Microsoft just scored a marquee deal for its cloud business, announcing Wednesday that AT&T will use the company's Azure infrastructure and move most of its employees to the Microsoft 365 package of productivity apps and security services.

The multiyear deal is worth more than $2 billion, according to a person familiar with the matter who asked not to be named because the terms are confidential. For Microsoft, which is chasing Amazon Web Services in the cloud infrastructure market, AT&T represents both a hefty buyer and a highly recognizable brand with significant data storage and computing needs for its more than 250,000 staffers.

Beyond AT&T's own internal use of Microsoft technology, the companies are working together on developing tools for artificial intelligence and high-speed 5G wireless, and plan to announce additional services later this year.

"With things like 5G coming together, we absolutely think the combination of AT&T and Microsoft can really go fulfill the demand which is going to be very broad-based across what is commercially led innovation," Microsoft CEO Satya Nadella told CNBC in an interview. "This next phase of, I'll call it the cloud and edge and AI era, will be led by what I would broadly call more production versus just consumption."

Accenture estimated last year that U.S. telecom operators will spend $275 billion over seven years to build out communications networks for autonomous cars and the world of connected devices, or internet of things.