rXstp: A Topology Discovery Mechanism Based on Rapid Spanning Tree for SDN In-Band Control

Topology discovery is a key issue in software-defined networking (SDN). Since there is no dedicated control network between the switch and the controller in the in-band control mode, part of the control traffic needs to be transmitted on the network data link, which increases the difficulty of the switch and the controller to establish a control channel and SDN topology discovery. In this paper, a rXstp mechanism is proposed, which can use the Layer 2 forwarding of the switch to quickly connect to the in-band controller. At the same time, SDN with the preventing loop mechanism enabled, the network topology can be collected more efficiently and completely. Finally, through network simulation, the performance evaluation of rXstp was completed. Experiments show that rXstp is superior to the current topology discovery protocol.