Big Switch is a company that is synonymous with Software Defined Networking (SDN), but until today, the company did not have any publicly available commercial offerings.
The CEO and Co-Founder of Big Switch is none other than Guido Appenzeller, the former Stanford Professor that helped to usher in the SDN revolution with the OpenFlow protocol. OpenFlow alone is not enough to enable SDN. OpenFlow also requires switches and controllers, which is now what Big Switch is offering publicly with the Big Virtual Switch and the Big Network Controller products. Additionally Big Switch is providing SDN visibility with the new Big Tap solution.
At the core of Big Network controller is the open source Floodlight controllerthat provides a common network abstraction for the entire network.
Appenzeller explained to EnterpriseNetworkingPlanet that the Big Network Controller will always be based on the latest version of the open source Floodlight controller.
“The enterprise version that is the Big Network Controller adds a lot of functionality that is wrapped around Floodlight,” Appenzeller said.
For example, Big Network Controller has features for uptime high-availability and multiple node deployment tools and capabilities. In contrast, Floodlight is just a single node controller.
“No customer in their right mind would deploy just a single node, at least you’d want two nodes for failover and possibly more nodes for scale-out,” Appenzeller said.
Appenzeller stressed however that the commercial Big Network Controller is still compatible with the same Java modules and APIs that power the open source Floodlight controller. So if a developer had built an application to run on top of Floodlight, that same application will be able to run on top of the Big Network Controller.
The OpenFlow protocol itself which help to enable SDN is now at the 1.3.x version that was announced in May, though that’s not what Big Switch is supporting with its commercial release.
“In our current version we only use OpenFlow 1.0 and the reason is very simple,” Appenzeller said. “We currently don’t have any switches from our partner ecosystem, physical or virtual that supports other versions.”
He noted that changes implemented in the OpenFlow 1.1 protocol and later, include a multi-table support feature that requires a driver for a given switch within the controller. Over time, though Big Switch could implement support for other versions of OpenFlow as hardware support grows.
In a traditional flat network, VLANs are the method by which network administrators have typically attempted to segment their networks. A restriction of VLANs is that networks are limited to only 4096 tagged VLANs, which is not an issue when it comes to SDN.
The Big Network approach takes into account the fact that enterprises today use VLANs and enables their continued used with an overlay.
“Our controller fully supports working with external networks that are not OpenFlow enabled, including VLANs,” Appenzeller explained.
If an enterprise has an existing VLAN and they want to migrate it to OpenFlow, it can be done on a host by host basis. Physical and hypervisor switches can be taken together into a Big Switch Virtual Network Segment, which is the Big Switch term for what used to be known as VLANs. Inside that Virtual Network Segment, the network administrator can configure the controller such that any packets that come in on a given port with a certain VLAN tag can then be mapped to a Virtual Network Segment inside of the Big Switch Controller.
The Big Switch system can work in two different modes depending on the OpenFlow support that is available on the underlying network switches. For network segments that don’t support OpenFlow, Big Switch operates an overlay that leverages whatever tunneling capabilities are available on the switching infrastructure.
One overlay approach that Big Switch does not support today is VXLAN. VXLAN is a standards effort led by VMware and Citrix to provide a Layer 2 overlay for virtual networking. In Appenzeller’s view, today there just isn’t enough broad support for VXLAN on physical switches. However he does expect that situation to change and for Big Switch to support VXLAN in a future release. He had good reason to be optimistic about VXLAN support as well.
“The main developer of VXLAN from VMware now works for us,” Appenzeller said. “So we think we’re in very good shape there.”
In addition to the controller and the virtual switch, Big Switch is also rolling out a network monitoring capability called Big Tap.
“Big Tap takes standard OpenFlow enabled switches and creates a network monitoring fabric of all the monitoring and SPAN ports to dynamically filter, replicate and deliver traffic to the all the necessary downstream performance monitoring and security appliances,” Jason Matlof, VP of Marketing said.
The Big Tap product is one that was born out of the Big Switch private beta which has been ongoing for the last 18 months, according to Appenzeller. That long beta period had a significant impact on what Big Switch is now delivering as commercial products.
“The beta period really helped us to get the product stable, there were a lot of things that we had learned at Stanford but there were still many things that we had to figure out in real deployments,” Appenzeller said.