+3). IPv4/IPv6 + NAT4/NAT6 encap types:
+This type provides kube-proxy data plane on user space,
+which is used to replace linux kernel's kube-proxy based on iptables.
+
+Currently, load balancer plugin supports three service types:
+a) Cluster IP plus Port: support any protocols, including TCP, UDP.
+b) Node IP plus Node Port: currently only support UDP.
+c) External Load Balancer.
+
+For Cluster IP plus Port case:
+kube-proxy is configured with a set of Virtual IPs (VIP, which can be
+prefixes), and for each VIP, with a set of AS addresses (ASs).
+
+For a specific session received for a given VIP (or VIP prefix),
+first packet selects a AS according to internal load balancing algorithm,
+then does DNAT operation and sent to chosen AS.
+At the same time, will create a session entry to store AS chosen result.
+Following packets for that session will look up session table first,
+which ensures that a given session will always be routed to the same AS.
+
+For returned packet from AS, it will do SNAT operation and sent out.
+
+Please refer to below for details:
+https://schd.ws/hosted_files/ossna2017/1e/VPP_K8S_GTPU_OSSNA.pdf
+
+
+## Performance