Overview of OpenFlow v1.0.0
An OpenFlow-enabled router supports an OpenFlow Client (control plane software), which communicates with an OpenFlow Controller using OpenFlow. The OpenFlow Controller runs on a server or a server cluster. OpenFlow-enabled routers support the abstraction of a flow table, which is manipulated by the OpenFlow Controller. The flow table contains flow entries. Each flow entry represents a flow (that is, packets with a given MAC address, VLAN tag, IP address, or TCP/UDP port, and so on). The flow table is sorted by flow priority, which is defined by the OpenFlow Controller. The highest priority flows are at the top of the flow table.
Incoming packets on an OpenFlow-enabled port are matched (in order of priority) against the flow entries defined for that port by the OpenFlow Controller. If the packet matches a given flow entry, the flow-matching process stops, and the set of actions defined for that flow entry are performed. Packets that do not match any flow entry are dropped by default. The RUCKUS ICX implementation of OpenFlow supports an option to send such packets to the OpenFlow Controller. Refer to Configuring the Default Action.
