What the iOS 5 update did to ISP traffic

The uptake of iOS 5 among Apple customers last week was fast and far-reaching, which is of course good news for Apple. But what did that look like to the ISPs who provide the bandwidth for Apple customers to update? One of them, Sonic.net, an independent ISP in the San Francisco Bay Area, just released this chart, which sheds light on the huge bump in traffic an iOS update can bring.

Here’s what the company said about the chart on its blog:

The answer is that yes, there is a substantial increase in traffic the day after the update was released. We host the Apple update content locally on AkamaiCDN servers in our datacenter, so this doesn’t affect our network edge, but you can see the bump in traffic from the CDN cluster itself here.

Last Wednesday Apple (s aapl) released the latest version of its mobile operating system, iOS 5. Apple confirmed that 25 million users had already upgraded to iOS 5 by Monday. Localytics then reported Monday that one in three devices that could be upgraded to iOS 5 were, within five days of the OS’s release.