Knowledge HubTM
What is contention ratio?
- Date Posted: 18.10.2021
- Video Length: 2 mins 25 secs
- Written by: Exa Networks
Many things can affect the speed of your broadband connection but one that has a big impact is contention ratio. We know you must be thinking, what is it and more importantly how does it affect you? Let us explain.
What is it?
Contention ratio is how many other people are sharing the same internet connection, and therefore bandwidth, as you at any one time. The higher the contention the more likely you are to slow down at peak time.
If you think about roads, we know it sounds random, but just bear with us for a second. If everyone is trying to use the same road at the same time then you end up with a traffic jam. A five minute journey can easily take 40 minutes or more, which can be really frustrating.
The same applies to bandwidth, if everyone is using it at the same time the connection can become congested and you may see your speeds drop, particularly at home in the evening.
If your contention ratio is 50:1 that means upto 50 people are all using the same connection as you at any one time. If the bandwidth of the shared line is around 100Mbps, you could receive around 35Mbps on average. However, if all 50 people are using it at the same time, then the bandwidth you receive could be as low as 2Mbps.
Which services does it affect?
Contention ratio doesn’t impact every connection although it does affect quite a few. ADSL, FTTC, Gfast, FTTP and GPON are all contended services which means if you have one of these connections other people will share the same bandwidth as you.
The good news is, corporate connections tend to offer better contention ratios than domestic broadband packages, so the impact isn’t that profound in a business or educational setting.
Even better, when it comes to leased line and dark fibre connections, contention isn’t an issue because it is effectively a private service, you will receive 100% of the bandwidth at all times.
How do I find out my contention ratio?
Internet service providers don’t tend to publish contention ratio data, so it can be really difficult to know what your contention ratio is.
However, what they do provide is your minimum download and upload speeds which do take into account an estimate of your contention ratio.
How can contention ratio be managed?
The way in which contention and congestion are managed has changed. It used to be that contention was at the local exchange, so it would be the amount of users all competing for bandwidth from the local internet exchange. Now, the contention happens at a national level so the congestion is spread out more evenly and it’s only really a problem at peak times.
Individual ISPs also have web traffic management systems to deal with contention. These systems limit congestion on their network, ensuring the stability of your line during busy periods and maintaining high speed performance.
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