A survey on pushing the port count limits for optical interconnects in data center networks
TL;DR
A novel large port count architecture called Enhanced Port Count (EPC) is proposed that provides port count benefit over existing architecture and analysis of existing architectures in terms of port count and optical components affecting port count.
Abstract
Lots of web based cloud computing applications like high performance computing, content delivery and video streaming, enterprise applications, artificial intelligence and machine learning require large computing power and memory resources which can only be provisioned by a Data Center Network (DCN). A DCN is a collection of a large number of high performance servers and network devices interconnected to achieve a specific task or application. Now a days there is a paradigm shift to replace many electric network devices interconnecting high end servers with a single large port count optical interconnect [1]. The port count and blocking probability of a port of optical interconnects in DCN are important parameters as they affect the overall latency, complexity of routing, and energy consumption in the network; a lower port count of interconnects means a large hop count of the overall network. If hop count is large then at each hop there is store and forwards mechanism which increases latency, complexity of routing and energy consumption all of which are negative markers of performance. Likewise high blocking probability refers to more re-transmissions of packets. There is a growing demand for DCNs, due to compute-hungry demand of modern web-based applications like video streaming, social networking, powerful search engines, and email repositories, just to name a few. Ever since the invention of network packet switching devices, there is a quest for large port count network switches, which actually reduces the number of network switching devices in the network. To enhance the performance of such applications we need optical interconnects which have large port count. The contributions of this paper are threefold i. The design considerations associated with large port count optical interconnects are identified, ii. Analysis of existing architectures in terms of port count and optical components affecting port count, iii. A novel large port count architecture called Enhanced Port Count (EPC) is proposed that provides port count benefit over existing architecture.