There has been a lot of hype concerning software defined networks (SDN) and OpenFlow. What does SDN mean for you, and how should enterprises prepare for the coming changes in network architectures?
SDN promises to make the network more flexible, easier to manage, and programmable (for a good SDN overview see "Five needs driving SDNs"). But obviously you have to continue to judge changes in network design based on performance, reliability, security, management and operational costs. This argues for incremental changes rather than revolutionary ones.
Leading-edge users of SDN and OpenFlow have focused on high-performance, hyperscale data centers (e.g. Google, Facebook, Amazon, eBay), network partitioning (universities) and ultra-high performance network tuning (financial sector). Organizations that have the need to optimize one or more critical applications to their network (including CSPs and cloud providers) should investigate the capabilities of SDN and OpenFlow.
For most other IT shops, the initial focus of SDN implementations will be in their datacenter. It is in the datacenter where the network has been most impacted by new requirements brought by server virtualization.
My recommendation is to ask your leading suppliers to keep you informed about key SDN developments and track the standards community. Test SDN capabilities in pilot projects to assess the impact on network reliability. Review SDN use cases that match your shop's requirements.
It is very early days for SDN. Those organizations with significant IT resources and top talent (Google, Facebook, et al.) are taking the SDN plunge. Mainstream IT organizations will be wise to wait a bit as the bleeding edge shakes out. It will take a few years for SDN applications (e.g. management scripts) and best practices to become available. SDN technology advances are moving fast and will require a significant learning curve -- one that most network managers and the VAR/SI channel have not yet experienced.
SDN will change the way that networks are architected, programmed and managed. And the network will become more agile, flexible and cost less to operate. However, like many IT advances, SDN will take time to mature. Given the plethora of choices, IT shops should proceed at a measured pace on their journey to SDN.