Wirebook › Glossary › Contention ratio
What is a contention ratio (why is internet slower in the evening)?
In one sentence: How much bigger all the homes' plans added together are than the shared pipe they use, such as 1:20. It works because people rarely use their whole connection at once.
A little more
Past your home, broadband is shared. The houses on a street, or the homes on one split fibre, share a pipe back to the provider, and that shares a bigger one with other streets. Providers build those shared parts smaller than everyone's plans added together, because people almost never use their whole connection at the same moment. The contention ratio is that difference: 1:20 means twenty homes' worth of plans share a pipe the size of one plan.
It works well most of the day. The weak spot is the evening busy hour, roughly 8 to 10 pm, when far more homes stream at once. If the shared part is too small, the pipe fills, it is shared out fairly, and films step down to a softer picture while downloads slow right down. Small things like games and messages barely notice. If your connection is slow at 3 am too, the shared part isn't the problem: look at your own plan or your Wi-Fi.
See it in action
- BonusWhy does the internet slow down in the evening?Picture the internet as water: your house's pipe, one shared pipe under the street and a big main from far away.9 min · interactive
- BonusWhy does the game lag when someone starts a download?Your internet line is a shop with one checkout and a download is a shopper with endless trolleys.9 min · interactive
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