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Introduction to Orchestration with Paragon Active Assurance

Overview

The figure below presents Paragon Active Assurance in relation to the ETSI NFV reference architecture.

The Virtual Test Agent (vTA) in Paragon Active Assurance is a Virtual Network Function (VNF) deployed on a hypervisor such as KVM or VMware ESXi. A vTA has support for retrieving day-0 configuration to reach Control Center and the interface configuration via cloud-init user data.

Test Agent VNF instantiation is typically made by a third-party NFVO or service orchestrator as a request to the Generic VNF Manager (G-VNFM). Paragon Active Assurance relies on a G-VNFM for onboarding and instantiation. Control Center implements the role of a Specific VNF Manager (S-VNFM), as well as the role of an Element Manager (EM) for the vTAs. The Paragon Active Assurance vTA corresponds to a VNF.

Furthermore, the NFVO or service orchestrator will connect the vTA VNF into the service chain at the relevant connection points. Where and how to deploy the vTA VNF, and how to connect it into the service chain, should be described in the Network Service Descriptor (NSD).

In other words, Paragon Active Assurance is agnostic to where the vTAs are deployed and connected. However, once they have been spun up, the vTAs will automatically connect to Control Center for remote management and will wait for instructions on what types of measurements to perform.

The service orchestrator is typically the component which initiates a test session using the Control Center API and which retrieves the aggregated measurement results from the Test Agent activities. Active monitoring sessions, too, are typically initiated by the service orchestrator via the Control Center API. As the monitoring sessions during the assurance phase is controlled by the service orchestrator, changing or deleting a service will also automatically change or delete the corresponding monitor. Performance KPIs may be retrieved by third-party Performance Management Systems, while events, once triggered by threshold violations set in the Control Center, can be sent to third-party Fault Management systems.

To summarize, the figure below shows how Paragon Active Assurance interacts with other third-party systems in the OSS landscape.

  • NFVO/Service Orchestrator: Instructs the VNF Manager to deploy the vTAs and configure Paragon Active Assurance into the service chain. Once the service has been activated, the orchestrator uses the API towards Control Center to trigger service activation tests and retrieve pass/fail results. If the tests pass, the orchestrator will use the API towards Control Center to start active monitoring of the service. KPIs from the monitoring are retrieved continuously either by the orchestrator or by a separate Performance Management platform.
  • Control Center (G-VNF Manager): Deploys, scales, and terminates the vTA as instructed by the NFVO or service orchestrator.
  • Performance Management system or Service Quality Management system: Reads KPIs from active monitoring via the Control Center API.
  • Fault Management system: Receives NETCONF, SNMP, or email notifications from Control Center if SLAs are violated.

Definitions of Paragon Active Assurance Concepts

  • Test Agents: The components that perform measurements (for tests as well as monitors) in a Paragon Active Assurance system. Test Agents consist of software with the ability to generate, receive, and analyze real network traffic.
    • The kind of Test Agent discussed in this document is the Virtual Test Agent (vTA), a virtual network function (VNF) deployed on a hypervisor. Other types of Test Agent also exist.
  • Measurement types: There are two basic types of measurement in Paragon Active Assurance, tests and monitors.
    • Test: A test consists of one or several steps, each of which has a specified, finite duration. Steps are executed sequentially. Each step may entail running multiple tasks concurrently.
    • Monitor: A monitor does not have a specified duration but executes indefinitely. Like a step in a test, a monitor may execute multiple concurrent tasks.
  • Template: When Paragon Active Assurance is controlled by an orchestrator, tests and monitors are always executed by means of templates in which the test or monitor is defined. Parameter settings can be passed as inputs to the template at runtime.

Work Flow for Automation

Design Time

At design time, you prepare measurements by creating templates for tests and monitors in Paragon Active Assurance. How to do that is covered in the chapter Setting Up Test and Monitor Templates.

Runtime

At runtime, you set up your devices and perform the actual measurements.

There is also the possibility of pushing SSH keys to Test Agents to enable logging in to the Test Agents via SSH. The details are covered in the chapter Examples: SSH Keys.