What is Software Defined Networking? or What is SDN?
This is the first in a series of thirteen blogs that are designed to help IT organizations on their path to Software Defined Networking (SDN) adoption. This blog will define what SDN is and will briefly discuss the relationship between SDN and network virtualization.
The SDN definition that I will use is based on the Open Networking Foundation’s (ONF) definition of SDN. The ONF definition states that within an SDN, the control and data planes are decoupled, network intelligence and state are logically centralized and the underlying network infrastructure is abstracted from the applications. I want to add to that definition that within an SDN there is a programmatic interface into the control function.
IT organizations have been implementing varying forms of network virtualization for well over a decade. One form of network virtualization that has been used in production networks since the mid to late 1990s is Virtual LANs (VLANs). VLANs use a 12 bit identifier to partition an Ethernet network into as many as 4,096 broadcast domains. A more recently developed form of network virtualization is network overlays using technologies such as VXLAN, NVGRE and STT. The primary use case for this form of network virtualization is to enable VM migration. While that is an important use case, an SDN can enable VM migration and it can also solve other problems.
My next blog will discuss the drivers of SDN as well as the primary use cases and benefits.
Click below to watch Part 1 of the SDN Journey – Note: You must be an SDNCentral member to watch. Login to SDNCentral or register for free.