Following the recent VMware announcement regarding their intent to acquire Nicira, there has been a lot of talk about Software Defined Networking (SDN) and how it is a “game changer.” At a high level, SDN is a technology and standardization that separates the network control plane from the forwarding of frames/packets. This enables centralized control and management of a network infrastructure, which is the final step in achieving true agility through cloud computing. With SDN in place, organizations can dynamically provision compute, storage and network resources without manual intervention or time delays.
Nicira brings three key features to the virtual networking arena. The first is a Network Virtualization Platform (NVP) Controller Cluster, which is a highly available, distributed system that manages all the virtualized network components and connections, and runs on COTS servers. The second is an Open vSwitch (OVS) that acts like a shim between the hypervisor and the VM network. In Citrix and Linux based KVM deployments, OVS is now part of the hypervisor. For VMware architectures however, the OVS sits between traditional VM networking (vSwitch, Distributed vSwitch or 1000v) and the hypervisor, which presents limitations and significant performance differences over Citrix and KVM deployments. The third is a proprietary, highly efficient, tunneling protocol. The combination of these three key features brings amazing potential to the network agility discussion, as it can eliminate the restrictions of VLANS in large environments, as well as increase mobility and agility for vMotion, enable live migration events, positively impact disaster recovery\continuity of operations capabilities and provide multi data center high availability designs.
The potential is enormous – as validated by Oracle’s purchase of Xsigo – but there are also downsides. SDN requires a shift in an organization’s IT mindset in order to even consider, much less implement this type of technology. IT designers and operators must fully understand the technology and be able to think differently about how to solve problems to truly realize the potential of SDN. There are many potential design pitfalls that must be navigated as well, and a few iterations of integration that need to occur. Knowing that IT is, by nature (and sometimes necessity) risk averse, I question the rapid adoption of this technology. That said, if you consider the recent moves by industry leaders VMware and Oracle, I think the market is definitely on the right path to broader adoption.