Use zero touch provisioning (ZTP) to provision distributed units at new edge sites in a disconnected environment. The workflow starts when the site is connected to the network and ends with the CNF workload deployed and running on the site nodes.

ZTP for RAN deployments is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see https://access.redhat.com/support/offerings/techpreview/.

Provisioning edge sites at scale

Telco edge computing presents extraordinary challenges with managing hundreds to tens of thousands of clusters in hundreds of thousands of locations. These challenges require fully-automated management solutions with, as closely as possible, zero human interaction.

Zero touch provisioning (ZTP) allows you to provision new edge sites with declarative configurations of bare-metal equipment at remote sites. Template or overlay configurations install OpenShift Container Platform features that are required for CNF workloads. End-to-end functional test suites are used to verify CNF related features. All configurations are declarative in nature.

You start the workflow by creating declarative configurations for ISO images that are delivered to the edge nodes to begin the installation process. The images are used to repeatedly provision large numbers of nodes efficiently and quickly, allowing you keep up with requirements from the field for far edge nodes.

Service providers are deploying a more distributed mobile network architecture allowed by the modular functional framework defined for 5G. This allows service providers to move from appliance-based radio access networks (RAN) to open cloud RAN architecture, gaining flexibility and agility in delivering services to end users.

The following diagram shows how ZTP works within a far edge framework.

ZTP in a far edge framework

The GitOps approach

ZTP uses the GitOps deployment set of practices for infrastructure deployment that allows developers to perform tasks that would otherwise fall under the purview of IT operations. GitOps achieves these tasks using declarative specifications stored in Git repositories, such as YAML files and other defined patterns, that provide a framework for deploying the infrastructure. The declarative output is leveraged by the Open Cluster Manager for multisite deployment.

One of the motivators for a GitOps approach is the requirement for reliability at scale. This is a significant challenge that GitOps helps solve.

GitOps addresses the reliability issue by providing traceability, RBAC, and a single source of truth for the desired state of each site. Scale issues are addressed by GitOps providing structure, tooling, and event driven operations through webhooks.

About ZTP and distributed units on single nodes

You can install a distributed unit (DU) on a single node at scale with Red Hat Advanced Cluster Management (RHACM) (ACM) using the assisted installer (AI) and the policy generator with core-reduction technology enabled. The DU installation is done using zero touch provisioning (ZTP) in a disconnected environment.

ACM manages clusters in a hub and spoke architecture, where a single hub cluster manages many spoke clusters. ACM applies radio access network (RAN) policies from predefined custom resources (CRs). Hub clusters running ACM provision and deploy the spoke clusters using ZTP and AI. DU installation follows the AI installation of OpenShift Container Platform on a single node.

The AI service handles provisioning of OpenShift Container Platform on single nodes running on bare metal. ACM ships with and deploys the assisted installer when the MultiClusterHub custom resource is installed.

With ZTP and AI, you can provision OpenShift Container Platform single nodes to run your DUs at scale. A high level overview of ZTP for distributed units in a disconnected environment is as follows:

  • A hub cluster running ACM manages a disconnected internal registry that mirrors the OpenShift Container Platform release images. The internal registry is used to provision the spoke single nodes.

  • You manage the bare-metal host machines for your DUs in an inventory file that uses YAML for formatting. You store the inventory file in a Git repository.

  • You ins