When iOS 7 launched, downloads for the new firmware made up about 20 percent of one ISPs total downloads.
Some recently-released statistics show that one ISP (unnamed) saw 20 percent of its total usage go into folks downloading iOS.
According to the report, the iOS 7 downloads consistently made up over 15 percent traffic throughout the rest of the day.
Heres a portion of the report:
“Most interesting is the fact that the launch noticeably increased the total volume of traffic during peak hours. This presents a unique challenge for operators, since they must engineer their networks for peak demand, and Apple product launches and software updates are infrequent in nature,” Sandvine wrote. “Several of Sandvine’s customers were closely monitoring the traffic demand the launch would cause, and based on the results we observed, we expect they will have a plan in place to manage the load when iOS 8 launches next year.”
You can read it more in detail at Ars Technica.