Home > Communication Service Provider Solutions > Converged Core > Guides > Dell Technologies 5G Core Validated Design with Oracle and VMware Reference Architecture Guide > CNF design
This section describes the CNF requirements and how CNFs can be onboarded and instantiated in Telco Cloud Platform for 5G Core.
Helm is the default package manager in Kubernetes and is widely used by CNF vendors to simplify container packaging. With Helm charts, dependencies between CNFs are handled in formats that are agreed on by the upstream community, enabling telco operators to consume CNF packages in a declarative and easy-to-operate manner. With proper version management, Helm charts also simplify workload updates and inventory control.
The Helm repository is a required component in the Telco Cloud Platform 5G Core. Production CNF Helm charts must be stored centrally and be accessible by the Tanzu Kubernetes clusters. To reduce the number of management end points, the Helm repository must work seamlessly with container images. A container registry must be capable of supporting both container image and Helm charts. You can use Telco Cloud Automation to change the values being used by Helm charts. For more information, see the VMware Telco Cloud Automation User Guide.
NF Helm charts are uploaded as a catalog offering wrapped around the ETSI-compliant TOSCA YAML (CSAR) descriptor file. The descriptor file includes the structure and composition of the NF and supporting artifacts such as the Helm charts version, provider, and set of preinstantiation jobs. Core NFs have sets of prerequisite configurations on the underlying Kubernetes cluster. Those requirements are also defined in the NF CSAR.
The CSAR extension supports the following features:
You can update CSAR files to reflect changes in CNF requirements or deployment models. CNF developers can update the CSAR package directly in the Telco Cloud Automation designer or use an external continuous integration and continuous deployment (CI/CD) process to maintain and build newer versions of the CSAR package.