利用軟體定義網路基於網路通道多路徑路由應用在內容傳遞網路

Abstract

隨著網路服務的盛行，網際網路的頻寬需求也越來越高。線上服務的效能也直接影響使用者的滿意度，而最主要影響到使用者滿意度的主因則是封包遺失率以及端點至端點的延遲。內容傳遞網路是最普遍被使用的技術，它透過快取以及透過基於網路名稱系統的使用者匹配機制的智能路由來改善使用者的滿意度。然而，由於現在最主要的跨網路路由協定是BGP，它的路由方式容易導致網路中局部連結過載，造成內容傳遞網路在跨區域連線的效能下降。這篇論文中，我們提出一個基於網路通道多路徑的路由系統，此系統透過軟體定義網路的幫助，可以動態的建立網路通道。我們藉由在部分的自治系統中部屬通道系統，使內容傳遞網路能獲得更多的替代路徑來避開壅塞連結。除此之外，我們提出了一個部屬通道系統的演算法，此演算法可以在部屬系統數量的限制下，找出有利的位置來部屬通道系統。最後在我們的研究結果中可以看出我們提出的通道系統有效的降低平均封包遺失率以及端點至端點的延遲，另外，也證實我們提出部屬通道系統的演算法能夠找出適合的地點部屬通道系統。

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.