Network Function Virtualization (NFV) based Transformation of Telecommunication Operators
By Amila Saputhanthri
Introduction
The mobile operators worldwide have been focusing on a Network Function Virtualization (NFV) driven technology transformation since the publication of NFV standards by The European Telecommunications Standards Institute (ETSI) in 2012. With the standardization of fifth generation (5G) cellular technologies, mobile operators are now rapidly adopting NFV. This NFV driven technology transformation will allow mobile operators to decouple software and hardware and efficiently handle dynamic traffic via scaling functionality. Cost reduction, operational efficiency and new revenue streams are the major expectations of mobile operators from NFV. The critical telecommunication Network Functions (NFs) such as Evolved Packet Core (EPC), Mobility Management Entity (MME) and IP-based Multimedia Services (IMS) have already been designed as Virtual Network Functions (VNFs) and tested in Network Function Virtualization Infrastructure (NFVI) by respective vendors.
NFV architecture
The Figure 1 below shows the ETSI NFV architecture referred by the NFV community as the base for developing visualization platforms for mobile operators. The ETSI NFV architecture comprises of a module based architecture where each module is responsible for a specific task to realize virtualization.
Fig. 1. ETSI NFV architecture [https://www.etsi.org/technologies/689-network-functions-virtualisation]
- Virtualization Layer
- Virtualized Infrastructure Manager (VIM)
- Virtualized Network Function Manager (VNFM)
- NFV Orchestrator(NFVO)
This virtualization layer is responsible to create virtual compute, network and storage on top of physical hardware. KVM is mostly used by the NFV community.
Controlling and management functionalities of compute, storage and network resources are the responsibilities of VIM. This includes functionalities such as creating a VM, assigning resources to a VM, etc. OpenStack is the most widely adapted software platform as the VIM.
VNF management functions are done by VNFM. This includes instantiate, scale and terminate VNFs, VNF healing, etc. Critical telco application providers have developed their own VNFMs. Generic VNFMs are also available.
Virtual compute, network and storage resource management of VNF is done by NFVO. This orchestrator should have a bird’s eye view of the NFV and the deployed VNFs. In-order to mitigate resource conflicts, it’s not recommended to bypass the orchestrator, if available.
The NFs need to be developed as VNFs to deploy them in a NFV architecture. A VNF can be deployed in a single VM or over multiple VMs. In the second scenario, a single component of the VNF will be deployed in each VM. A VNFM is required to perform the VNF life cycle management functionalities which includes instantiation, scaling, termination, etc. A fully fledged VNF which follows ETSI standard should have a VNFM to achieve virtualization benefits of NFV.
Conclusion
Mobile operators have been relying on vendor specific network nodes which consist of hardware and software as one package for the last few decades. This approach has created a vendor lock for the network operators as the whole process of physical server installation to software installation is very time consuming. But, the latest technologies such as 5G requires the solutions to be introduced quickly and the support for NFV is inevitable. With the introduction of NFV, operators will have the flexibility of obtaining hardware resources from any vendor and deploy any network node as a software element called VNF. This has allowed the mobile operators to decouple software and hardware and efficiently handle dynamic traffic via scaling functionality.
Eng. Amila Saputhanthri
Eng. Amila Saputhanthri has earned his first degree in Electronics and Telecommunication Engineering from the University of Moratuwa and then, a postgraduate qualification in telecommunication. He is currently working as a Lead Engineer at Dialog Axiata PLC
