Improving inefficient routing and inferior performance

Even if an organization avoids the complexity of multiple static routes or a dynamic routing protocol, its network traffic is extremely inefficient. Consider a branch user’s legacy path to the internet in a legacy WAN architecture. In order to arrive at Google’s search engine website for a simple search, for example, the application flow would need to:

• Cross the branch WAN edge
• Navigate across the MPLS circuit
• Enter the datacenter
• Negotiate its way through a centralized security stack that includes a firewall, intrusion prevention system (IPS), antivirus/anti-malware (AV/AM), data loss prevention (DLP), web filter, and so on
• Travel to the Google website through the datacenter internet edge

The minimal infrastructure required at the branch was traditionally seen as a key benefit of legacy WAN architecture. However, it has largely fallen short of expectations concerning user experience. At a time when consumers have almost universally been using broadband connections at home for more than a decade, legacy WANs do not generally reflect typical broadband speeds. As more and more employees use cloud-based services that require more bandwidth, performance has only declined.

For a diagram of the legacy WAN architecture, see Legacy WAN edge .