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Software-defined WAN: The old way of building branch networks is dead

In the software-defined WAN, we'll provision virtual overlays and move network management to the cloud, limiting costly on-premises equipment.

What exactly is software-defined WAN? How will that change how we build and manage the WAN?

Nick Lippis: At the last Open Networking User Group (ONUG), the software-defined WAN was in the top three important use cases. By the time this ONUG came around (six months later), quite a few companies came out of nowhere with [SDN-WAN technology]. There's vIPtela, CloudGenix, Glue Networks, Pertino Networks, and Cisco has initiated its Intelligent WAN (IWAN) program.

At this ONUG we had use cases from Cigna, Pfizer, JP Morgan and The Gap Inc. They were all looking at redesigning their branch offices. The consensus is that the model that we've been using to build out branch office networks is dead. We have been contorting applications that are written for cloud and mobile to fit underneath that. This caused huge pain points for all these organizations in terms of inflexibility, high cost and lack of agility. Software-defined WAN is an overlay on top of WAN infrastructure that gives a lot more flexibility and mitigates those pain points.

With SDN-WAN, you abstract the physical topology of the network, like the MPLS and broadband connections, and then you tunnel between points on that infrastructure. The beauty is that you can have an AT&T transport service, Verizon transport, Level 3 transport -- all of that gets abstracted. And then there is an orchestration model to ease the burden of managing that infrastructure.

Glue networks is focused on the orchestration piece, vIPtela has focused on the overlay piece with a controller aspect; Cisco is going to do the entire stack; Pertino is building SDN in the cloud so you can have VPN connectivity between sites with no user/agent software.

But there is a trajectory here. There will be newer approaches where they are trying to take network appliances out of the branch office and put that into private or public cloud and use Ethernet and broadband connectivity for connections into branch offices. Then the equipment that goes into [the branch office] gets simplified over time, so we will see network services be attached on private clouds for branch offices and low-cost connectivity devices in the branch.

About the expert:
Nick Lippis is the co-founder of the Open Networking User Group (ONUG) and he publishes The Lippis Report. Nick is a world-renowned authority on corporate computer networking. He has designed some for the largest computer networks in the world. He has advised many Global 2000 firms on network strategy, architecture, equipment, services and implementation, including Hughes Aerospace, Barclays Bank, Kaiser Permanente, Eastman Kodak Company, Federal Deposit Insurance Corporation (FDIC), Liberty Mutual, Schering-Plough, Sprint, WorldCom, Cisco Systems, Nortel Networks and a wide range of other equipment suppliers and service providers.

This was last published in May 2014

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