Windows Server 2016 includes Software Load Balancing for Software Defined Networking, and there's a new topic, Software Load Balancing (SLB) for SDN, that will give you an overview of this new technology.
SLB is great for Cloud Service Providers (CSPs) and Enterprises that deploy SDN with Network Controller, RAS Gateway in multitenant mode, and other SDN technologies.
SLB works by mapping public-facing virtual IP addresses (VIPs) to datacenter internal dynamic IP addresses (DIPs) that are part of a cloud service set of resources in the datacenter.
Included with SLB is a software multiplexer (MUX) that runs on one or more Virtual Machines (VMs), and the MUX translates the VIPs to DIPs, then sends incoming tenant network traffic to the correct DIP pool of tenant resources.
When tenant VMs respond and send outbound network traffic back to the Internet or remote tenant locations, because the Network Address Translation (NAT) is performed by the Hyper-V host, the traffic bypasses the MUX and goes directly to the edge router from the Hyper-V host. This MUX bypass process is called Direct Server Return (DSR).
For more information, see Software Load Balancing (SLB) for SDN.