Towards full virtualization of SDN infrastructure

With the emerging multi-tenant virtual networks in the cloud data center and the network slicing in wide-area network, full virtualization of the hardware network infrastructure is required. In this work, we propose SVirt, a full virtualization architecture of the software defined networking (SDN) infrastructure, which can flexibly support multiple virtual networks (tenants) to simultaneously run SDN on top of the same physical network. In order to simultaneously run multiple virtual SDN switches with different processing logics on the same physical switch, we redesign the physical switch's processing pipeline with a “late-binding key extractor (LBX)”. In the control plane, SVirt enables “many-to-one” and “one-to-many” mapping when allocating the physical resource for a virtual network, which embraces arbitrary topology and ternary content-addressable memory (TCAM) resource demanded by a virtual network. In the data plane, SVirt explicitly carries the forwarding context information in the packets, overcoming the “context-loss problem” in a virtual network. We develop a NetFPGA prototype of SVirt switch. Event-driven simulations and prototype-based experiments demonstrate that, compared with traditional approaches, SVirt significantly enhances the cloud's capability to accept various virtual SDN requests with resource utilization ratio of more than 90% and improves the network's throughput by around 236%. Besides, SVirt can hold more flows than traditional approaches, thus reducing two-order more table misses.