Deo Krishneel, Chaudhary Kaylash, Assaf Mansour
School of Information Technology, Engineering, Mathematics and Physics, The University of the South Pacific, Suva, Rewa, Fiji.
PeerJ Comput Sci. 2024 Apr 4;10:e1848. doi: 10.7717/peerj-cs.1848. eCollection 2024.
Quality of Service (QoS) is a mechanism used in computer networks to prioritize, classify, and treat packets differently based on certain criteria. This helps the switching devices to schedule and reorder packets if there is congestion in the network. Edge routers experience high traffic congestion as a result of traffic aggregation from the internal network devices. A router can have multiple QoS classes configured, and each class could experience traffic at various rates. However, when a QoS class is underperforming or needs more bandwidth, some bandwidth can be borrowed or leased out to another QoS class to ensure the link is utilized to maximum capacity and the highest throughput is achieved. This article proposes a bandwidth allocation and distribution algorithm that purely uses the flow statistics from the OpenFlow switches to allocate bandwidth to different QoS classes optimally based on their current requirement. The algorithm does not guarantee in advance that the packet loss will be minimized but does guarantee the initial minimum bandwidth allocation. It adjusts the flows' rates with the aim to increase their current throughput. The algorithm uses the Software Defined Networking (SDN) controller's flow monitoring component to query the flow statistics from the switch to first approximate the traffic flow rate and then calculate the optimal bandwidth values to assign to each QoS class. The proposed algorithms will be applied to certain switches in the path with the assumption that all the switches are OpenFlow compatible. The algorithm's performance was compared with the Adaptive Quality of Service (AQoS) algorithm over various traffic scenarios. The results show that the proposed algorithm achieves an average of 9% performance gain compared to the AQoS algorithm.
服务质量（QoS）是计算机网络中使用的一种机制，用于根据特定标准对数据包进行优先级排序、分类和区别对待。这有助于交换设备在网络出现拥塞时调度和重新排序数据包。由于来自内部网络设备的流量聚合，边缘路由器会经历高流量拥塞。路由器可以配置多个QoS类，每个类可能会以不同速率经历流量。然而，当一个QoS类性能不佳或需要更多带宽时，可以将一些带宽借用或出租给另一个QoS类，以确保链路得到最大程度利用并实现最高吞吐量。本文提出了一种带宽分配和分发算法，该算法纯粹使用来自OpenFlow交换机的流统计信息，根据不同QoS类的当前需求为其最优地分配带宽。该算法不能预先保证将丢包最小化，但能保证初始的最小带宽分配。它调整流的速率，旨在提高其当前吞吐量。该算法使用软件定义网络（SDN）控制器的流监控组件查询交换机的流统计信息，首先估算流量速率，然后计算要分配给每个QoS类的最优带宽值。假设所有交换机都与OpenFlow兼容，所提出的算法将应用于路径中的某些交换机。在各种流量场景下，将该算法的性能与自适应服务质量（AQoS）算法进行了比较。结果表明，与AQoS算法相比，所提出的算法平均实现了9%的性能提升。
