The importance of WAN optimisation

by Stuart Hardy, business development director of EOH Global Networks Division UK

Companies are responding to the rise of BYOD (bring your own device) and the need for more flexibility across the board by building WANs that support and enable these requirements.

In some ways the distinction between a LAN and a WAN has come full circle: the speed of Internet connectivity allows many businesses to use cloud to store data, making it easier for staff working from home or in other remote locations to access information. This is effectively a LAN; except that it can now be seen as an extension of the WAN.

WAN efficiency is critical

As WANs become the standard in the business community, it is critical to ensure that these networks are not only set up correctly, but also have the capacity to handle the daily business data traffic.

Businesses can improve end-user experience and satisfaction, flexibly add new offices, and keep pace with customer demands – without costly increases in WAN bandwidth. The key to this is to dramatically improve WAN efficiency.

Many organisations that adopt cloud computing for the numerous business benefits it offers are unaware of the increasing pressure that cloud services place on the WAN. This can even become debilitating. If the network is not stable enough to cope with transferring large volumes of data to the cloud, performance is sacrificed and the benefits of cloud computing fail to materialise.

With businesses embracing virtualisation more widely – for example, by deploying virtual offices – an efficiently performing WAN is a must. And as application delivery becomes more efficient, the burden on the network increases. The ability to add capabilities and business applications is also crucial.

The further business imperative for WAN performance is that with data processing efficiency now a clear differentiator in a competitive marketplace, businesses with efficient, integrated WANs that deliver the data services they need will be the market leaders.

WAN optimisation design and planning

Network convergence and virtualisation are key considerations when designing and optimisation a WAN environment.

When planning the capacity of a WAN optimisation solution it’s best to base calculations on a WAN optimisation appliance’s ability to perform application-layer functions, such as managing user counts and protocol optimisation throughput, rather than on low-level metrics such as TCP counts.

WAN optimisation appliances function as WAN proxies, changing network traffic to accelerate and secure it. These changes can affect TCP counts in unpredictable ways, making TCP counts a poor choice of a metric for capacity planning.

Authentication, byte-caching, compression, protocol optimisation, policy enforcement, and other proxy activities all have the potential to change the number of TCP connections active on a WAN.

Exactly how these activities change TCP counts varies, and it varies so much that TCP counts turn out to be a poor metric for planning WAN optimisation capacity.

A better approach is to determine how many application sessions a WAN needs to support and then to design the WAN solution accordingly.

An effective WAN acceleration solution will make optimal use of lower-level TCP functions while also scaling its higher-level application and session-based functions to meet the growing demands of users.


Stuart Hardy is the business development director of EOH Global Networks Division UK. Stuart has spent 20 years in the South African telecommunications market working at executive level in and with South African telecommunication companies. He is responsible for developing EOH’s global network and for driving global application and global WAN optimisation for EOH out of the United Kingdom. His contact details are or +44 7856 501 896.