So, what is this OVSDB protocol? Obviously, you could just go and read our new Internet draft, but here is the quick summary. While OpenFlow establishes flow state in a switch, there’s a lot more to Open vSwitch – indeed there is more to networking – than just setting up flow (or forwarding) table entries. In Open vSwitch, you can create many virtual switch instances, attach interfaces to those switches, set QOS policies on interfaces, and so on. None of these configuration tasks can be done with OpenFlow, so you need a management/configuration protocol to do them.
The OVSDB protocol has been part of the Open vSwitch implementation for many years. It is essentially a general purpose protocol for interacting with a database, and in Open vSwitch the database in question is a set of tables representing switch configuration data. (Some readers may be familiar with of-config – the OpenFlow config protocol – a more recent effort; we believe that protocol could actually be implemented on top of OVSDB.)„