Which of the following cannot be monitored by the controller?

The Huawei SD-WAN controller (iMaster NCE-Campus) is designed for network orchestration, policy management, and providing aggregated performance analytics. It monitors application quality, link status, and VPN topology. However, it does not directly collect and process devices' original, raw flow information from technologies like NetStream. This function is offloaded to a dedicated, big data analytics component, iMaster NCE-CampusInsight, which is designed to handle the massive volume of raw telemetry data for deep-dive analysis, fault demarcation, and predictive maintenance. The controller consumes processed, analytical results from CampusInsight rather than the raw data itself.

A. The controller uses Deep Packet Inspection (DPI) to identify applications and provides detailed traffic statistics, which is fundamental for Application-Aware Routing (AAR).
B. Visualizing the VPN topology (e.g., Hub-spoke, Full-mesh) is a core function of the controller for centralized management and monitoring of the network overlay.
D. The controller continuously monitors link traffic, utilization, latency, jitter, and packet loss to make intelligent path selection decisions and ensure service quality.

1. Huawei iMaster NCE-Campus Product Documentation, "Intelligent O&M" Section: This documentation distinguishes the roles of the controller (iMaster NCE-Campus) and the analyzer (iMaster NCE-CampusInsight). It specifies that CampusInsight collects device data, including NetStream flows, for analysis. The controller provides centralized management and control, and displays the results of this analysis. For example, in the "Intelligent O&M" feature description, it states, "iMaster NCE-CampusInsight... collects network data in real time... Through big data analytics and machine learning algorithms, it digitizes user experience on the network." This implies the raw data collection is the role of the analyzer, not the controller.

2. Huawei SD-WAN Solution Description, "Solution Architecture" Chapter: The architecture diagrams for Huawei's SD-WAN solution consistently show the controller (NCE-Campus) and the analyzer (NCE-CampusInsight) as separate components in the management plane. The data flow shows CPEs sending telemetry data (including flow data) to the analyzer, while the controller focuses on policy and configuration exchange with the CPEs. This architectural separation confirms the controller does not handle the original NetStream flows.

3. Huawei CloudCampus Solution V3.1.0 Technical Proposal, Section 3.4 "Intelligent O&M": This document details the O&M capabilities. It states: "iMaster NCE-CampusInsight, the intelligent analysis engine... collects device performance indicators, terminal logs, and NetStream data...". This explicitly assigns the collection of NetStream data to the CampusInsight component, not the primary SD-WAN controller.