Editor’s Corner—Getting inside AT&T, Verizon and CenturyLink’s white box challenges and opportunities

AT&T, CenturyLink, Verizon and social media providers like Facebook are advocating a new way to achieve network virtualization: the white box.

Unlike the traditional proprietary vendor approaches, the white box is poised to break down the silos of provisioning hardware and software, enabling service providers to pick and choose the best elements that fit their unique network needs.

The white box approach can be applied to a range of network functions; take switches for example. A white box switch may come preloaded with minimal software or sold as a bare metal device, which could be assembled by the service provider or a systems integrator partner. In an SDN environment, white box switches are used as an approach to networking where network control is decoupled from the physical infrastructure.

But for all of the excitement created about white boxes, what value and challenges do these systems bring to service providers?

Take a carrier like CenturyLink, which has virtualized fully 60% of its POPs. Bill Walker, director of network and cloud architecture for CenturyLink, said the challenge with an all white box construct is the operator would have integrate all of these functions into its network.

“We’re constantly looking at whether to build, buy, license or acquire in different scenarios for different reasons,” Walker said. “Even with a white box, I doubt we’ll ever go pure white box because that means will have to maintain our own field spares, logistics and that’s probably half the cost.”

CPE, core network challenges, opportunities

Service providers see opportunities to leverage white box network infrastructure in various points of their networks: the customer premise, the core and the edge network. Unsurprisingly, disaggregating these network elements in a white box configuration poses various opportunities and challenges for service providers.

Providing white box-based customer premises equipment (CPE) for business customers—a concept AT&T and Verizon have been implementing—makes sense.

Business customers that purchase AT&T’s FlexWare service will get a fully functional router that can support various services, including SD-WAN and security. FlexWare, which is AT&T’s Universal CPE (uCPE) platform, allows businesses to set up multiple virtual network functions, such as a router and a firewall, on a single FlexWare device.

The service provider’s FlexWare offering continues to resonate with customers. To date, the service is available in over 200 countries on Ethernet and TDM-based technologies supplied by either AT&T or one of its network access partners. 

Likewise, Verizon has also developed its own uCPE concept. In May, Verizon named ADVA Optical Networking’s Ensemble Connector as part of its uCPE solution. Verizon is using Adva’s Ensemble Connector as its network functions virtualization infrastructure on white box servers.

Adva’s Ensemble Connector’s zero-touch provisioning enables Verizon to drop-ship servers directly from the CPE supplier to the end customer, simplifying supply chain logistics. Ensemble Connector further simplifies operational processes with access to a large collection of virtual network functions.

“Verizon’s universal CPE program chose to have a strictly multivendor implementation with different suppliers at every level, which fit in with our approach,” said Prayson Pate, CTO of Ensemble for ADVA Optical Networking. “What it does do is it raises all these places where there’s no specs or the specs are not clear or are invented as they go.”

Pate added that challenge of the white box environment is “where you have to spin these services in an automated fashion is where you start to trip over a few things.”

Despite the initial use of white box-based CPE, AT&T sees initial challenges, particularly in looking at the core network and disaggregating software elements.

John Mendamana, VP of packet optical network at AT&T, told FierceTelecom that disaggregating hardware and software functions becomes more complex in the core part of the network because an outage could take down multiple customers.

“A CPE router is a single deployment with a small blast radius, but if something goes wrong the core of the network it could have a larger impact,” Mendamana said.

That’s not to say AT&T isn’t keen on making a white box part of its network process.

AT&T recently debuted its Open Architecture for a Disaggregated Network Operating System (dNOS) concept. dNOS separates the operation of the router’s “Network Operating System” software from its underlying hardware (router chassis, routing controller and forwarding line-cards). The concept also calls for standard Application Programming Interfaces that provide a framework within the base operating system, data planes and control and management plane.

Disaggregating optical

Service providers are also keen on implementing a white box concept in the optical network. New concepts like OpenROADM, an initiative led by AT&T, Ciena, Fujitsu, Nokia and others, are gaining interest.

As part of its multisource agreement, OpenROADM has developed a set of specifications that define interoperability specifications for ROADMs, including ROADM switches as well as transponders and pluggable optics. Specifications include optical interoperability as well as YANG data models.

In 2018, AT&T plans to deploy OpenROADM elements in its optical network. However, the service provider plans to take baby steps with OpenROADM, focusing its initial builds on 80 km and shorter network spans.

OpenROADM is just one initiative focused on enabling open networking approaches for the optical network.

Facebook has joined a number of service providers such as Telia Carrier and Vodafone to key up the Telecom Infra Project (TIP). This project has created a group looking at Open Optical Packet Transport—a dense wavelength division multiplexing (DWDM) system including open line system and control, transponders and network management. Under this approach, hardware is separated from software and management, and all parts go open source.

The social media company has worked with partners Telia Carrier and Vodafone to test Voyager, a networking solution for Open Packet DWDM networks. Telia Carrier used Voyager to close a link of more than 1000 km at 200G using 16QAM, in northern Europe, for example. Meanwhile, optical vendors like Lumentum, Juniper, Coriant and Infinera have also pledged support for TIP.

Heidi Adams, senior research director for transport networks at IHS, said that it is not as clear how large a benefit TIP will have to the broader service provider community.

“The target market for this seems to be mostly Facebook (who are driving this initiative)—benefits to other network operators are much less clear at this stage,” Adams said. “Key take-aways from our recent survey on this topic is that it is still very early days for optical disaggregation—there are currently more major challenges to work through (e.g. cost/risk/time required for integration, interoperability and operations in multivendor environments) than there are clear, quantifiable benefits.”

As service providers look at virtualizing more of their networks, it is forcing a new dialogue with vendors that had been used to supplying a soup to nuts package of hardware and software with relatively static upgrade cycles. Being a relatively nascent concept, the jury is still out on how impactful white boxes will be, but it’s clear that the service provider community sees value in them as a way to make their networks more agile.--Sean | @FierceTelecom