As per Wikipedia, “Open vSwitch, sometimes abbreviated as OVS, is a production-quality open-source implementation of a distributed virtual multilayer switch. The main purpose of Open vSwitch is to provide a switching stack for hardware virtualization environments, while supporting multiple protocols and standards used in computer networks”
Open vSwitch is software based solution which resolves the problems of network separation with in virtualization environment. It also provides fast data path in kernel space with OPENFLOW implementation.