A Traffic Meter Based on a Multicolor Marker for Bandwidth Guarantee and Priority Differentiation in SDN Virtual Networks

摘要

Network virtualization is a technology that enables multiple tenants to share a common physical network. A virtual network (VN) needs to have dedicated bandwidth and a priority differentiation capability to provide quality of service (QoS) for its serving flows. In this paper, we propose a traffic meter based on a multicolor marker (MCM) to fulfill both inter-VN and intra-VN QoS requirements. In our system, a VN's guaranteed bandwidth is dedicated to the VN, and the bandwidth is not influenced by the traffic generated from other VNs in the same physical network. In addition, the high-priority traffic of a VN can always achieve its needed bandwidth unless the total amount of high-priority traffic exceeds the VN's guaranteed bandwidth. This feature enables a network to provide independent QoS differentiation for each VN. Our MCM meters can be applied in two operation modes. In the remaining bandwidth nonsharing (RBNS) mode, the guaranteed bandwidth is treated as an upper bound for each VN, even if the network has unused capacity remaining. However, in the remaining bandwidth sharing (RBS) mode, the unused network capacity is shared among VNs so that a VN can use more than its guaranteed bandwidth. To validate our design, we implemented our MCM meter in P4 programmable switches. The experimental results on a testbed reveal that our design can accurately achieve bandwidth isolation and QoS differentiation for network virtualization in P4-based software-defined networking (SDN).