Open-CCN: 以OpenFlow建置內容為主的網路平台

Abstract

在過去人們使用Internet主要是要獲得各類的資訊，像是多媒體如影片、音樂和資料等，而在現今大量的媒體以及Internet的用戶下，傳統的網路架構可能會遭遇各式問題像是手機與平板電腦都具上網能力將使得IP地址不足、Youtube等多媒體伺服器頻寬耗損嚴重以及數以百計的連線造成伺服器龐大的處理負擔等。因此，內容為中心的網路(Content-centric Network, CCN )提出了一個新的概念，它以內容(content)名稱取代IP位址，並且在每個路由器上加入快取記憶體來暫存資料，這使得客戶端不需要知道資料伺服器的位置，只要知道content為何。在CCN中，客戶端在提出具有content名稱的請求後，可在沿途就近的路由器就獲得資料，而不需走到要到伺服器來拿取，如此能減少多餘的頻寬耗損並減少伺服器負擔。然而如何有效實現CCN於現有的網路中將成為一個重要議題，本篇論文提出一個基於軟體自定網路(Software Defined Networks, SDN)架構所實現的CCN網路稱為Open-CCN，當中為了和現有IP網路相容，並允許目前IP裝置能無縫地存取Open-CCN，我們導入了隧道技術(tunnel)與IP-Name轉換的代理伺服器機制，此外也提出了一個多來源的傳輸協定來增加資料傳輸時的效能。最後我們使用現有商業化的網路設備建立一個小型的Open-CCN網路，除展示其運作外也針對各個網路元件的設計進行分析並且評估其效能。

People have been used to obtain many kind of information from Internet, such like video, music, data. However, the explosion of Internet user and multimedia data caused many problems in current network architecture, such as insufficiency IP addresses for the increasing number of mobile devices, high bandwidth consumption for multimedia services like Youtube, heavy server loading for hundred thousand of multimedia connections, etc. For these reasons, the Content-Centric Networking (CCN) is proposed to provide a new networking paradigm. It uses content name to replace the IP address and allows each CCN router to cache content. The user no longer cares where but what the content is. In CCN, a request with the content name will hit the cache as it passes through the router on the way to a data server. As a result, data can be coming from a nearby router instead of the server. Therefore, both bandwidth consumption and server loading can be decreased. However, how to realize CCN in current network architecture becomes an important issue. We propose to use Software-defined networking (SDN) to realize content-centric network named Open-CCN. In order to coexist with IP network and allow current IP devices to access Open-CCN seamlessly, an IP-Name translation proxy server and tunneling are introduced. In addition, we proposed a multiple sources transport protocol in order to improve data transmission rate. Finally, we use the commercial network appliances to build a small network to demonstrate the function and the performance of each network component in our Open-CCN network.