Virtual Network Function (VNF) onboarding is simply more than VNF Descriptor (VNFD) configurations

July 20th, 2018 by · Leave a Comment

This Industry Viewpoint was authored by Prodapt

More and more digital service providers (DSPs) are adopting Virtual Network Function (VNF) to reap key benefits of virtualization such as accelerated service realization, reduced time-to-market, better scalability, and cost-effective & centralized network monitoring.

There is a popular misconception that VNF onboarding involves just the following three steps.

  • Getting the VNF image from the vendor
  • Loading it on to management and orchestration (MANO) platform
  • Making the necessary changes in the configuration files and service package templates

However, VNF onboarding is much more challenging than that and many DSPs face major roadblocks during the onboarding process. Huge customization and integration efforts are involved in the service providers’ existing setup as well as in VNF image to make virtual function operate within a broader ecosystem (across legacy O/BSS & product catalog systems) and manage services over its lifecycle. Other challenges include VNF Service chaining and effective program governance. It is recommended to look beyond the configuration files and implement a robust onboarding process in a holistic way right from VNF image validation to VNF ready for service and continuous innovation.

The recommended process of VNF onboarding and key recommendations for faster service realization

1. Product definition & catalog onboarding

Once VNF image is received from the vendor, create product catalog populated for each VNF descriptors. Then create product definition in the catalog for each VNF deployment flavor (example: vFW_LARGE, vFW_MEDIUM, vFW_SMALL).

Key considerations for product definition & catalog onboarding:

It is recommended to mirror the VNF product/service configurations for seamless integration across O/BSS systems such as:

  1. Product catalog/inventory
  2. Self-care
  3. Order management
  4. Assurance
  5. Billing system

Build the revenue generation chain for VNFaaS in Virtual Infrastructure Manager to support models such as:

  1. Pay-as-you-grow
  2. Pay-as-you-need
  3. Dynamic/Flexible billing capability (based on services consumed by VM/tenant)

2. VNFD customization and parameterization

Create tailor-made and parameterized VNFD to accommodate run-time inputs in order in-take process (e.g. customer order form) and integrate the VNF workflow with O/BSS systems for order delivery.

Key considerations for VNFD customization and parameterization

  • Service configuration elements should be passed as parameters from customer service order form to the actual service template during service order activation
  • VNF package incorporation into service design/blueprint along with service instantiation
  • Monitor the VNF with the help of VNFM/EMS (Element Management System) and readjust resources as per the requirements of VNFaaS

– ensure service runs at desired speed/throughput

– ensure virtualization advantages (auto-scaling, flexibility, & agility)

3. Map product catalog variants to virtual infrastructure and VNF service chaining

Analyze and map the product variants to the correct deployment flavors. Effective mapping enables in providing options to customers to choose the right VNF flavor. The VNF package to be onboarded must include all necessary metadata and binary executables to enable deployment.

Create VNFD forwarding graphs to realize VNF onboarding and Incorporate VNF into service design templates to achieve VNFaaS (Virtual Network Function as a Service). E.g. VNFaaS and vCPE services

Key considerations for product catalog variants mapping to Virtual Infrastructure and VNF Service Chaining

Assess the VNF package and ensure the interoperability with orchestration platforms by performing basic package validation. Below are the key aspects to look for in VNF metamodel.

  • Technical Details – Templates (HEAT, TOSCA)
  • Business Semantic – Functional and non-functional aspects
  • Behaviours – Behaviours of its exposed function (policies, management APIs etc.)

4. CI/CD/CT pipeline integration

Onboard VNF service management onto a CI/CD/CT pipeline and verify that existing services are not impacted due to service chaining with the existing ones (regression testing of existing services). E.g. Automated testing of changes.

Key considerations for CI/CD/CT pipeline integration

  • Setup a VNF test/QA team to certify VNFs for integration with customer environments as “ready for service”
  • Integrate CI/CD/CT pipeline with the dynamic push of VNFD configuration to achieve zero-touch provisioning
  • Validate interoperability with multiple orchestration scenarios so that ingestion and administration problems in the customers’ operational deployments are minimized

By following the above holistic approach in VNF onboarding process, DSPs can achieve following benefits:

  • Faster VNF and service onboarding
  • Improved service resilience and high availability (level of 5 9s’)
  • Automated VNF instantiation through CI/CD/CT pipeline
  • Improved customer experience with near real-time order to activate process


Rajan RN, Head, SDN/NFV Labs, O/BSS Practices & AVP, Prodapt

Vishwa Nigam, Manager, Strategic Insights, Prodapt

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Categories: Industry Viewpoint · NFV

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