DynPaC: A Path Computation Framework for SDN

The DynPaC (Dynamic Path Computation) framework has been designed to provide resilient on-demand Layer 2 services with bandwidth constraints in Software-Defined Networks, more specifically in Open Flow networks. It has been implemented using the Open Daylight platform as base Open Flow controller, which has been extended with custom modules that provide resiliency, scheduling, monitoring and network resource optimisation. Thanks to an advanced Path Computation Element, DynPaC is able to take into account the available bandwidth in the network to assign the best possible path, in this case the shortest one, to the requested services. Furthermore, DynPaC supports service reservation, and takes into account already reserved services at the time of computing the paths for new service demands thanks to a powerful and novel scheduling mechanism based on network snapshots. In addition, DynPaC is able to maximise the network resources´ utilisation through a service reallocation and disaggregation mechanism. Of special interest is the flow disaggregation algorithm, which makes use of the Open Flow´s high granularity to divide the original service into the minimum number of sub-services and reallocate them in the network to free enough network resources to accept new service demands.