Department of Electronic, Electrical and Computer Engineering Department of Computer Science and Engineering Electronics and Telecommunications Research Institute Huawei Huawei This document defines a YANG data model for configuring security policy rules on Network Security Functions (NSF) in the Interface to Network Security Functions (I2NSF) framework. The YANG data model in this document is for the NSF-Facing Interface between a Security Controller and NSFs in the I2NSF framework. It is built on the basis of the YANG data model in the I2NSF Capability YANG Data Model document for the I2NSF framework.