Dynamic Multi-Wavelength Assignment with Link Aggregation on SLAMNet Test System

This paper presents the implementation and performance of the best-effort multi-wavelength assignment with link aggregation on the SLAMNet (Statistical Lambda Multiplexing Network) test system.

Frame-level traffic splitting for link aggregation in data center networks

Ethernet link aggregation, which provides an easy and cost-effective way to increase both bandwidth and link availability between a pair of devices, is well suited for data center networks. However, all the traffic splitting algorithms used in existing Ethernet link aggregation are flow-level which do not work well owing to the traffic characteristics of data centers. Though frame-level traffic splitting can achieve optimal load balance and the maximum benefits from aggregated capacity, it is generally deprecated in most cases because of frame disordering which can disrupt the operation of many Internet protocols, most notably transmission control protocol （TCP）. To address this issue, we first investigate the causes of frame disordering in link aggregation and find that all of them either are no longer true or can be prevented in data centers. Then we present a byte-counter frame-level traffic splitting algorithm which achieves optimal performance while causes no frame disordering. The only requirement is that frames in a flow are the same size which can be easily met in data centers. Simulation results show that the proposed frame-level traffic splitting method could achieve higher throughput and optimal load balance. The average completion time of different sized flows is reduced by 24% on average and by up to 46%.

Improving network service performance and reliability via links trunking technologies

With the increase of high-speed network backbones, the performance of server’s network interface gradually becomes a pivotal factor. This study provides a method called Ethernet Links Trunking (ELT) technology for achieving efficient connec-tivity between backbones and servers, which provides higher bandwidth and availability of server network interface. The overview of the ELT technology and the results of performance experiment are presented in this paper. Findings showed that the network bandwidth can be scaled by multiple ELT technologies so that more reliable network connectivity can be guaranteed. Some crucial techniques such as Adapter Load Balancing (ALB) and Adapter Fault Tolerance (AFT) are presented in this paper. Experimental results showed that parallel channels of Fast Ethernet are both necessary and sufficient for supporting the data rates of multiple concurrent file transfers on file server.

Software Defined Traffic Engineering for Improving Quality of Service

The Software Defined Networking(SDN) paradigm separates the control plane from the packet forwarding plane, and provides applications with a centralized view of the distributed network state. Thanks to the flexibility and efficiency of the traffic flow management, SDN based traffic engineering increases network utilization and improves Quality of Service(QoS). In this paper, an SDN based traffic scheduling algorithm called CATS is proposed to detect and control congestions in real time. In particular, a new concept of aggregated elephant flow is presented. And then a traffic scheduling optimization model is formulated with the goal of minimizing the variance of link utilization and improving QoS. We develop a chaos genetic algorithm to solve this NP-hard problem. At the end of this paper, we use Mininet, Floodlight and video traces to simulate the SDN enabled video networking. We simulate both the case of live video streaming in the wide area backbone network and the case of video file transferring among data centers. Simulation results show that the proposed algorithm CATS effectively eliminates network congestions in subsecond. In consequence, CATS improves the QoS with lower packet loss rate and balanced link utilization.