A Tunnel-Based Multi-Path Routing for Content Delivery Networks Using Software-Defined Networking

With the prevalence of online application, the bandwidth requirement for the Internet has grown more and more huge.Performance of online applications directly impacts user satisfaction. the major factors which impact the user-perceived performance of the application are packet loss rate and end-to-end delay. Content Delivery Networks (CDNs) are typically used to improve user-perceived application performance through a combination of caching and intelligent routing via DNS-based user mapping mechanism. However, due to Border Gateway Protocol (BGP) is the current dominator inter-network routing protocol, its routing nature known to overload popular links on the Internet causes a performance degradation on middle mile for CDNs. In this paper, we describe a tunnel-based multi-path routing system for dynamically constructing tunnel paths with the help of Software Defined Networking (SDN). By deployment tunnel systems in a part of autonomous systems, CDNs get more alternative paths to avoid congestion links. Moreover, we propose a tunnel system deployment algorithm to find out beneficial positions to deploy tunnel systems with quantity limitation. As last, our simulation result shows tunnel systems can effectively reduce average packet loss rate and end-to-end delay. Moreover, it proves our proposed algorithm is able to successfully choose profitable positions to make tunnel system deployment.