Here's another hint that Apple is building its own video service

We just got more evidence that Apple is building a global network of servers designed to deliver iTunes movies and other Apple content to users as quickly as possible.

For fastest delivery, most big internet companies put content like downloads and software updates onto servers geographically close to its users, using a service called a content delivery network.

For the past 15 years, Apple's CDN of choice has been Akamai.

Now it looks like Apple is ditching Akamai for its own servers and has significantly cut its business with the online infrastructure company.

"Over the last two years, our two largest customers in particular, comprise about 13% of Akamai's overall revenue. As we look ahead to 2016, we expect these two accounts to still be our largest media customers, and they will contribute about 6% of our overall revenue," Akamai CEO Tom Leighton said during its earnings call. The company beat analyst expectations and announced a major restructuring and a $1 billion stock buyback, and its stock surged more than 16% after hours.

Akamai's two largest customers are widely believed to be Apple and Microsoft.

"This seven point change in contribution results from their increased do-it-yourself, or DIY efforts," Leighton said.

It's another sign that Apple's online services strategy has been changing, with the company pushing to bring more and more of its online infrastructure in-house. Apple is expected to open at least three new data centers over the next two years and has increased related spending.

If Apple were to launch a streaming video service, as has been rumored, the CDN that delivers it would be a major factor in terms of the streaming quality and lag that end-users would experience.

Streaming services analyst Dan Rayburn previously reported that sources expected Apple to "have a more active role" in content delivery after opening its data center in Maiden, North Carolina.Rayburn has previously tracked OS X downloads coming directly from Apple, as opposed to through Akamai.

Most recently, Apple CEO Tim Cook put a renewed emphasis on online services during the company's last earnings call.