Network Function Virtualization: Beyond the Hype

October, 2019 · Reading time: 8 minutes

By late 2019, Network Function Virtualization (NFV) has matured from an experimental concept into an essential component of modern service provider and enterprise architectures. The initial enthusiasm gave way to cautious evaluation, then to more deliberate adoption. This blog dives into where NFV stands now, what problems it solves today, and what it means for the future of network infrastructure.

NFV: A Quick Recap

NFV decouples network functions—like firewalls, load balancers, or WAN optimization—from proprietary hardware, enabling them to run as virtual machines or containers on commodity x86 servers. The goal is to improve agility, reduce capex/opex, and align network infrastructure with cloud-native principles.

Real-World Use Cases

Today, service providers use NFV to deploy virtual customer-premises equipment (vCPE), virtual evolved packet cores (vEPC), and virtual firewalls. Enterprises rely on NFV for branch connectivity, integrated service chaining, and elasticity in multi-site WANs.

Operational Benefits

• Rapid provisioning and scaling
• Centralized management via orchestration platforms like ETSI MANO
• Improved service agility and reduced time-to-market
• Hardware lifecycle decoupled from software innovation

Challenges and Constraints

Despite its potential, NFV adoption has seen delays. Performance concerns (especially for stateful functions), orchestration complexity, and interoperability gaps continue to plague large-scale NFV rollouts. Some organizations find that traditional appliances still outperform VNF equivalents for packet-intensive workloads.

NFV and SDN: Friends or Foes?

NFV and Software Defined Networking (SDN) are often confused or conflated. While SDN separates control and data planes to centralize policy, NFV focuses on virtualization of specific network services. Together, they offer powerful synergies, especially when orchestrated using a unified platform such as ONAP or OpenStack Tacker.

Deployment Models

• Single-VNF on Single VM: Easy to deploy but less resource efficient
• Multi-VNF Service Chains: Enables complex policies and services
• Containerized VNFs (CNFs): A rising trend, especially in Kubernetes environments

Vendor Landscape

Leading vendors have adapted their product lines to support NFV. Cisco, Juniper, Nokia, and VMware all offer robust VNF portfolios and orchestration tools. Open-source initiatives like OPNFV and Open Baton have also driven innovation, helping standardize interfaces and improve VNF validation.

NFV in Hybrid Environments

Many enterprises mix physical and virtual appliances, blending traditional routers with NFV-based firewalls and WAN optimizers. Hybrid models allow for incremental transitions, enabling gradual migration without massive forklift upgrades.

Future Outlook

Looking ahead, NFV continues to evolve. The rise of 5G, edge computing, and containerization will further shape the role of virtual network functions. As Kubernetes-native networking matures, we expect many legacy VNFs to be refactored into CNFs, optimized for microservices and horizontal scaling.

Eduardo Wnorowski is a network infrastructure consultant and Director.
With over 24 years of experience in IT and consulting, he helps organizations maintain stable and secure environments through proactive auditing, optimization, and strategic guidance.
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