs happen. If they occur at the same time every day, particularly late afternoon or evening, this points to node congestion or a scheduled task on the modem. If they happen in wet weather, that’s almost certainly a copper line fault on FTTN or FTTC.
When It’s an External NBN Fault
If the modem is losing sync and restarting fixes it temporarily but the drop-outs keep coming back, the fault is likely external. Either the copper line, the node on the street, the HFC tap or the NBN connection point at the premises.
Signs it’s external:
- Drop-outs happen in wet weather
- Modem loses sync completely, not just WiFi
- Restarting fixes it but only briefly
- Multiple devices on wired and wireless both lose connection at the same time
- NBN light on the modem goes red during the drop-out
When this happens, call your ISP and log a fault. Ask them to raise a Telstra or NBN Co field technician to check the line from your premises back to the node or pit. The first level ISP support will try to resolve it remotely. Push for an on-site technician if remote testing doesn’t find anything.
This is where having an independent technician’s report helps. ISPs respond faster when a third party has documented the fault and the remote test results.
Case Study
NBN Drop-Outs Every Evening — Reservoir
A customer from Reservoir called us after three months of NBN drop-outs that his ISP, Aussie Broadband, couldn’t resolve. The connection was on FTTN. Drop-outs happened almost every evening between 6pm and 9pm, sometimes three or four times in a row. Each time the modem would lose sync for two to five minutes then reconnect. His ISP had run remote line tests twice and reported no fault found.
We attended the following morning.
First thing was checking the sync stats in the modem admin panel. His modem was a TP-Link VX220-G2v. Logged in at 192.168.1.1 and pulled up the DSL statistics. Downstream SNR margin was sitting at 4.8 dB. Anything under 6 dB is marginal for FTTN. It means the line has very little headroom and any additional noise will cause a drop-out. Downstream attenuation was 52 dB, indicating a reasonably long copper run from the node.
Checked the event log on the modem. Showed repeated retrains between 5.30pm and 9pm every day for the past two weeks. A retrain is when the modem drops sync and renegotiates the connection with the DSLAM at the node. The timing matched exactly what the customer was describing.
Ran a line test from the modem. Downstream speed was syncing at around 38 Mbps on a 50 Mbps plan, which was lower than expected given the plan tier. Upstream was 18 Mbps, normal for FTTN.
Checked the physical connection at the wall plate. Standard RJ11 connection from the wall to the modem. Found the cable had been bent sharply behind a piece of furniture at a near 90 degree angle for an extended period. Replaced the RJ11 cable with a new one and ran it with a gentle curve. SNR margin lifted to 6.1 dB immediately after the cable swap.
Checked the wall plate itself. One of the two copper terminals had slight oxidation on it. Cleaned the terminals.
Ran a wired speed test. Downstream now syncing at 44 Mbps, closer to the plan maximum for that line length.
Updated the TP-Link VX220-G2v firmware from the TP-Link Australia support page. It had been running firmware from 2021, three major versions behind. The current firmware had specific fixes for FTTN line stability.
Advised the customer to monitor for the next week. If drop-outs continued after the cable replacement and firmware update, the next step would be requesting an NBN Co field technician to check the copper from the premises to the node, as the low SNR margin suggested potential issues further up the line.
He called us eight days later. No drop-outs since the visit.
Total job was one hour onsite. Cost was $120.
The likely cause was a combination of a marginal copper line running close to the minimum SNR threshold and a damaged RJ11 cable introducing additional noise into the line. The peak hour drop-outs were consistent with line noise increasing during the evening when electrical interference from household appliances in the neighbourhood is typically higher.
When to Call a Technician
If you’ve worked through the checks above and drop-outs are still happening, give us a call. We carry proper diagnostic tools, check DSL sync statistics, line attenuation and SNR margins, run wired and wireless speed tests and look at the full picture before making any recommendations.
In our experience, around half of persistent NBN drop-outs are caused by something inside the home, a faulty modem, a bad cable, interference or a configuration issue. The other half are genuine external faults that need to be escalated to NBN Co or Telstra.
Either way we find it. And if it’s an external fault, we can liaise with your ISP on your behalf to get it escalated properly.
Call our internet technicians on 0484 357 559 or email info@computertechnicians.com.au
Available Mon-Fri 9am-5pm. After-hours support available.
