Control plane programmability, primarily enabled by SDN/OpenFlow, has brought new impetus to already consolidated management and planning practices in the area of computer networks. However, applications that require high responsiveness and demand more dynamic mechanisms executing beyond the control plane can only be effectively exploited through interactions with the data plane, where decisions and reactive responses can be made at line rate. P4 achieves this goal by providing directives that allow a certain level of control over the hardware that performs packet forwarding tasks, bringing programmability to the data plane. In this paper, we present a multipath routing strategy that takes full advantage of a hybrid SDN/OpenFlow and P4 architecture. In the data plane, P4 and the Flowlet abstraction are used to actively perform load balancing and routing over multiple asymmetric paths, in addition to monitor active links. In the logically centralized control plane, the overall view of the network is leveraged to perform more elaborate passive tasks, which include mapping paths, configuring devices and updating routes asynchronously. Experimental evaluations are conducted in which we analyze different strategies for choosing the routes that provide the best results based on RTT values received from the switches.

The use of network infrastructure resources in an efficient manner is a necessity that requires the employment of a range of sophisticated techniques. Multipath is already designed as good practice to achieve load balancing and some level of resiliency. However, in order to achieve high efficiency, strategies need great responsiveness to network events. In this paper we present an approach that relies on the Flowlet abstraction to manage the division and monitoring of network flows. Through a simple idea, we add a function that dynamically monitors and acts in the data plane to find the minimum possible interval that allows the alternation of a flow between routes without causing adverse effects. We performed the evaluation using P4 as an engine that acts on the data plane.