Uplink ingress policing is a Quality of Service (QoS) feature within the Nokia Nuage Virtualized Services Platform (VSP). It is an overlay function used to rate-limit traffic entering the virtualized network from a Virtual Machine (VM), container, or gateway. The policy is enforced at the Virtual Port (V-Port) on the Virtualized Routing and Switching (VRS) or Network Services Gateway (NSG). The Nuage VSP manages and applies policies to the overlay network; it does not directly configure or manage the physical underlay network devices. Therefore, stating that this policing can be applied to the underlay is false.

A. It can be applied to the overlay.

This is a true statement. Uplink ingress policing is fundamentally an overlay QoS policy enforced at the edge of the virtual network to control traffic entering it.

C. VSD raises an alarm when the policing threshold is crossed.

This is a true statement. The Nuage platform is designed to monitor policy enforcement. When a policer drops packets due to exceeding the configured rate, events are generated which can trigger alarms in the VSD for operational visibility.

D. The policer can be configured by enterprise admin.

This is a true statement. The Nuage VSP uses a role-based access control model where an Enterprise Administrator has the permissions to define and apply network policies, including QoS and policers, for their specific tenant/enterprise.

1. Nokia Nuage Networks Virtualized Services Platform Fundamentals Guide, Release 20.10.R1, Section 2.2.1 "Overlay network" and 2.2.2 "Underlay network". This document clearly distinguishes between the overlay, where Nuage VSP applies service policies, and the underlay, which provides basic IP connectivity. It establishes that QoS is an overlay service function.

2. Nokia Nuage Networks VSP User Guide, Release 20.10.R1, Section: "Managing rate limiting". This section details how administrators can create ingress and egress QoS policies (policers) and apply them to various overlay objects like domains, zones, or subnets. This confirms the policy is applied to the overlay.

3. Nokia Nuage Networks VSP User Guide, Release 20.10.R1, Section: "User roles and permissions". This section describes the capabilities of the "Enterprise Admin" role, which includes the creation and management of all policies, including QoS policies, for their designated enterprise. This confirms that an enterprise admin can configure the policer.

4. Nokia Nuage Networks Virtualized Services Assurance Platform User Guide, Release 20.10.R1, Section: "Alarms". This guide explains how the platform generates alarms based on events and threshold crossings within the network. A policer dropping traffic is a monitored event that can be configured to raise an alarm, confirming the validity of this function.