Huawei Huawei Huawei Apstra This document outlines the applicability of Abstraction and Control of Traffic Engineered Networks (ACTN) to VPN with the integration of Packet and Optical Networks (POI). It also identifies a number of scenarios where the integration of packet and optical networks is necessary to support VPN service requirements. The role of optical underlay tunnels in the POI is to support certain applications that require a hard isolation with strict deterministic latency and guaranteed constant bandwidth.