Prioritization and offloading in P4 switch integrated with NFV

The architecture of integrating Software Defined Networking (SDN) with Network Function Virtualization (NFV) is excellent because the former virtualizes the control plane, and the latter virtualizes the data plane. As Programming Protocol-independent Packet Processors (P4) become popular, the architecture integrating SDN with NFV may shift from traditional switches to P4 switches. In this architecture, which integrates P4 switch and NFV (P4 + NFV), network functions can be provided in both P4 switches (PNF) and NFV (VNF). Thus, to minimize packet delay, an offloading problem between P4 switches and NFV in this P4 + NFV should be addressed. This paper tackles this offloading problem and figures out the prioritization mechanism between newly arriving packets and packets that require VNF for minimizing packet delay. We model and analyze the P4 + NFV architecture using an M/M/1 queuing model with non-preemptive priority. Also, we propose an optimization solution based on gradient descent to find the optimal offloading probability of going to VNF. Results show that optimal offloading from P4 switch to NFV can reduce the average packet delay from 13.74 to 40.73%, when packets requiring VNF are given higher priority than newly arriving packets.