There are two major approaches that are in view for packet forwarding beyond OpenFlow:
- Protocol Oblivious Forwarding (POF)
- Programming protocol-independent packet processors (P4)
This is a recent technology proposed by Huawei Technologies that supports a protocol-independent data plane in SDN. In POF, the data-plane forwarding element does not require prior knowledge of the header structure of the protocol packet it is to traverse; rather, it can be configured by the control plane with the offsets in the configuration phase.
At runtime, the offsets are extracted by the Forwarding Elements (FE) and lookup from the flow table is done, followed by execution of the vital instructions.
This allows the forwarding element to support new protocols easily with no need to modify its hardware as well as wired protocols, such as between controller and switch.
POF is completely unaware of the protocols running on the data plane, such as the IP, TCP, and Ethernet...