VMware helped to lead the revolution that has transformed the data center server space with virtual nodes of compute server infrastructure. Now VMware wants to lead the way in virtualizing networking. It’s a movement that is aligned with the newly emerging trend of software defined networking (SDN) that enables programmable networks abstracting networking hardware.
VMware’s Software Defined Data Center
Allwyn Sequeira, vice president and CTO of Security and Networking at VMware explained to Enterprise Networking Planet that while it might take two minutes to set up a virtual machine (VM) it could take an additional five days in traditional data center deployment to set up the network to support and enable that VM. To get around that, Sequeira is advocating for VMware’s Software Defined Data Center, which is a new architectural approach that virtualizes the network elements like firewalls and load balancers.
“The whole idea is about delivering a scale-out elastic architecture that is available to apps on-demand,” Sequeira said. “You are freeing yourself from the tyranny of having to buy hardware.”
In Sequeira’s view, it’s not possible to scale physical networking hardware to meet the on-demand needs of modern virtualized applications. From a product and technology perspective, the Software Defined Data Center architecture involves applications and specification available now, as well as work that is coming. With server virtualization there is now the concept of one vSwitch per host and, in that context, a VLAN is how VMs are networked. VLANs traditionally have been limited in their ability to stretch across data center domains, which is where the VXLAN standard comes into play.
The VXLAN specification was initially proposed in September of 2011, and is a multi-vendor effort that includes VMware along with Cisco, Arista Networks, Citrix and Red Hat. The basic idea behind VXLAN is to have a Layer 2 abstraction for virtual machines so they are not restricted to a particular LAN boundary.
“VXLAN is the basis for us untethering ourselves from current network limitations,” Sequeira said. “VXLAN is what enables end-to-end elasticity in the data center and allows you to build a software defined network.”
VXLAN abstracts the VLAN from the underlying physical network and it also supports multi-tenancy. VXLAN is not a finalized industry standard. It is available as an Internet Engineering Task Force (IETF) draft standard known as NV-03 (network virtualization over Layer 3).
VMware vs. OpenFlow
For Sequeira, he now sees two views of the SDN world. One is the VMware type approach with vSwitch and VXLAN and the other is OpenFlow. OpenFlow is an open source protocol for SDN that is also gaining in interest and popularity.
“I want the equivalent of a LAN across a data center and that’s what VXLAN does,” Sequeira said. “The VXLAN overlay combined with what we have with vSwitch and vCloud networking is what we believe to be the most prevalent form of SDN in the world today.”
When it comes to OpenFlow, in Sequeira’s view there are a set of vendors that are now building monolithic stacks on top of the OpenFlow protocol, trying to establish control points. As such he expects that SDN silos will emerge over time that will require some form of federation to connect together.
“For us, SDN is a natural extension of our current product lines, extending what we already have for a VMware domain,” Sequeira said. “When do we see a world when there is a VMware SDN working with an OpenFlow SDN? I don’t think, that’s in the cards.”