A software-defined wide area network (SD-WAN) is a wide area network that uses software-defined network technology, such as communicating over the Internet using overlay（1）which are encrypted when destined for internal organization locations. SD-WAN simplifies the management and operation of a VAN by decoupling the networking hardware from its（2）mechanism. This concept is similar to how software-defined networking implements（3）technology to improve data center management and operation. A key application of SD-WAN is to allow companies to build higher-performance WANs using lower-cost and commercially available（4）access, enabling businesses to partially or wholly replace more expensive private WAN connection technologies.SD-WAN technology supports（5）of Service (QoE) by having application-level awareness, giving bandwidth priority to the most critical applications.
问题1
A．paths
B．routes
C．tunnels
D．pipes
问题2
A．adaption
B．security
C．updating
D．control
问题3
A．decentralized
B．automation
C．intelligent
D．virtualization
问题4
A．private
B．Internet
C．internal
D．cross-domain
问题5
A．Quantity
B．Quality
C．Query
D．Queue