Timeslot Allocation For Intra-rack Optical Time Division Multiplexing System In Data Center

With the digital transformation of modern society and the rapid development of the Internet,emerging technologies such as big data and cloud computing have brought explosive network traffic to the data center while driving data center construction.Data traffic from new services has led to changes in data center network traffic characteristics,bringing new problems and challenges to traditional data center networks.In order to reduce the port congestion caused by the huge"Intra-rack traffic"in the data center and satisfy the QoS requirements of the bandwidth-sensitive services and delay-sensitive services,an intra-rack flow identification based OTS/EPS hybrid network structure in cloud data center is proposed.By collecting and analyzing the intra-rack flow information,elephant flows with a large bandwidth requirement are dynamically scheduled to the optical switch,while the delay-sensitive mice flows are scheduled to the Top-of-Rack switch.It takes full advantage of the electrical packet switching and optical timeslot switching to support new services better.At the same time,the load on the Top-of-Rack switch is greatly reduced,resulting a higher communication quality,a better scalability and less energy consumption.To make the intra-rack hybrid network architecture proposed in the paper practical,the paper designs the Optical-Electrical Hybrid Network Protocol for the centralized controller based on Intel DPDK,optical switch and servers in the rack,including the communication process and message structure.Futhermore,we solve the timeslot allocation problem in the proposed intra-rack Optical Time Division Multiplexing system.The dynamic timeslot allocation algorithm is proposed for this application scenario.It ensures that the elephant flows scheduled to the Optical Timeslot Switching network can transmitted through the optical switch without collision.Besides it optimizes the timeslot allocation speed to effectively support the fine granularity and high throughput f low schedule.In addition,the serial timeslots allocation reduces the optical circuit switching overhead and Clock and Data Recovery time,which improves the network utilization.The simulation results show that compared with the traditional data center intra-rack network,the completion rate of the elephant flow s is promoted by 23%,and the packet delay of the mice flows is reduced by 1 7%.In conclusion,it effectively optimizes the network performance and provides better support for various services in the data center.