How Does SDN Fit Into The Virtual Data Center?
One thing that needs to be cleared up is the definition of Network or Networking Hardware. In the definition of SDN from ONF they discuss the decoupling of the Control and Data Plane with the Data Plane being defined as Network Hardware. Here is where things can get confusing.
What is Network Hardware?
Wikipedia says the following :
“Networking hardware or networking equipment typically refers to devices facilitating the use of a computer network. Typically, this includes gateways, routers, network bridges, switches, hubs, and repeaters. Also, hybrid network devices such as multilayer switches, protocol converters, bridge routers, proxy servers, firewalls, network address translators, multiplexers, network interface controllers, wireless network interface controllers, modems, ISDN terminal adapters, line drivers, wireless access points, networking cables and other related hardware.”
Essentially anything that is not a end system is network hardware. The current reality of SDN is that it tends to mean Programmable Switches when it says Network Hardware. Switches are generally made built on fabrics that allow ports to transmit traffic to and from other ports.
If we were to be true to the current SDN message, we would only look at Programmable Switches. Reality is there are other ways you can create a Data Plane i.e. Network Hardware. One of these ways is using a Network Processor (which I covered in the earlier article on Vyatta).
A Computer with a few (or many) Interfaces and a Network Processor is what a Router is. We can easily see this by looking at the design of Juniper Networks Routers.
This is one of the interesting things I see in the SDN space: Companies that can take advantage of generic hardware and add value. These companies will create more tools for the architects and operators to use when pushing packets.
We plan to cover as many SDN related topics as possible here at SDN Testing, those that exist today and those that will come in the future.