How do you develop and test virtual network functions and applications using agile and DevOps methodologies?

Developing and testing Virtual Network Functions (VNFs) and applications using Agile and DevOps focuses on iterative development, security, and scalability. Key strategies include defining clear requirements, Agile sprints, and automating testing and deployment through CI/CD pipelines. Performance, security, and stress testing ensure VNFs meet quality standards. Cross-functional collaboration between developers, network engineers, and operations is vital, with regular feedback loops. Using NFV orchestration, containerization, and performance monitoring enhances scalability and efficiency. Continuous telemetry, service chaining, and documentation ensure VNFs are resilient, secure, and ready for rapid deployment and improvement.

Incorporating Agile and DevOps methodologies for developing and testing Virtual Network Functions (VNFs) and applications is about embracing continuous integration, continuous delivery, and rapid iteration. These methodologies focus on collaboration, feedback, and small, frequent updates. In my experience, implementing Agile and DevOps for VNF development requires a cultural shift where the development, operations, and testing teams work closely together. For a telecom project, we adopted Scrum, holding regular sprints and reviews, which significantly improved our response to changing requirements and sped up the deployment cycle.

At basic level, traditional VNFs comes with limitations such as VNFs consumes huge amount of hardware to be able to highly available VNFs are developed, configured and tested to run for specified NFV hardware infrastructure Need manual installation, configuration, and deployment on NFVi API not provided for VNF to enable automated scaling, configuration to serve the sudden spike in demand for utilization Not supporting multi-tenancy. VNFs cannot be easily shared in infrastructure for reuse.

These approaches emphasize collaboration and communication between team members, allowing for quicker problem-solving and decision-making. Additionally, Agile and DevOps encourage regular testing and deployment of software updates, enabling organizations to respond rapidly to changing market demands. By adopting these methodologies, businesses can achieve greater efficiency, productivity, and customer satisfaction.

Selecting the right development tools and frameworks is crucial for efficiency and effectiveness. This includes using virtualization tools, cloud-based development environments, and specific frameworks designed for network functions, like Tacker or OSM. I've utilized containerization tools like Docker and Kubernetes for VNF development, which allowed for easier scaling and management. Integrated development environments (IDEs) and continuous integration tools like Jenkins were also part of the stack, streamlining the development and deployment process.

Testing is important for all software, especially critical parts like network security. Automated testing which deploys virtual environments and runs sanity/regression tests in order to maintain invariants can prevent catastrophic failures in the long term. These can be deployed using regular DevOps tools such as Ansible and Jenkins which manage all orchestration from end-to-end. Nix, Guix, or even SystemD units can be treated as code in order to set the tests up.

The most important best practice when testing new VNF workloads is to never test them in production. While this may sound obvious, there are still many organisations out there that make updates and config changes directly in production. The big difference between manual and automated change processes is that when the changes are being automated, they propagate very fast. This applies to both configuration errors and buggy updates, which makes testing a critical part of continuous integration. So before you operationalise automation, first make sure you have a proper sandbox running. And then remember to test all your automated changes in that sandbox before going live.

Agile emphasizes collaboration between developers and product management — DevOps includes the operations team Agile centers the flow of software from ideation to code completion — DevOps extends the focus to delivery and maintenance Agile emphasizes iterative development and small batches — DevOps focuses more on test and delivery automation Agile adds structure to planned work for developers — DevOps incorporates unplanned work common to operations teams

Agile is an iterative approach to project management and software development that focuses on collaboration, customer feedback, and rapid releases. It arose in the early 2000s from the software development industry, helping development teams react and adapt to changing market conditions and customer demands.

DevOps promotes a fully automated continuous integration and deployment pipeline to enable frequent releases, while Agile provides the ability to rapidly adapt to the changing requirements and better collaboration between different smaller teams.

Building cloud-native VNFs overcomes above discussed limitations of traditional VNFs and gives below benefits Cloud-native VNFs have APIs which enables automated installation and configuration automated scaling when dynamic requirement from network self-healing or fault-tolerant automated monitoring and analysis of VNFs for errors, capacity management, and performance automated upgrading and updating VNFs for applying new releases and patches Standard and simplified management enable less power consumption. Reduction of un-necessary allocated resources. Reusability and sharing of processes within VNFs can be achieved. VNFs can be easily shared within NFV environment.