While some organizations continue to make use of WAN services such as Frame Relay and ATM, the use of those services is quickly diminishing. As a result, we are rapidly approaching a time when IT organizations will have only two WAN services to choose from: MPLS and the Internet. Given that trend, a key question facing network organizations is how to best design a branch office WAN using just those two services.
The traditional approach has been to have T-1-based access to a service provider’s MPLS network at each branch office and higher speed links, possibly one or more T-3 links and/or high speed Internet links, at each data center. In many cases a key characteristic of the traditional branch office WAN has been multiple hardware-based appliances in each branch office to perform a wide range of functionality, including security and optimization.
One downside of this approach is that the provisioning and configuring of these appliances is complex and time consuming. Another common characteristic of the traditional branch office WAN is backhauling Internet traffic to a data center before handing it off to the Internet. Since the Internet traffic transits the MPLS link, this adds cost and delay.