Zeppelin - A Third Generation Data Center Network Virtualization Technology based on SDN and MPLS

Just like computation and storage, networks in data centers require virtualization in order to provide isolation between multiple co-existing tenants. Existing data center network virtualization approaches can be roughly divided into two generations: a first generation approach using simple VLANs and MAC addresses in various ways to achieve isolation and a second generation approach using IP overlay networks. These approaches suffer drawbacks. VLAN and MAC based approaches are difficult to manage and tie VM networking directly into the physical infrastructure, reducing flexibility in VM placement and movement. IP overlay networks typically have an relatively low scalability limit in the number of tenant VMs that can participate in a virtual network and problems are difficult to debug. In addition, none of the approaches meshes easily with existing provider wide area VPN technology, which uses MPLS. In this paper, we propose a third generation approach: multiple layers of tags to achieve isolation and designate routes through the data center network. The tagging protocol can be either carrier Ethernet or MPLS, both of which support multiple layers of tags. We illustrate this approach with a scheme called Zeppelin: packet tagging using MPLS with a centralized SDN control plane implementing Openflow control of the data center switches.