We are entering one of the most exciting periods in the history of Wide-Area Network (WAN) provision. In a market dominated by Multiprotocol Label Switching (MPLS) systems for very many years, new innovations are poised to shake things up and maybe even challenge the big industry players.

In this article we look at three recent developments in the field: hybrid WANs, Software-Defined Networks (SDNs) and Network Function Virtualisation (NFV). These technologies promise to bring cost efficiencies, faster speeds and improved control of deployment. They will also free enterprises from the need to maintain specialist hardware in their premises.

Like all technological innovation, the new developments will also present challenges. Hybrid WANs rely on internet bandwidth, SDNs could become the target for cyberattacks and NFV can only be implemented effectively if vendors are able to work in close partnerships.

The decline of
traditional WANs

Like many areas of enterprise computing, WANs have been impacted by the arrival of cloud-based services. For many years WAN architecture barely changed: the mature technologies of MPLS and Virtual Private LAN Service (VPLS) delivered the required performance levels unchallenged. The market became relatively static and was dominated by a few big supplier brands.

As businesses have increasingly adopted cloud-based services, however, the landscape is starting to change. By relocating applications to the cloud, tradition designs are being challenged, or are no longer the most optimum solution, making many WAN services appear to be past their sell-by date.

Quicker & Cheaper:
The benefits of hybrid WAN

In response to these changes, companies are increasingly looking to hybrid WANs to bridge the gap between the cloud and traditional networks. This is particularly the case where the WAN is global rather than limited to the UK. Hybrid WAN uses multiple access technologies to get maximum performance for minimum cost.

The advantage of MPLS networks is their reliability for time-critical operations such as transactions or real-time applications. This combines with either local or global internet services and an intelligent or application-aware network overlay to produce a hybrid network.

Businesses value hybrid networks because they reduce costs, particularly for companies operating internationally. An internet-based system is much cheaper than a highly resilient, highly available dual MPLS network, which used to be the standard for international businesses. Under a hybrid model these services are delivered at much lower cost by an internet provider.

Hybrid networks also optimise access to applications, particularly cloud-based applications such as Azure, Office 365, AWS and Google for Business. A hybrid WAN provides a much shorter path to applications by using a local-based internet. On the other hand, with a traditional MPLS network, traffic had to traverse the network and central data centre, often resulting in a poor end-user experience. Enterprises are no longer willing to accept these delays, which can have a significant impact on operations when taken in the whole.

Hybrid WANs deliver great value in terms of cost and speed, but there is a drawback: reliance on the internet to deliver critical applications. Even the very best internet provider cannot guarantee an unvarying level of totally secure, fully reliable service. There will inevitably be fluctuations according to multiple factors.

Traditional MPLS networks provided guaranteed minimum assured bandwidths, ensuring quality of service for critical applications, but the same level of assurance simply does not exist on the internet. While some global service providers offer optimisation, they still cannot reach the levels of reliability and security of a MPLS-based network.

Decoupling intelligence from
the data plane

With traditional networks, every single router needs to have the intelligence to control data flow. With SDN the control of networks is orchestrated through a central platform. It’s a little bit like how the brain controls muscles: each network can operate without needing its own individual source of intelligence.

The key advantage of SDN is that remote locations no longer need to install expensive intelligent appliances. Basic hardware is installed then managed centrally, making deployment and configuration much quicker as you no longer need to set up individual devices. The devices at each location could be commercial off-the-shelf servers or white box appliances that can be plugged in and deployed by anyone, while a skilled engineer implements a virtual appliance and controls policy centrally.

The speed of this solution is especially helpful for sectors such as retail, where deployment is often highly pressurised and time-critical. Instead of engineers configuring legacy MPLS networks one by one, every single router works within a centralised system so they all perform in the same way, at the same time. This promises to deliver cost savings and greater control for enterprises.

Unfortunately, like any software-based system, SDN is vulnerable to bugs, failures and attacks. Under the old way of working a bug or failure would only affect one device, because each point in the network had its own custom intelligence for protection. With SDN a single point of failure could potentially take down an entire network. This would have a major impact on the enterprise using the SDN.

As a centrally-controlled platform with a software overlay, SDNs could also become security targets for hackers seeking to steal commercial information or cause disruption. No major attacks have been reported to date but as time goes by and the technology is adopted more widely, the likelihood of attacks will increase. Security will be one of the main challenges for SDN adoption.

Delivering critical services
off-site with NFV

NFV virtualises functions such as routing, load balancing, web filtering, firewall provision and proxy application. This means services that used to require expensive infrastructure, such as specialist hardware, can be delivered at much lower cost using off-the-shelf hardware.

Although NFV hasn’t been fully productised by all suppliers yet, almost all providers have begun to apply NFV, usually in combination with SDN, within their own internal networks; it is only a matter of time until it makes it onto the marketplace. When it does, enterprises will have the opportunity to shift their key critical services such as firewalling, load balancing and web filtering, onto the cloud along with their internal and enterprise applications. This will enable a further shrinking of their data centres.

The downside of NFV:
Vendors need to work together

One of the major challenges posed by NFV is vendor interoperability. Most enterprises will want to preserve their current vendor model, whether that means best practice dual skimming or using a particular load balancing vendor. In the past, using multiple service vendors generally did not pose any major problems for enterprises.

With NFV, multiple services are virtualised onto a single platform and will need to work together seamlessly. Vendors will have to forge new relationships to make this happen; Cisco is already working with VMware and others are also teaming up.

The challenge for vendors coming out of their silos and learning to work together on service provision may result in more unified solutions, or it could lead to greater conflict. In response, the demand for vendor management services is likely to increase, so that enterprises are spared the extra work involved in co-ordinating vendor collaboration. It’s still early days for NFV, but relationships will be central to its success.

A greater focus on WAN optimisation, rather
than routing

WAN management used to be about monitoring network round trip time and packet transfer: not anymore. As hybrid WAN, NFV and SDN are implemented, management will be much more about monitoring applications and developing deeper insight into application performance.

For example, WAN managers will need to carry out close monitoring at a network level. They will need to scrutinise how applications are routing and take steps to optimise the data flow of applications, whether these are based in an enterprise data centre or in the cloud. Network control will be essential to ensure application performance is optimised.

Exciting times ahead for
the WAN marketplace

Technological advances in hybrid WAN, SDN and NFV are combining to produce genuine change and dynamism in the WAN market. We are about to see a step change in how customers adopt WAN, design their networks and secure support for applications.

New innovation will almost certainly shake up the marketplace and challenge some of the traditional established players. The big names will still play a crucial role in controlling underlying infrastructure such as network design and routing, but there will be smaller, nimbler new providers bringing fresh competition. This is especially true of specialist functions such as NFV and SDN that make use of cheaper internet-based technologies. For a market that has been heavily dominated by MPLS for many years, this is a very exciting period.


Other than matters relating to The Network Collective, this research is based on current public information that we consider reliable. Opinions expressed may change without notice and may differ from views set out in other documents created by The Network Collective. The above information is provided for informational purposes only and without any obligation, whether contractual or otherwise. No warranty or representation is made as to the correctness, completeness and accuracy of the information given or the assessments made.

This research does not constitute a personal recommendation or take into account the particular investment objectives, financial situations, or needs of individual clients. Clients should consider whether any advice or recommendation in this research is suitable for their particular circumstances and, if appropriate, seek professional advice.

No part of this material may be (i) copied, photocopied or duplicated in any form by any means or (ii) redistributed without the prior written consent of The Network Collective Limited © 2018

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