CenturyLink has big plans for central office virtualization, and the first place the company is implementing those plans involves DSL service delivery, as news announced today illustrates. The company said it was the first carrier to use its own virtualized broadband network gateway (vBNG) based on central office re-architected as a datacenter (CORD) concepts.

As Adam Dunstan, CenturyLink vice president of SDN/NFV engineering, explained in an interview, the company targeted the broadband network gateway for virtualization because “it’s one of the most complex routers you can buy.” BNGs combine authorization control, routing and other functions on a single piece of equipment and as Dunstan explained, that makes it “very complicated to do Layer 2 services and move workloads around.”

The vBNG that CenturyLink has implemented runs on “white box servers” and separates access and routing functions, Dunstan said. He noted that the work CenturyLink has done in this area is expected to also support GPON in the future.

“The access and physical layers will be different but the bill of materials will be much more common,” Dunstan observed.

CenturyLink’s vBNG deployment doesn’t strictly adhere to CORD specifications developed as part of the Open Network Operating System (ONOS) project, noted Bill Walker, CenturyLink director of network and cloud architecture. “We have our own operations support systems and business support systems and our own orchestration and automation tools; one size doesn’t fit all,” observed Walker. But the concepts employed are similar.

Central Office Virtualization
Dunstan noted that CenturyLink started working on central office virtualization “a long time ago” – so long ago that the industry wasn’t using the term “CORD” at that time.

The company’s work “has let us heavily decompose some very complex pieces of equipment,” Dunstan said. Moving forward the company expects to virtualize 100% of its network with the goal of saving costs and enabling faster response to customers, including giving customers the ability to activate their own services.

CenturyLink has about 3,500 central offices and will target them for virtualization based on where the company expects the best return on the investment, Walker said. Plans could include consolidating central offices, noted Walker. Functionality of some smaller central offices might be moved closer to the core, while the existing real estate continues to serve as a wiring center, he explained.

Dunstan and Walker declined to provide a detailed answer about where CenturyLink will go next with regard to central office virtualization. But according to Dunstan, “The first thing we’re really focused on getting done is getting the underlying infrastructure working [in a] robust, reliable [manner]. You will see a lot of focus on key foundation technology this year that will let us rapidly bring out lots of optimizations.

“There are tons of opportunities; sifting through them is a tough one.”