Cloud-Native Intent-driven Network Automation | Nephio

Telco Automation Requirements and Challenges

Telco requirements for successful 5G journey – Telcos need to implement 5G while simultaneously lowering operating costs and improving agility. Zero-touch provisioning of the network and automated ongoing maintenance of that network are necessary to achieve these goals.

Telco challenges – The transition from VNF to CNF and the transition to the public cloud provide opportunities for cost savings and increased agility. To take advantage of this, telcos must meet the challenges of managing large numbers of sites, zero-touch automation with a human-free control loop, optimization of scarce edge resources, and addressing the limitations of legacy out-of-band network automation.

Automation industry gap – Having multiple automation control planes for different types of infrastructure and different types of network functions makes it impossible to provide interconnected automations that maintain consistency across layers. It also makes it impossible to automatically adapt interrelated layers when one of them changes. There is need to consolidate automation control planes and bring all the declarative, active reconciliation benefits to the entire stack.

Issue with existing Infrastructure-as-Code automation

Complex templates that intermingle code and data are exceptionally difficult to test and maintain. Also, because templates generate manifests as output, you can’t edit those manifests afterward (they’ll be overwritten next time you run the template). This means every single field in every resource ends up as an input to the templates. The results are massive lists of parameters that are not easily understood.

Conditionally generated config based on those inputs makes intent-based continuous reconciliation difficult or impossible. It also results in debugging issues – you have to backtrack from what is in your cluster through all the conditionals to figure out how to fix a problem. 

Key solution requirements

Below are the three key solution requirements to be considered:

• A cloud native solution, beyond just containerizing to get the cost, scalability, and efficiency benefits of the cloud.
• Separate requirements for workload infrastructure and its implementation to increase the portability of the workloads across platforms.
• Cloud-native network functions should use declarative configuration with active reconciliation.

Nephio: Solution Overview

Nephio is Kubernetes-based intent-driven automation of network functions and the underlying infrastructure that supports those functions. It allows users to express high-level intent, and provides intelligent, declarative automation that can set up the cloud and edge infrastructure, render initial configurations for the network functions, and then deliver those configurations to the right clusters to get the network up and running.

Nephio breaks down the larger problem into two primary areas:

• Kubernetes as a uniform automation control plane in each site to configure all aspects of the distributed cloud and network functions
• An automation framework that leverages Kubernetes declarative, actively-reconciled methodology along with machine-manipulable configuration to tame the complexity of these configurations i.e. extends intent-based automation up the stack through the Kubernetes based automation framework.

Benefits of Nephio Kubernetes Based Cloud Native Automation

Telcos

An open, simple, widely adopted Kubernetes-based cloud-native automation that enables multi-vendor support, faster onboarding, easier lifecycle management, embedded control-loop, active reconciliation, and service assurance — reducing cost by efficiency and agility.

Cloud Providers

A common cloud-based automation framework based on well-proven Kubernetes technology minimizes the levels of custom automation solutions needed for each application. Kubernetes-based automation enables faster development with known technology and assures network functions will deploy and run reliably on top of the Cloud.

Network Function Vendors

A Kubernetes based cloud native automation enables easier multi-vendor integration with cloud providers, makes Network Function onboarding to cloud easier and improves the overall customer experience with simple and reliably integrated cloud native automation.

Nephio Kubernetes as a Uniform Automation Control Plane

Utilizing Kubernetes as the automation control plane at each layer of the stack simplifies the overall automation, and enables declarative management with active reconciliation for the entire stack. 

We can broadly think of three layers in the stack, as shown in below figure 1. 

• Cloud infrastructure
• Workload (network function) resources
• Workload (network function) configuration

Nephio is establishing open, extensible Kubernetes Custom Resource Definition (CRD) models for each layer of the stack, in conformance to the 3GPP & O-RAN standards.

Cloud automation layer

For the cloud automation layer (1), Nephio publishes Kubernetes-based CRDs and operators for each public and private cloud infrastructure automation that is in conformance to industry standards (e.g., O-RAN O2 interface).

These CRDs and operators can make use of existing Kubernetes-based ecosystem projects as pluggable southbound interfaces (e.g., Google Config Connector, AWS Controllers for Kubernetes, and Azure Service Operator), providing an open integration point and more uniform automation across those providers.

Workload resource automation

The workload resource automation area (2) covers the configuration for provisioning network function containers and the requirements those functions have for the node and network fabric. This includes the native Kubernetes primitives and industry extensions such as multi-network Pods, SR-IOV, and similar technologies.

Today, using these effectively requires complex Infrastructure-as-Code templates that are purpose built for specific network functions. Taking a Configuration-as-Data, Kubernetes CRD approach, capturing configuration with well structured schemas, allows development of robust standards-based automation. Nephio’s goal is to achieve this open, simple, and declarative configuration for network function automation.

Workload configuration

For workload configuration (3), Nephio initially provides tooling and libraries to assist vendors with integrating existing Yang and other industry models with Nephio, in conformance to the standards (e.g., 01, 3gpp interfaces specs). 

To fully realize the benefits of cloud native automation, these models will need to migrate to Kubernetes CRDs, as these configurations are intimately tied to those described in workload resource automation (2). Nephio provides the same tooling at every layer, enabling the automation of interrelated configuration between those layers.

Nephio Declarative Automation Framework

The below figure provides an overview of Nephio’s functional components. The previously discussed uniform automation control plane is represented at the bottom of the diagram, shown running on individual site clusters as the “Intent Actuation” layer.

The second part of the solution, the Kubernetes-based automation framework, is the top part of the diagram. These components are shown as running in an “Orchestration Cluster” – a separate Kubernetes cluster for housing the automation framework.

The Nephio automation framework is built on the Google Open Source projects kpt and ConfigSync and implements the Configuration-as-Data approach to configuration management. This enables users to author, review and publish configuration packages which may then be cloned and customized to deploy network functions. This customization can be fully automated, or mix-and-match automated and human-initiated changes without conflicts and without losing the ability to easily upgrade to new versions of the packages.

Nephio Reference Architecture

Nephio produces a reference implementation (as shown in the below Figure) demonstrating Nephio’s mission to “materially simplify the deployment and management of multi-vendor cloud infrastructure and network functions across large scale edge deployments.” This reference implementation leverages existing Kubernetes open source and ecosystem projects, including the Google open source projects kpt and ConfigSync (kpt is already open source; ConfigSync will be open sourced 2H 2022 or earlier).

Nephio Quotes

“The Linux Foundation is pleased to host the Nephio project and we’ve been inspired by the enthusiasm, energy, and participation of the founding members. We see momentum building around open, end-to-end solutions, with Nephio playing a key role helping to overcome industry pain points for cloud infrastructure and network functions alongside the LF Networking, CNCF, and LF Edge project communities,” said Rainy Haiby, CTO Networking, Edge/IoT and Access at Linux Foundation.

 

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“Nephio presents a unique opportunity for CSPs to create a new revenue stream through an edge broker business. Nephio simplifies orchestration and management of both network functions and the underlying infrastructure, along with leveraging Kubernetes automation which is a big plus for the 5G + MEC (multi-access edge computing) era,” said Amar Kapadia, Co-Founder & CEO at Aarna Networks.