ling on/off, or do nothing. In network management, control-loop systems play a vital role in delivering operational cost savings. Control-loop automation can be categorized into open or closed-loop systems. Open-loop systems capture telemetry and diagnostics information from the underlying cloud infrastructure (e.g., syslog, simple network management protocol (SNMP), fault, and network performance man- agement events), perform a set of analytics, and provide reporting or alarms to the operations team. Closed-loop systems continuously monitor the system for fault, performance, security, etc. related problems and compute a set of signatures based on the detected anomalous condition. A policy engine then interprets these signatures and appropriate corrective actions are recommended to repair the system. Once the system has been repaired, a monitoring application checks the status to see whether the system responded to alleviate the detected problem. The goal is to attain zero downtime or minimal interruptions. An implementation of the control-loop system in ONAP is shown in Figure 8.13. CLAMP, which stands for Control Loop Automation Management Platform [Gil16], includes three basic compo- nents. (a) A portal, which is essentially a web browser that enables authentication, construction, configuration, certification, testing, governance approval, and distribution of control loop templates. (b) A workflow engine that enables translation of the design template into an executable data model. The workflow engine communicates with ONAP through a set of well-defined ONAP-specified APIs. (c) A monitoring dashboard that enables telemetry data capture relevant to the performance of the control loop, status update, and diagnosis of failures. 8.3.4.1 Closed-Loop Modeling and Template Design During the design phase, models for network functions virtualization (NFV) and ONAP platform elements are retrieved from a catalog and composed to create a service chain. This facilitates rapid Network Data and Optimization Event Subscriptio