It's time for a software-defined networking architecture

Prepare for the SDN surge

You should get ready for SDN even if your company hasn't made the decision yet.

To start, evaluate how a software-defined networking architecture changes staffing and training needs, check SDN's compatibility with existing hardware and processes, and consider how cloud will fit in with future plans.

Software-defined networks bring up an immediate personnel issue, Laliberte said. Who on the IT side is going to "own" and run the network virtualization technology -- the network team or the virtualization team? If the latter, there needs to be tight coordination between them.

The more well-known network virtualization technologies, VMware's NSX and Microsoft's Hyper-V Network Virtualization, are coming from the server virtualization vendors, Laliberte said. Others, such as network vendors, may take a network-centric approach.

From an infrastructure perspective, most network virtualization technologies should work with existing network hardware. The one drawback is the limited insight between the physical and virtual network; this could potentially diminish performance if the virtual network links are overprovisioned on physical links, Laliberte said.

Vendors need ecosystems to drive visibility between the virtual and physical network, as well as connect to the physical network, Laliberte added. VMware's NSX is an example. "We have seen this movie before with server virtualization and Distributed Resource Scheduler. Now we need network DRS," he said.

One of the potential advantages of SDN is faster network provisioning, which helps drive faster application deployments. That, in turn, should accelerate revenue from those applications, Laliberte said. Most importantly, it should eliminate much of the time-consuming activities of network operations.

Is SDN the right move?

ESG's research shows that organizations complain about the time needed to provision network services, among such lesser challenges as the ability to scale rapidly, network latency, lack of flexibility to support virtual environments, inadequate capacity and poor security for multi-tenancy.

Organizations should understand and evaluate current processes to determine how long each one takes relative to potential improvements under SDN, Laliberte said.

"SDN is more than just network provisioning, it is also about network services provisioning," he said. That includes security (IDS, IPS and firewall), WAN optimization, application delivery controllers, and other components that need to stay with an application or virtual machine -- even if it moves from server to server or from data center to data center.

A shift to SDN may require the full focus of a networking team, Forrester's Kindness said. "Typically these are people that are rewarded for putting out fires; they will need to have their rewards based more on efficiency and speed [to move] to SDN."

Kindness suggests that data center leaders develop guidelines and guardrails regarding who programs the network, set criteria for moving applications, set bandwidth policy issues and so on; it isn't just a matter of suddenly switching over to SDN. The benefits of a SDN architecture may be elusive without proper planning, he said. Furthermore, IT shops need to consider future moves to hosted services in a redesign, so they can facilitate evolution beyond SDN.

Companies typically start moving to cloud at the same time that they focus more on IT as a service, with robust internal chargeback mechanisms, IDC's Casemore said. Somewhere in the process, you need to think about network infrastructure, and that is where an SDN discussion fits in.

Organizations will approach SDN differently depending on their maturity and cloud orientation. "If you are a cloud-type organization that has moved or is moving toward cloud orchestration and OpenStack, you will probably move in that direction first," Casemore said. By contrast, enterprises that aren't actively moving in that direction are probably siloed and thus less ready to take on network virtualization challenges. "Many organizations will try to push off these decisions because they aren't feeling the pain acutely enough, because of political reasons or lack of the right skill sets," he said.

About the author:
Alan R. Earls is a Boston-area freelance writer focused on business and technology.