- XenonStack

Overview of ONAP Architecture and Best Practices

What is ONAP?

It’s a project under the governance of the Linux Foundation and founded by AT&T and China Mobile. ONAP stands for Open Network Automation Platform (ONAP) is an initiative created by the combination of the ECOMP and Open-O projects into ONAP, to bring the capabilities for designing, creating, orchestrating and handling of the full lifecycle management of VNF (Virtual Network Functions) or Network functions virtualization (NFV), SDN (Software Defined Networks), and the services that all of these things require.

Note – The primary goal of ONAP is to implement the capabilities needed for orchestration and handling of the full lifecycle management of VNF deployments.

ONAP is the platform that works above the infrastructure layer to automate the network. ONAP allows end-users to connect products and services through the infrastructure. It allows deployments of VNFs and scaling of the network, in a fully automated manner. The high-level architecture of ONAP consists of different software subsystems that broadly divided into a design-time environment, and execution time environment to execute what the designed platforms.

ONAP community defines blueprints for various use cases during each release, which can be adopted by the users immediately. Some essential uses cases are –

5G
CCVPN
VoLTE
vCPE

ONAP will bring the next revolution in the field of networking. ONAP stands for an open network automation platform and manages the virtually defined networks. What is the VNF or what’s the big deal about this Virtual Networking?
VNF – Network functions virtualization is a network architecture concept that uses the technologies of IT virtualization to virtualize entire classes of network node functions into building blocks that may connect, or chain together, to create communication services. – Wikipedia.

Why VNF or SDN required?

There are lots of reasons (like vendor issues, complex control panel) to move to virtualization or software-defined architecture.
All the hardware network devices have data planes (describe where data forwarded done through network addressing) and control plane the complex one(its work as a decision-maker and control where should traffic be sent and how quickly).
Control panel is not as simple as network architecture have multiple devices type then have multiple control plane one for each, which results in multiple decision-makers in your n/w which become very complex even at typical network configuration that has a router paired with a firewall device plus a WAN acceleration device.
To solve these issues and reduce the complexity there comes software-defined or virtual networking, that abstracts the data plane and control plane. The NVF converts the single hardware task to the virtual machine or software-defined which does the same work done by hardware devices but in more Agile and adaptive ways. It’s a software application used in Network Functions Virtualization (NFV) that has defined interfaces and provides well-defined networking functions components; the components can be one or more, for example, a security VNF has a function related to NAT and Firewall.
But VNF too has various challenges like Vendor Compatibility and many others, it enables VNF ( Virtual Network Functions), and other network functions and services easily understandable in an automated, policy-driven Real-Time environment. This provides everyone the ability to fully create, design and deploy for Automated Network Services.

How ONAP Works?

ONAP is the result of many software subsystems combined, these subsystems broadly divided into two major architectural framework parts –
Design-time framework – It defines, designs and programs the platform. Again design-time framework consists of the following subsystems –
Service Design and Creation (SDC) – It defines, simulates, and certifies assets and their associated processes and policies.
Policy – It enables the creation and deployment of rules to instantiate conditions, requirements, constraints, attributes, or needs regarding the assets provisioned, maintained, or enforced.
Run-time framework – To execute the programmed logic defined in the design phase. It also consists of following subsystems –