Design of SDN based large multi-tenant data center networks

In this paper, we propose a cost effective hybrid SDN-Ethernet network to realize a large data center network. The network can support hundreds of thousands of physical machines (PM). More than 64K tenants can share in a data center and each tenant can individually own 4K VLANs. In addition, each tenant user fully owns the right to assign IP addresses and VLAN IDs to their Virtual Machines (VMs). The network can support VM live migration and fast failure recovery. To enhance survivability, dual SDN controllers are used to manage the network through in-band control. We apply MPTCP to provide multiple concurrent sub-flows to enhance throughput of TCP connections between VMs. A novel congestion aware routing is proposed for network load balancing. We have conducted experiments and simulations to evaluate the performance of the proposed network. The experimental results show that the system can resume connections between VMs in a short time after VM migrations. As a network failure occurs, the proposed failure recovery scheme can restore network connection fast even if the failure disrupting both control and data channels. Our experimental results also reveal that the proposed light weight congestion aware MPTCP routing outperforms the existing ECMP-based and VLB-based routing in two well-known data center topologies.