Enhancing the Open Virtual Switch

Virtualization is placing a great amount of stress on traditional networking infrastructure, so it's no wonder enterprises are looking to add virtual switching as well. Common formats like the Open Virtual Switch are seen as efficient means to incorporate various virtual server and storage platforms into a single architecture. And with firms like Solarflare adding OVS hardware acceleration to their adapter lines, integrating multiple layers of switching is becoming the norm, rather than the exception. Tolley explains what is to be gained by adopting an open platform.

Cole: Recent research suggests that even enterprises that haven't deployed 10GbE or 4G Fibre Channel are not concerned as much about bandwidth in virtual environments as they are about integrating server, storage, networking and virtual resources. How does the Open Virtual Switch format help in that regard?

Tolley: The first point to note is that the 10G switch-to-server interconnect market is growing over 100 percent each year. The Dell'Oro Group counted 251,000 10GbE server connections – adapters and mezzanine cards – in 2009 and estimated the market to grow almost ten-fold to over 2 million ports by 2012. The open virtual switch format gives enterprises a common control plane to manage Layer 2 edge switching for both virtual and hardware resources and the virtual servers attached to the edge. In other words, it gives enterprises more control over the network edge as one common network element.

Cole: What advantages does hardware acceleration bring to the OVS environment?

Tolley: Hardware acceleration gives back to applications the network performance they lose when they were virtualized. With the introduction of feature-rich, software-based virtual switches into the hypervisor, it is now possible to virtualize the applications that depend on network features. For example, the entire application-delivery tier of a data center can be virtualized using the Citrix NetScaler product. It's the rich and robust feature set of the OVS environment that makes such deployment scenarios possible. However, the catch is that the data-plane is software-based and without hardware acceleration is bottlenecked. Solarflare accelerates the data-plane while allowing the OVS environment to remain in control of all the flows, essentially allowing the OVS technique to scale.

Cole: It turns out that management of virtual servers is not as simple as early supporters claimed. What assurances can you give that virtual switching won't lead to overly complicated networking environments?

Tolley: Open Virtual switching greatly simplifies the server edge by making significant reductions in complexity. Instead of administering three tiers of switching – the hypervisor vswitch, IOV fabric and the edge Ethernet switch – the administrator would only be required to administer one logic virtual switch, which treats the layers of switching as component parts. This approach also enables the boundary between server administration and network administration to be flexibly defined to suit the existing practices of each organization.