Apple's iOS 9 is expected to cause a boom in the use of IPv6, which could speed up service provider networks but create a lot of work for mobile developers.

The new Apple mobile OS, coming out on Wednesday, will treat the new Internet Protocol as an equal to IPv4 instead of favoring the older system. That will cause iOS devices to use IPv6 much more, as long as apps, websites and carrier networks support it, according Facebook engineer Paul Saab. He led a panel discussion on IPv6 at Facebook's @Scale conference on Monday.

Even when all the pieces are in place for IPv6, iOS 8 only makes an IPv6 connection about half the time or less because of the way it treats the new protocol. With iOS 9, and IPv6 connection will happen 99 percent of the time, Saab predicts.

IPv4 is running out of unused Internet addresses, while IPv6 is expected to have more than enough for all uses long into the future. Adoption has been slow since its completion in 1998 but is starting to accelerate. The release of iOS 9 may give a big boost to that trend.

"Immediately, starting on the 16th, I'm expecting to see a lot more v6 traffic show up," said Samir Vaidya, director of device technology at Verizon Wireless. About 50 percent of Verizon Wireless traffic uses IPv6, and Vaidya thinks it may be 70 percent by this time next year as subscribers flock to the iPhone 6s.

Apple's change should help drive more IPv6 use on Comcast's network, too. About 25 percent of its traffic uses the new protocol now, and that figure could rise above 50 percent by early next year, said John Brzozowski, Comcast Cable's chief IPv6 architect.

IPv6 can simplify networks because it lets enterprises and service providers assign a unique Internet address to every device. Today, they typically recycle a limited supply of IPv4 addresses and use NAT (network address translation) to manage that process.

NAT is extra work for network architects and administrators, and it slows down traffic, Facebook and carriers say.

Limited tests at Facebook earlier this year had shown IPv6 connections were as much as 40 percent faster than IPv4. More rigorous testing showed a boost of about 15 percent, but that's still a significant gain, Saab said. Verizon also says it sees faster responses with the new protocol.

The new protocol will have a bigger impact as new kinds of devices and services start to hit mobile networks. Home automation and the Internet of Things won't be possible without IPv6 because there will be too many devices for IPv4 to address, said Axel Clauberg, Deutsche Telekom's vice president of aggregation and transport IP.

5G mobile networks, expected to serve delay-sensitive applications like autonomous vehicles, won't work with IPv4 either, said Yoon Mingeun, an emerging technology project manager at SK Telecom.

Apple will push IPv6 yet again early next year when it requires all apps submitted to its App Store to support the protocol. That will help to foster IPv6-only operation, eventually cutting down on the need for any IPv4 at all.

That could mean a lot of coding for apps that don't yet support IPv6, said Haroon Khan, an engineer at HealthExpense, a SaaS provider for health insurance claims and billing. Many elements of back-end software would need to be modified to add IPv6 capability, he said.

IPv6 should do some good through benefits like network simplification, Khan said. But it will also change the way developers work. In IT shops that reuse IPv4 addresses internally, programmers get to know certain addresses so well that they just type them into code from memory. With IPv6, everything can have its own unique Internet address. And in any case, the new addresses, at 128 bits, are too large to ever memorize, he said.