Abstract: The disclosure is related to a bandwidth management method performed in a network switch and a network system. In the method, a total bandwidth usage is firstly metered, and it is determined if the total bandwidth usage reaches a threshold for triggering a flow-limit process. This threshold acts as a bandwidth-usage threshold obtained by multiplying a total bandwidth by a meter-triggering threshold. The flow-limit process is triggered if the total bandwidth usage reaches the threshold; otherwise, the system will not intervene with the usage of bandwidth if the total bandwidth usage does not reach the threshold. In the flow-limit process, the class of a user is identified. Guaranteed bandwidth is provided for a prioritized user. A normal user will be restricted to using the bandwidth aside from the guaranteed bandwidth. The bandwidth provided for the normal user may exceed the available bandwidth based on an adjustable system parameter.

Abstract: The disclosure is related to a method for constructing hybrid network spanning trees, a method of redundancy, and a control system thereof. The method and system are adapted to a hybrid network system including at least one software-defined network (SDN) and at least one non-SDN network. In the method, a controller of the SDN is employed to collect network packets over the hybrid network. After analyzing the information carried in the network packets, the information relating to the topology can be obtained. Therefore, all the possible spanning trees can be constituted according to the topology. As well, the path delay and path bandwidth respectively for the SDN and non-SDN can also be obtained. The information allows the system to render utility function for every spanning tree. The most suitable spanning tree over the hybrid network system is applied. A mechanism of redundancy is also provided.