軟體定義網路（ Software-Defined Network，SDN） 與網路功能虛擬化（Network Functions Virtualization，NFV）被視為能帶動下一波網路改革的新式技術，網路服務大廠Google成功地使 用SDN來大幅提升網路使用效率引領了一波SDN的熱潮，同時也使用NFV大幅簡化Data Center的 網路設備，使得Data Center網路的佈建更具彈性。多個國際標準組織與電信運營商也紛紛投入相 關的研究，例如開放式網路基金會（Open Networking Foundation，ONF）、歐洲電信標準化協會 （European Telecommunications Standards Institute，ETSI）、AT&T、NTT Communication、中國 電信、中國移動與國內中華電信等等。本文將從國際標準組織制訂內容來探討SDN與NFV之發展 趨勢，同時並探討SDN應用於電信運營商的挑戰與機會。

Software-Defined Network（SDN）and Network Functions Virtualization（NFV）are regarded as the new technologies to drive the revolution of next–generation network. Recently, network service operator Google successfully adopted SDN to dramatically improve the network utilization efficiency, and also adopted NFV to simply the network equipment and to improve the elasticity of the establishment of Data Center. Several international standard organizations and telecom operators also started to research the SDN and NFV, such as Open Networking Foundation（ONF） , European Telecommunications Standards Institute（ETSI）, AT&T, NTT Communication, China Telecom, China Mobile, and Chinese Telecom. In this article, we will investigate the contents of standards and then conclude the development trends of SDN and NFV. Besides, we will also investigate the challenges and chances of SDN applications in carrier networks.