近年來軟體定義網路這一概念出現，並且為網路界帶來一波革命性的進展。藉由軟體定義網路所帶來的增加網路彈性和可程式化控制，研究人員對如何利用軟體定義網路來開發創新技術以解決網路的問題越來越感興趣。然而，目前軟體定義網路大多被作為一個單獨的網路系統來部署以及操作，因此如何將軟體定義網路的技術加入廣域網路的通訊，聯合多個領域來提供研究人員一個混和式多領域軟體定義廣域網路的測試平台，成為了一項熱門的研究議題。因此，在本篇論文裡，我們致力於設計並實作出一個在軟體定義網路下的路由交換機制來實現軟體定義網路的跨領域通訊。考量到在傳統網路下廣泛部署來實現跨領域通訊的邊界閘道協議，在這篇論文裡我們將設計一個具邊界閘道協議溝通功能的應用程式於軟體定義網路中，該應用程式負責與外部系統建立對等連接並交換路由訊息。我們也實行實驗來驗證我們提出的設計的可行性，並做了一個初步的測試來展示系統的效能。

Recently Software-Defined Networking (SDN) has already emerged as a revolution to the network field. With the flexibility and programmability it provides, researchers are getting interested in developing innovation to solve significant network problems. However, currently SDN networks are usually deployed and operated as a single domain system. To utilize SDN technology in Wide-Area Network (WAN) communication, federating single domains into a hybrid multi-domain SDN testbed has become a hot research topic. As a result, we are devoted to provide a routing exchange mechanism in SDN to enable SDN’s inter-domain communication. Considering the wide-deployed Border-Gateway Protocol (BGP) for inter-domain communication in legacy environment, in this paper, we design and implement a BGP speaker application in the SDN network to peer with the external domains and achieve routing information exchange. We also execute experiments to confirm our system’s feasibility, and give a preliminary demonstration to its performance.

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