Exchange 2013 has brought some fundamental changes to the way clients connect to the Client Access services. The most important and noticeable change is the removal of the RPC client access service. Client connectivity is now handled entirely through RPC over HTTPS a feature most should be familiar with from Exchange 2010 known as Outlook Anywhere.
Microsoft made this specific change in order to eliminate the requirement for complex methods of session affinity and improve the end user experience during mailbox failover. When considering the deployment of a load balancer this also allows for a more simplistic layer 4 approach although there is still very much a need for layer 7 load balancing beyond the basic Exchange configuration. Three of these reasons are highlighted and explained below.
A hardware load balancer can offer more than just load balancing for the Exchange 2013 environment. Taking advantage of features such as Kemp’s Edge Security Pack a hardware load balancer can become a multi-purpose appliance. Some of the features that can be offered are pre-authentication and single sign on for the remote Exchange 2013 users providing security to the organization that was once provided by additional products. This allows for coverage of more of the organization’s requirements with a single appliance.