軟體定義網路(Software Defined Networking；SDN)發展至今無庸置疑地已是下個世代網路技 術的趨勢，但在現實網路環境中，基於距離、地緣與管理者不同等因素，不可能將所有網路設備 皆交由統一的SDN控制器(controller)管理，因此傳統網路中的自治系統(Autonomous System; AS) 概念將不會被取代， 而一個SDN自治系統如何與外界網路連接則成為新的問題， 本論文將一個 SDN控制器或一個SDN控制器叢集(Cluster)所管理的網路視為一個自治系統，並使用邊界閘道協 議(Border Gateway Protocol; BGP)作為與外界溝通的協議，以達到無論是傳統網路或SDN網路都 可界接之效果。
本論文說明如何在SDN架構下， 布建一個BGP交換中心， 使得此SDN網路擁有與網際網路 (Internet) 中的自治系統溝通的能力； 同時此BGP 交換中心可透過SDN 架構獲得兼容性 (Compatibility) 、操作彈性(Operational Flexibility) 、高可靠性(High Availability) 、可擴展性 (Scalability)以及廠商獨立性(Vendor Independence)。

Software Defined Networking (SDN) is no doubt become a trend of network technology of next generation. Due to distance, geopolitical relations and administrations, it’s impossible to replace the concept of the autonomous system entirely with central SDN controller in the real world environment, So the autonomous systems concept in the traditional network will not be replaced. How An SDN autonomous system can connect to external network will become a new problem. In this paper, we viewed a network controlled by an SDN controller or a cluster of SDN controller as an autonomous system, and use Border Gateway Protocol (BGP) to interact with the rest of the Internet, in order to achieve the effect of both the traditional network and SDN network can be connected.
In this paper, we explain how to build an SDN-based BGP peering point that can make SDN network communicate with autonomous systems on the Internet. SDN’s concept and technology can make BGP peering point have more compatibility, operational flexibility, high availability, scalability, and vendor independence.