Why is my NBN so slow?


We often get asked ‘Why is my NBN so slow?’ We have the answer for you right here.

If you’ve only just switched to the NBN and you’re noticing that your internet speeds are slow, don’t worry.  Slow broadband is an issue with multiple reasons behind it, so knowing why this is happening may help resolve the problem faster.

1. Bandwidth Throttling

Bandwidth throttling might be one of these causes if you’ve experienced this before. Bandwidth throttling occurs when a certain site (commonly known for hosting pirated content) becomes too popular among other users on that network or region’s connection speed. Internet Service Providers will then use bandwidth throttling as their last line of defence since they do not want to experience an overload in traffic, which could lead to service interruption for all customers (a no ISP wants).   This process is also done to protect other customers on the network because when sites are widely used for illegal purposes by other users, many other legitimate sites get affected too.

*If you’re experiencing bandwidth throttling but do not know why it’s best to contact your ISP directly for more information about this process or what legal actions have happened that would lead them to facilitate this. *

2. Installation issues

Another cause could be how your NBN connection was installed in the first place. Installing an NBN connection isn’t as easy as cutting a cable cord and watching TV via Wi-Fi instead of cable. There are certain necessary materials you need beforehand before installation can commence (like being able to supply power) or if either party decides they want to perform self-install, certain hardware is needed as well. You may not have these things if you’re a renter and the previous owner took these with them or already had an NBN connection installed before you moved in.

*If that’s the case, it might be best to pay for professional installation or contact your ISP directly to see if they’ll install a new NBN™ connection to your premise for free (as long as you meet their criteria).*

In some situations, this may not be a problem. If you have a router at home and live in a non-metro area between the green and yellow plans of your ISP’s NBN™ speed tier i.e. 25/5 Mbps or better, having slow speeds shouldn’t be an issue for everyday browsing and streaming since most websites have less than 5mbps data usage per page load. So basically, if less than 5% of an average website uses over 1mbps (1000kbps) whilst it’s loading – unless your plan is under 25/5Mbps – you should still be able to browse almost every webpage without much trouble if you’re experiencing slow speeds on NBN™ alone. Your internet connection is just that: broadband; and, therefore, your NBN™ connection shouldn’t be the only factor that determines the speed of your internet connection.

3. Network congestion

If you don’t use a router or have more than 1 device connected at once (i.e. not just a PC using Wi-Fi), you probably still experience slow speeds on the NBN™ even if you’re within 25/5Mbps because of congestion or an unoptimized network . You’ll notice that although you’re receiving good enough speeds via Wi-Fi but switch over to 4G and it’s very sluggish – this is due to external factors such as congestion.

4. Distance from the node

If you’re on a Fibre to the Node (FTTN) network, the connection speed you receive is largely dependent on how far away your node is. The further a signal has to travel in old copper wires, the worse it gets, and being at the end of the line can result in a slower connection than someone who’s right next to it. Even a few hundred meters might make a significant difference.


If you live in an NBN-ready house, but your home is not connected to the network yet, this may result in a connection that is slower than anticipated. This happens for a variety of reasons, including faulty installations or simple bad luck on your physical location. There’s no way to improve the quality or functionality of your connection since it’s determined by the NBN rollout.


Moving into a slower tier option: This isn’t a complete answer, but it does offer a way to avoid wasting money. If a company’s technical limitations prevent them from delivering on the speed they promised when you purchased your plan, they are obligated by law to allow you move to a less expensive speed option. Call your provider’s customer care department and talk about your alternatives.

Using mobile broadband. If you’re dissatisfied with your connection, consider investing in mobile broadband or home wireless broadband, both of which utilize the same network as a mobile phone. If you have good network coverage with your mobile provider, it’s likely that you’ll have a decent mobile broadband or home wireless connection.

While there are several ways to get unlimited mobile data at home, you’ll commonly have to deal with lower data caps for the same price as regular mobile broadband, which is better than nothing.

5. Virus/malware infection

If you’ve tried all of this and are still experiencing slow speeds, there are possibilities of a virus or malware infection as per our experience.

Yes, virus or malware infections does slow down your network. This occurs due to the fact that the virus or malware changes and disrupts your computer and internet connection settings. They can operate in the background and use the internet, which leads to an increase in bandwidth usage. Slower web surfing is the result. Recently, we’ve encountered several computers infected with Bitcoin Miners. You may not notice anything amiss on your computer, but if you do check the Task Manager (Ctrl+Shift+Esc), you will see a process called ‘javaw. exe’ or a similar process running more than usual.

Once they’ve gotten a foothold in your system, adware bitcoin miners stay on your machine as installed programs or lines of code buried in RAM, making them far more hazardous than other types of crypto jacking.

We suggest you run an Antivirus scan on your system to ensure that the infection is removed, and it should be back up to full speed shortly afterwards.

If you are unsure how to remove such malware from our computer, our friendly computer repair specialists are more than happy to look into the issue for you.

If you are still having issues with your NBN then you may need to get in touch with a technician to troubleshoot your network.

I am a computer engineer holding a bachelor's degree in Computer Science, complemented by a Master's in Business Administration from University of Strathclyde, Scotland. I currently work as a Senior IT Consultant in Melbourne, Australia. With over 15 years of...