  Software-Defined Data Centers (SDDC) extend virtualization, software-defined
networking and systems, and middleboxes to provide a better quality of service
(QoS). While many network flow routing algorithms exist, most of them fail to
adapt to the dynamic nature of the data center and cloud networks and their
users' and enterprise requirements. This paper presents SMART, a
Software-Defined Networking (SDN) middlebox architecture for reliable
transfers. As an architectural enhancement for network flows allocation,
routing, and control, SMART ensures timely delivery of flows by diverting them
to a less congested path dynamically in the software-defined data center
networks. SMART also clones packets of higher priority flows to route in an
alternative path, along with the original flow. Hence SMART offers a
differentiated QoS through varying levels of redundancy in the flows.
