Support for multi-tenancy has become a core requirement of data centers (DCs), especially in the context of data centers supporting virtualized hosts known as virtual machines (VMs). Three key requirements needed to support multi-tenancy are: o Traffic isolation, so that a tenant's traffic is not visible to any other tenant, and o Address independence, so that one tenant's addressing scheme does not collide with other tenant's addressing schemes or with addresses used within the data center itself. o Support the placement and migration of VMs anywhere within the data center, without being limited by DC network constraints such as the IP subnet boundaries of the underlying DC network. An NVO3 solution (known here as a Data Center Virtual Private Network (DCVPN)) is a VPN that is viable across a scaling range of a few thousand VMs to several million VMs running on greater than one hundred thousand physical servers. It thus has good scaling properties from relatively small networks to networks with several million DCVPN endpoints and hundreds of thousands of DCVPNs within a single administrative domain. A DCVPN also supports VM migration between physical servers in a sub-second timeframe. Note that although this charter uses the term VM throughout, NVO3 must also support connectivity to traditional hosts e.g. hosts that do not have hypervisors. NVO3 will consider approaches to multi-tenancy that reside at the network layer rather than using traditional isolation mechanisms that rely on the underlying layer 2 technology (e.g., VLANs). The NVO3 WG will determine which types of connectivity services are needed by typical DC deployments (for example, IP and/or Ethernet). NVO3 will document the problem statement, the applicability, and an architectural framework for DCVPNs within a data center environment. Within this framework, functional blocks will be defined to allow the dynamic attachment / detachment of VMs to their DCVPN, and the interconnection of elements of the DCVPNs over the underlying physical network. This will support the delivery of packets to the destination VM within the scaling and migration limits described above. Based on this framework, the NVO3 WG will develop requirements for both control plane protocol(s) and data plane encapsulation format(s), and perform a gap analysis of existing candidate mechanisms. In addition to functional and architectural requirements, the NVO3 WG will develop management, operational, maintenance, troubleshooting, security and OAM protocol requirements. The NVO3 WG will investigate the interconnection of the DCVPNs and their tenants with non-NVO3 IP network(s) to determine if any specific work is needed. The NVO3 WG will write the following informational RFCs, which must have completed Working Group Last Call before rechartering can be considered: Problem Statement Framework document Control plane requirements document Data plane requirements document Operational Requirements Gap Analysis Driven by the requirements and consistent with the gap analysis, the NVO3 WG may request being rechartered to document solutions consisting of one or more data plane encapsulations and control plane protocols as applicable. Any documented solutions will use existing IETF protocols if suitable. Otherwise, the NVO3 WG may propose the development of new IETF protocols, or the writing of an applicability statement for non-IETF protocols. If the WG anticipates the adoption of the technologies of another SDO, such as the IEEE, as part of the solution, it will liaise with that SDO to ensure the compatibility of the approach.