By Chet Berry
How will 5G ever become actualized if it requires CSPs to make sweeping changes to their legacy investments and infrastructure? Network Function Virtualization (NFV) and Software Defined Networking (SDN) are envisioned to facilitate the transition of the magnitude required by 5G. If we examine the basic benefit pillars that NFV and SDN claim to deliver, then it becomes clear how this paradigm is essential in the deployment of 5G networks.
So what are NFV and SDN? Simply speaking, Network Function Virtualization is a new networking architecture and framework that takes cloud-based concepts and applies them to telecommunications networks. In NFV, a network is comprised of software-based applications called Virtual Network Functions (VNF) that run in virtual machines or containers on standard Commercial-Off-The-Shelf hardware (e.g., servers, storage and networking devices). As shown below, NFV replaces the traditional purpose-built hardware-based network elements and moves that functionality to the cloud decoupling it from the underlying physical hardware.
NFV is about moving from purpose-built hardware appliances to cloud architecture. Source: Network Functions Virtualization – Introductory White Paper ETSI NFV ISG
Instead of CSPs purchasing purpose-built hardware platforms that perform explicit functions, NFV enables the provider to build a network infrastructure using cloud-based methods (i.e., SaaS, IaaS) to define network element functions. These virtualized applications are then linked together via a concept called “service chaining” to deliver end-to-end services automating a lot of the installation and provisioning functions that previously required manual intervention. You can read more about the benefits in SDx Central’s 2015 Network Functions Virtualization Report.
SDN enhances NFV by providing a controller capability, which consolidates network control (brains) of the packet forwarding function (muscle) and provides a centralized view of the distributed network for more efficient orchestration and automation of network services. Jointly SDN and NFV provide a framework that allows for network self-diagnostic and lifecycle management with minimal manual intervention. SDN and NFV are complementary approaches that offer a new way to design, deploy and manage telecom networks and its services. Networks based on NFV/SDN are inherently more flexible, programmable, scalable, and more efficient.
The ETSI NFV Industry specifications Group (ISG) has a working group (WG) that is explicitly commissioned to define an NFV architectural framework for functional virtualization of network functions; management and orchestration of network functions and services; and Business / Operations support interfaces for lifecycle supervision (i.e., FCAPS) . The diagram below shows a high-level component view of the major functional blocks of the architecture, the reference points and connections.
ETSI NFV architecture consisting of virtualized network functions (VNFs) running on virtual compute, storage and networking resources controlled by a management and service orchestration set of functions.
The goal of ETSI NFV WG is to define architecture, open APIs and reference points, leveraging open source proof of concept (PoC) projects and communities to drive open standards. These open standards are intended to enable 3rd party vendors to develop framework components that can collaborate with various vendor components so that CSPs are not restricted in selecting functional and management components. NFV will allow network operators to more efficiently use their resources based on the dynamic needs of their services. CSPs are able to achieve greater network configuration agility with respect to capacity scaling as well as integrating new functional elements to deliver new services.
The Open Network Forum (ONF) has defined requirements for SDN. It is actively collaborating with ETSI NFV WG and other organizations to ensure that specifications and requirements are aligned and with minimum overlap. ONF is defining its requirements for the SDN controllers using the OpenFlow protocol between network elements and SDN controller (i.e., southbound interface).
As the 5G frontier continues refinement, definition and specification over the next 5 to 10 years, it is apparent that the mobile network landscape will mandate a total facelift to address the demands of the new services, capacity loads, bandwidth targets, QoE (infinite Internet, RTT latency response), QoS (ubiquitous access, robustness, reliability) and scalability dynamics that are the underlying tracks leading to 5G. 5G ‘s characteristics include:
- More connected devise (1000 x)
- Higher subscriber densities (up to 12,000 devices per km^2)
- Low latency (<1ms RTT)
- Higher data rates (>10,000 Mbps)
This means 5G will require an infrastructure that is highly flexible, dense, fast, accessible, resource efficient and can scale as needed to meet the dynamic needs of the underlying network services. In order to get to that leading edge, it is with no uncertainty that this transition will not happen without the networking architecture of NFV and SDN. 5G will introduce a new lifestyle to the masses, and it will ride on the NFV-SDN train that is currently taking the CSP eco-system by storm. How are you planning for 5G? Let us know by tweeting us at @Dialogic.