Futurewei Orange Verizon This document describes the problems that enterprises face today when interconnecting their branch offices with dynamic workloads in third party data centers (a.k.a. Cloud DCs). It examines some of the approaches interconnecting cloud DCs with enterprises' on-premises DCs & branch offices. This document also describes some of the network problems that many enterprises face when they have workloads & applications & data split among different data centers, especially for those enterprises with multiple sites that are already interconnected by VPNs (e.g., MPLS L2VPN/L3VPN). Current operational problems are examined to determine whether there is a need to improve existing protocols or whether a new protocol is necessary to solve them.