EOFY sale! High-speed Fixed Wireless available from $69 per month! Opticomm and nbn® discounts also available.

20th March 2020


How contention ratios can affect your nbn™ speeds

Written by Team Pentanet

20th March 2020



Looking to get superfast nbn™ internet connections in Perth? Awesome, you’re in the right place with Pentanet!

While we know that Pentanet is the top contender in the market, it’s normal to research and compare the plans you see from different providers. With everyone offering speeds that - on paper - look the same, you’re probably wondering what the difference is between them all – fair enough! Read on to learn about one major consideration: choosing the right internet provider for you.

It’s not just about the advertised speeds.

Sure, many plans seem to have the same speeds and data allowance, but one major factor gives some internet service providers the edge over others… it’s a little thing called ‘contention,’ and it makes a BIG impact on how your internet service is delivered to your home or business.

Contention is the term used to describe how many people are attempting to use a provider’s total available capacity. It is usually shown as a ratio of users to data sold. It’s common to find a contention ratio of ‘50:1’, which means there are 50 people that might attempt to use 1 megabit per second of capacity at any given time.

The Internet Freeway

Now, if you prefer a good analogy, think of road traffic on the freeway. You can cruise along consistently, hitting that top speed limit when you're the only car on the road. But consider peak-hour on the roads – when it’s bumper-to-bumper (or ‘buffer-to-buffer', as we say!), it’s nearly impossible for everyone to reach 100km/h if there aren't enough lanes to support the traffic.

The same thing can happen with your internet service. Like the freeway, the nbn™ has a peak-hour too, typically between 7pm-11pm when everyone has finished dinner and gets their devices out to stream, browse and play. When many people are all trying to share the same amount of data, it can cause congestion and slower performance - even if your plan speeds are high.

nbn™ plans are required to display the Typical Evening Speed, the speed you can expect your line to receive during this peak-time. It’s common to find an ‘nbn™ 100’ plan with a Typical Evening Speed of between 80-90Mbps during this time.

CVC 101 – What is CVC, and why does it matter?

Now you may be thinking that there aren’t any roads on the internet (correct!), but there is another piece to the contention puzzle called the Connectivity Virtual Circuit or ‘CVC’. The CVC sets how much traffic can pass through your service provider’s network to the outside world at any given time.

Much like roads, not all CVCs are equal. Some can be wide and allow many users to travel fast and direct to their destination, all at the same time. Other CVCs may be smaller, so internet users (like cars!) experience heavy traffic and the whole thing slows to a crawl.

The size of the CVC (and the number of users) sets the limit to how much data gets shared between you and other internet users. If you’re sharing a road with 20 people, you’re more likely to be able to travel at a consistent speed than when you’re sharing with 500 people. Even an eight-lane highway can get jammed-up when thousands of cars are trying to use it simultaneously.

Unlike a highway, though, CVC isn’t a physical thing - and like the name implies, it’s a virtual construct of nbn™, which is designed to aggregate all the traffic a Retail Service Provider (like us!) transfers in and out of the nbn™. Like it or not, it’s a fact of life for all nbn™ RSPs!

What does it mean for me at home or work?

Most consumers are just concerned with their plan's speed, but you should also be looking at the contention ratio we discussed before.

While most ISPs won’t disclose their contention ratios (often because it is dynamic and frequently changing), it is worth looking at the Typical Evening Speed advertised on a provider's plan. A higher typical evening speed could mean a lower contention ratio, so you’re less likely to ‘suffer the buffer’ during peak times. A provider with lower contention can provide more consistent performance and buffer-free happiness during peak-time on the internet highway. At Pentanet, we pride ourselves on maintaining a low-contention network to give you - the consumer - the best possible experience at all times of the day.

Alternatively, you could bypass the freeway altogether and get yourself a chopper!

While most of Perth is struggling on the ‘internet freeway’ during peak times, Pentanet’s Fixed Wireless internet flies direct to your home or business to deliver consistent, reliable speeds of 120Mbps. Our Fixed Wireless network exists outside the nbn™ and so isn’t subject to any CVC limitations - there’s no congestion in the sky!


When looking for the best internet for you, it is good to remember that advertised speeds aren’t the only factor at play. For the best experience with your internet at home or work, choose a provider with fast speeds, a low contention ratio, reliable service and local support.

Luckily for you, you’ve already found one :) When you’re ready to love life #PoweredbyPentanet, let’s chat.