As the industry prepares to move from VNFs to CNFs, Kubernetes extensions can deliver a unified automation framework across the telco cloud stack. Project Nephio aims to achieve this.
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Summary
Increasingly, Kubernetes (K8s) is being successfully used for automating container management workflows in enterprise IT environments. The open-source software promises similar benefits to telcos as the industry shifts toward cloud-native network functions (CNFs). Automation and orchestration are not new to the world of communications service providers (CSPs), yet there are gaps that K8s can help to bridge. With project Nephio, K8s extensions can deliver a unified automation framework across the telco cloud stack.
To date, telcos have struggled with the automation of virtualized network functions (VNFs). Challenges include fragmentation in the tools and approaches to automation of virtualized infrastructure, network function resource, and network function configuration.
As the industry prepares to move from VNFs to CNFs, some participants view Nephio with great enthusiasm while others are skeptical. Our recent report Nephio: Evolving K8s to Answer Telco’s Automation Challenges (see Further reading) explores Nephio’s ability to successfully lead the industry toward closed-loop and intent-driven network automations of cloud-native networks.
Fragmentation limited the automation of NFV
Over the last 10 years, telecom network vendors have created VNFs to replace or complement large parts of their traditional physical network function portfolio (mobile core, IMS, etc.). The isolation between the physical and the virtualized network elements introduced new requirements for management and orchestration. The standards development organization, ETSI, defined an architectural framework for network functions virtualization (NFV), introducing hierarchies of management systems to support infrastructure (NFVI), VNFs, and network service orchestration.
This layered structure required the creation of relationships within as well as between these layers. There was a lack of commonality in the structure and packaging formats of VNFs. Vendors started delivering highly customized and specific implementations of NFV through their own VNF packages that consisted of VNF descriptors (VNFD), software images for virtual machines (VMs), and other artifact resources such as scripts and configuration files.
The orchestration packages or tools, often consisting of a virtual network functions manager (VNFM) and element management systems (EMS)/network management systems (NMS), therefore, were also customized and tweaked to read these vendor-specific VNF packages.
Telcos ended up with a 1:1 dependency between network functions and their management systems. That meant if a telco deploys 5G core functions from two different vendors, it also needed two separate network management systems (VNFM/EMS).
Nephio extends Kubernetes for a unified automation framework across the telco cloud stack
Arguably, telcos have not benefited from Kubernetes (K8s) to the extent that has been achieved in some enterprise environments. Generally, telcos are using K8s in its basic form, as a tool for container management and orchestration. However, K8s can be used to deliver and simplify telcos’ automation challenges in cloud-native environments. This is achieved by extending base K8s with custom resource definitions (CRDs) and operators.
This is where project Nephio comes in. Nephio’s focus is on reducing fragmentation in approaches to the automation of cloud infrastructure, network function resource, and network function configuration lifecycle management and, therefore, delivering the agility and cost benefits of cloudification to the industry. It does so by making K8s a de facto choice for managing and automating networks.
Nephio uses custom resources and K8s operators to address the existing challenges arising from the complexity of using so-called infrastructure as code (e.g., Helm charts) to provision cloud resources, as well as the multiplicity of vendor-specific templates and models. It emphasizes that specific management and orchestration tasks of network operations are delivered by the underlying K8s platform through defined CRDs and operators.
At present, these specific tasks are performed by management and orchestration (MANO) systems, particularly VNFM and EMS/NMS. As shown in Figure 1, the proposed architecture replaces these with Nephio, where a collection of CRDs and operators simplify CNF deployments and cloud-native operations. This use of K8s resources and container management tools is enabling Nephio to implement an integrated, continuous in-band, closed-loop monitoring of the network functions, which is missing in today’s out-of-band monitoring with NFVO and other management systems.
Figure 1: Cloud-native automation with Nephio
Source: Omdia, Nephio
Conclusion
As we outline in our recent report Nephio: Evolving K8s to Answer Telco’s Automation Challenges (see Further reading), Omdia believes that industry confidence in Nephio has grown steadily since the launch of the project last year. Many companies from the telco ecosystem have joined and contributed to the project to speed up the shift toward cloud-native networking. Its focus on reducing fragmentation in approaches to the automation of cloud infrastructure, network function resources, and network function configuration and lifecycle management presents a great opportunity to all members of the telecom ecosystem.
Appendix
Further reading
Nephio: Evolving K8s to Answer Telco’s Automation Challenges (March 2023)
The Promise of Nephio: Clean Up Telecom’s Cloud-Native Mess and Melt the “Snowflakes” (July 2022)
Author
Inderpreet Kaur, Senior Analyst, Telco Cloud and Network Automation
