Custom matches

The OpenFlow 1.3 specification defines a fixed set of packet header fields as OXM fields that can be used by the SDN controller to identify which fields in the packet it wants to match in any given flow on a flow table. The header fields defined are a list of well-known and popular protocol fields. The list is not exhaustive. There are still many packet fields that are not covered in the standard set but might be required to solve potential SDN use cases.

The SDN controller now can define one or more abstract match fields (termed custom match) in a flow-table of an instance running in custom pipeline-model when defining the new pipeline