Sprint Corp. (NYSE: S) and Ciena Corp. (NYSE: CIEN) announced today that they completed a lab trial last month of 400G running alongside live network traffic. However, you shouldn't expect the 400G bullet train to arrive at your doorstep anytime soon. Sprint said it has no specific timing for 400G commercial deployment.

The 400G deployment "will be dictated by when our data and video customers for wireless and wireline need it," Mike McRoberts, director of product management and development at Sprint, told us. "The beauty of the trial is that we proved to ourselves 100G isn't the end game, and we can keep increasing."

For Sprint and many other carriers, 100G is just reaching the starting line. Sprint and its vendor partner announced the 400G trial in tandem with Sprint's completed deployment of its first 100G long-haul circuit between Chicago and Fort Worth, Texas. Both the 400G test (which took place in Silicon Valley) and the 100G deployment fulfill a timeline commitment the companies outlined about 14 months ago, when they announced Sprint would deploy Ciena's 6500 packet-optical platform. (See Sprint Picks Ciena for 400G.)

Sprint has yet to announce a service offering in connection with its initial 100G deployment, but McRoberts hinted that at an announcement on the carrier's Ethernet Wave service family would be forthcoming. The circuit has been proven to support live transmission up to 2,100km without signal regeneration.

"We have customers who have given us requirements for 100G for things like connecting between datacenters," he said. "The customer impact of that transmission distance without regeneration is that we can improve our SLAs and be sure we can deliver on what we promise."

So far, Sprint has not said which network routes will be in line next for a 100G upgrade. With that in mind, it may seem early to be talking about 400G, but several carriers and vendors have been doing exactly that for months. There have been several 400G advancements, but standards remain a work in progress. The IEEE 400G standard, for example, is not likely to be finalized until around 2017. (See: T-Systems & AlcaLu Try 400G and Why the IEEE Picked 400G Over Terabit.)

Nevertheless, "we'll need 400G" in the foreseeable future, "because data demands are growing geometrically," McRoberts said.

— Dan O'Shea, Managing Editor, Light Reading