It seems that we in the networking industry have been talking about evolving the WAN for well over 20 years now. The traditional “hub and spoke” WAN that we’ve all grown accustomed to was ideally suited for client/server computing, where users were in branches and applications were located in the data center.
Over the years there have been small, incremental changes to the WAN that have improved the performance and security of the network. MPLS is now the de facto standard instead of frame-relay and WAN optimization has become a core service for many organizations. These changes did indeed improve the WAN marginally, but it’s time to overhaul and re-architect the WAN.
Most companies have survived with a legacy WAN for years, so why do I now think WAN evolution is a business imperative? The primary reason is that compute is shifting from client/server and the internet to cloud and mobile. Cloud and mobile computing create entirely different traffic patterns than legacy computing models. Also, business agility is a top priority for company leaders, and that drives the need for IT agility and, more specifically, network agility. As a result, today’s networks are highly inflexible.