Embedding Bandwidth-Guaranteed Network-Based Virtual Ethernet Switches in SDN Networks

摘要

In this paper, we present a design for implementing network-based virtual Ethernet switches (NVESs) on top of a physical substrate consisting of a software-defined networking (SDN) network. An NVES has the same capability as a real Ethernet switch. A user makes a request to provision an NVES by specifying the number of ports and the maximum bandwidth for each port. The substrate network considered in this study is an Open Flow network. The entire network is controlled by an Open Flow controller. The controller is responsible for performing admission control, resource allocation, routing, address learning, and spanning tree protocol. To enhance the resource utilization of the substrate network, multipath routing is applied. Although using multipath routing can significantly improve bandwidth utilization, this approach results in out-of-order packet delivery and introduces additional error-control problems. To resolve these problems, we design a multipath agent to enhance the edge switch capability. The multipath agent is responsible for bandwidth metering, flow splitting, sequence number management, and packet reordering. We evaluated our virtual switches on top of a testbed network that includes not only commercial Open Flow switches but also a GPON-based virtual Open Flow switch. Multiple NVESs share the testbed network. The experimental results show that the user experience when using an NVES is identical to using a real Ethernet switch. In addition to the provision of guaranteed bandwidth for each NVES, traffic isolation among the NVESs is achieved. All NVESs are free of interference from others in the same network.