Halia: Toward Full-Coverage Network Function Offloading in the Data Plane

Offloading network functions (NFs) to data plane switches brings remarkable performance benefits. In such offloading, NFs are required to process all the flows of interest (i.e., full coverage) to preserve the quality of services. However, existing solutions fail to guarantee full coverage for NFs. Thus, NFs may miss some essential flows, leading to accuracy drops. In this paper, we propose Halia, a framework that makes NF offloading decisions while ensuring full coverage for NFs. Specifically, Halia formulates the problem of NF offloading as an optimization problem. It encodes the requirement of full coverage as a constraint. Thus, its decisions activate enough NF instances in the substrate network to achieve full coverage.. We have implemented Halia and conducted experiments under multiple realistic network topologies to evaluate Halia. The experimental results indicate that compared to existing solutions, Halia achieves full coverage and high scalability in large-scale networks.