SDN Technology

AT&T Describes Next Steps for Network Virtualization

John Donovan, head of AT&T's global network, recently described the company's next steps in its ambitious plans to achieve 75% virtualization and software control on its worldwide network, driven by a staggering 100,000% wireless growth between 2007 and 2014.

"While some competitors are still figuring out their SDN strategy, I want to talk about the next two phases of our SDN deployment," the AT&T Inc. (NYSE: T) senior executive vice president, technology and operations, said at a keynote at last month's Open Networking Summit.

The first phase is virtualizing AT&T's network functions, including the mobile packet core, session border controllers, load balancers, routers and firewalls. AT&T is taking these steps first to prove "that our vision and path are the right one," Donovan said.

Mic Drop
AT&T's John Donovan wraps up.
AT&T's John Donovan wraps up.

The second phase is disaggregation, Donovan said. "With this phase, we disentangle all the components in the system," strip them down to core components and rearchitect them for the cloud. "Abstracting is like pixie dust. It lifts everything. You don't even know what you can do until you can get it up."

The first target is AT&T's gigabit GPON OLT equipment in central offices for residential and business customers. These components are part of AT&T's GigaPower service. (See AT&T Testing Virtualized GPON, AT&T Testing Virtualized GPON, and AT&T: Building Gigabit Connections Is Just the First Step.)

Open source commitment
The equipment used for GigaPower is complex and expensive, which puts constraints on deployment, Donovan said. "This is exactly the area where SDN components can really shine." Virtualizing the system increases flexibility, reduces hardware consumption and enables faster scaling to put more functions in a box.

AT&T expects prototypes shortly, with trials and deployments scheduled for next year, Donovan said.

The carrier is creating open specifications for the equipment so that any ODM can build it, Donovan said.

Indeed, all of AT&T's network development is based on APIs, Donovan said. The company has 4,600 APIs, although many aren't for public consumption.

AT&T has a strong commitment to open source. "One tenet of open source is that you don't just take code. You contribute it as well," Donovan said. (See AT&T Makes Case for Open Source Sharing.)

Use secret sauce sparingly
While at the ONS conference, AT&T participated in a proof-of-concept for Central Office Re-architected as Data Center (CORD), along with chip vendors PMC-Sierra Inc. and Sckipio Technologies and the ONOS project, which is led byON.Lab. The PoC encompasses central office equipment (GPON and G.fast) and customer premises equipment (CPE). (See AT&T to Show Off Next-Gen Central Office.)

AT&T has developed a software tool to configure equipment using YANG, and has released the tool into open source through the OpenDaylight Project, Donovan says.

The company also contributed to the OPNFV Arno build, an open source NFV platform. (See OPNFV Formally Issues First Release, Arno.)

Making the transition to open source requires strategic thinking, Donovan said. Some code should remain proprietary -- but not a lot. "You have to define internally what is going to be open source and what will be your secret sauce," he said. "That sauce should be Tabasco size, not in gallon jars." (Editor's Note: I buy Tapatio Hot Sauce by the quart. But I get that Donovan is talking about normal people here.)

Technology that's heavily resource-intensive, takes a long time to develop and doesn't produce a lot of code is a candidate for development as a proprietary solution in a standards-based process. Other areas are better for open source. "This is an art, not a science. Everyone has a secret sauce," Donovan said.

Currently, 5% of AT&T's code is open source, with a target "north of 50%," Donovan said.

Open source is a different business model from how AT&T is used to working, and "fundamentally changes the relationship we have with suppliers," Donovan said. AT&T collaborates with suppliers and other outside organizations now far more than it has previously.

AT&T has already introduced SDN-based products, including Network On Demand, which went from idea to trials in six months, Donovan said. Network On Demand allows customers to increase or decrease network bandwidth as needed in real time. "That means they can use just what they need when they need it," Donovan said. Trialed initially in Austin, Network On Demand is available today in more than 100 markets "and it's getting rave reviews." (See SDN Powers AT&T's Rapid On-Demand Expansion.)

Next page: 'Audacious' changes

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