Read the attached PDF written by Sethuraman Ramanathan to learn how Juniper's Contrail Cloud solution with MPLS-over-UDP overlays is implemented. MPLS-over -UDP Tunnels are used on datacenter environment as overlays. Existing technologies (like MPLS-over-GRE) to encapsulate Multi-Protocol Label Switching(MPLS) over IP are not adequate for efficient load balancing of MPLS application traffic, such as Layer3 Virtual Private Network (L3VPN) traffic across IP networks. This document specifies IP-based encapsulation technology, referred to as MPLS-in-User Datagram Protocol (UDP), which can facilitate the load balancing of MPLS application traffic across IP networks.