摘要：Better cost effectiveness of Software-Defined Network(SDN) is motivating enterprises to adopt it in Wide Area Network(WAN). The idea is then called Software-Defined Wide Area Network(SD-WAN). In this paper, first we review the architecture of SDN, which provide theoretical support for SD-WAN. Then we analyze three typical SD-WAN realizations, which are Google's B4, Microsoft's SWAN and Software-Defined Internet exchange Point respectively. Finally, we make a conclusion and discuss future works.
