Software defined networking and network function virtualisation

05 May 2017

By Graham Lloyd, Head of Fixed Connectivity Product Development, Vodafone

By Graham Lloyd, Head of Fixed Connectivity Product Development, Vodafone

Exploring the opportunities and understanding what needs to be considered

Network technology is evolving and over the next few years we'll see Software Defined Networking (SDN) and Network Function Virtualisation (NFV) become far more commonplace. Although the basic technologies have been around for some time, we are only now seeing maturing, standardised products in the marketplace. 

SDN and NFV are quite different technologies but are related by significant common principles. Today, the Wide Area Network (WAN) is a closed and static environment. While improvements have been made in automating capabilities over the years, general management and delivery is still very much a manual process delivered through individual node Command Line Interfaces. 

The SDN and NFV vision revolutionises these legacy concepts, moving networks to be driven by centralised software control capabilities that can programme the entirety of the network through a set of open APIs. In addition to greater network control, virtualisation is seen as key to driving down the cost of deploying services around the network. 

Looking at each area in a little more detail, NFV is associated with the cloud evolution we are seeing, driven by dynamic requirements for services.  We are moving away from high cost physical appliances towards virtual capabilities which deliver the same service, but instantiated when needed and on a per-customer basis. As NFV is expected to provide a dynamic set of capabilities it also requires a dynamic network to connect them. 

SDN can take many forms, SD-WAN is a specific take on SDN, targeted at the enterprise WAN. Through an abstracted, centralised control plane, WAN services in this instance can be set-up in real time, as needed, between end-points including customer sites, NFV services and third-party locations, such as public clouds. These overlay WAN flows provide connectivity agnostic of the underlying transport, which can be internet, MPLS, mobile, or Ethernet, for example. 

The real game-changer for this evolution in technology is the move to API-driven delivery. This will open up the WAN space to new service innovations and rapid deployment.  We are already beginning to see a step change in WAN services in the marketplace, from what is offered, to how it is procured, to the wider variety of service providers. 

Causing disruption to traditional markets 

SDN and NFV have the ability to be truly disruptive and we are already seeing this materialise. Cloud SD-WAN providers have come into the market and are starting to gain momentum, giving customers alternative options for consideration versus the traditional Telco model. 

The use of internet-only services and hybrid WAN as a potential replacement for the solely MPLS VPN will no doubt lead to reduced like-for-like telco WAN revenues, and customer expectations for price reductions within this model are already becoming clear for many use cases. 

Another challenge we see in the marketplace is from the network vendors themselves, selling directly to large enterprises. The assumption is that if you manage your WAN service at the overlay level, you can drive more cost-effective underlay services if you are prepared to run hybrid and multi-carrier solutions. This could prove appealing to organisations with larger, skilled network teams, but does have associated with it a more complex operating model that businesses will need to take into consideration. 

As already mentioned, one of the big game changers with SDN is it opens up the network to being controlled using open APIs without impacting the physical underlying connectivity. The customer will see rapid development of self-serve capabilities that are not easily available today for both WAN and security services. These will initially be delivered through an evolved portal but eventually, by means of API integration into the SDN and NFV service platforms, delivering even greater dynamic customer controls. Another benefit will be in providing greater real-time visibility of both transport and application performance across the network. The move from static, manually configured networks to fully dynamic service-driven solutions has already begun. 

NFV provides the Telco greater opportunity to offer a wider range of services than possible today. Having the ability to deploy WAN, LAN, and security capabilities, both at the customer site and also at key breakout points of a network, on-demand and in-line with the traffic flow, provides the customer and the service provider with the ability to truly understand the data being transported and manage it better from an optimisation and security perspective. In addition to this innovation opportunity there is a revenue potential not easily accessible currently without consideration of costly, complex technology solutions and managed service arrangements. 

Challenges facing multinationals adopting SDN 

A growing focus we are seeing from customers is around WAN cost reduction. However, savings are not impact-free and this usually materialises around throughput or performance compromises. 

To make the right decisions about where to deploy SDN, organisations need to understand the sites they connect to the network, the application flows and the types of data that traverse these sites. Once these are understood, the business can begin to consider how dynamic its services are, how much critical data it carries between these sites and therefore how much internet transport it is content to consume. 

Another use case already mentioned is based on running SDWAN over a number of underlay providers, whether directly by the customer through a network vendor solution, such as Cisco’s iWAN or with a cloud overlay service. 

From a direct cost perspective, there may be clear benefits of sourcing lowest cost per site/region connectivity, but the impact to the operate model of a complex multi-carrier network and SDWAN overlay should not be considered lightly and the impact of resourcing this approach should be included in the customers’ business case from a cost, risk and skills perspective. 

As mentioned, SDN and NFV will provide the customer a much wider selection of WAN and LAN services through a variety of new delivery and operate models. However, not all of these solutions will fit all customers' IT and business strategies, their traffic requirements, security or risk position. 

Before moving to an SDN solution it is vital that customers understand their short and mid-term objectives, their IT/network and business strategy, and traffic profile to make the right selections based on desired outcomes. SDN will provide a significant cost to the WAN provider to implement, and customers need to identify where they can save with the solution to mitigate the cost of implementation for their network. 

Ultimately, organisations need to decide what their overall end-goal is. Is it cost-saving, is it performance, or is it control and visibility? 

Vodafone Ready Network making a difference 

Vodafone sees SDN and NFV as key technology enablers, as they will not only allow us to considerably enhance our WAN connectivity features and services, it will also provide a platform to offer far greater integration of the complete communication portfolio from unified comms, to private cloud, IoT and of course our mobility footprint. And that greater integration will ultimately allow more efficient and powerful service offerings for our customers. 

To this end, Vodafone has created the Ready Network to offer multiple SDN and NFV capabilities that cater for a wide range of customer preferences. 

Although the fixed market is starting to see cost erosion from increasing hybrid WAN models, Vodafone believes the ability to effectively interwork the overlay service and the underlay bearer together, whether in the form of Internet, MPLS or LTE, provides a far more capable, efficient and compelling platform to offer dynamic services in a more simplistic and secure operational model. As such, Vodafone consider its continued investment in its Mobile and MPLS networks as a real asset moving forward and is looking at underlay SDN with some interest. 

Final thoughts

SDN and NFV offer the telco and the customer a step change in capabilities to support evolving needs within the digital society, from dynamic on-demand service delivery, to the ability to integrate services seamlessly across the network and into the cloud, through to new models of consuming connectivity services. However, to get the most benefit from SDN and NFV, an organisation has to really understand its end state position and what business benefits they are aiming to deliver.