Protocol-independent forwarding
Research has been ongoing on how a common, consistent, and vendor-independent way consistent with OpenFlow can be defined to ensure packet processing by a flexible switch. The Open Networking Foundation (ONF) proposed the (OF-PI) approach, which was created to express new and existing protocols in the data path.
OF-PI is composed of a set of instructions that are protocol neutral, called the POF-FIS, and the P4 language, which is utilized to express the method in which forwarding of packets should be done by the forwarding plane. P4 and POF-FIS express the supported functionalities in an OpenFlow specification which is revealed as a library module existing on OF-PI. P4/POF modules could be used to express various protocols such as Generic Routing Encapsulation (GRE) and Multiprotocol Label Switching (MPLS).
Here, P4 is used to define the formats of the packet and table structure, and POF-FIS, which is protocol independent, is used to perform actions that are...