An Improved Approach for Eliminating the Loop in Hybrid Software Defined Network (SDN) Using Modified Bellman-Ford Algorithm

摘要

SDN is approaching its own structure of acceptance. Therefore, the increasing deployment of SDNs is being discussed as a possible approach, appearing in the development of the hybrid SDN networks. An foremost work in the hybrid SDN networks is bandwidth allocation, taking into account the integration of both SDN-enabled and conventional switches. The network loop in layer 2 switches is skipped in Spanning Tree Protocol (STP) by ceaselessly watching the network to trace all links and block the unwanted ones. Bridge loops will occur anytime there's a redundant Layer2 way between ends. By default, switches forward broadcast/multicast out all ports, other than the port from that the broadcast/multicast was delivered. Once a switch loop is brought in the network, broadcast messages are going to be broadcasted more often leading to broadcast storms. The Spanning-tree algorithm enforces a distributed divergent of the Bellman-Ford iterative algorithm that always looks for the optimal solution and selects an optimal influential switch anytime. In this paper we use controller's global network view for resolving loop problem in layer 2 network. SDN controller acts on broadcast packets received from switch-ports and host-ports differently that is if the broadcast packets received from host ports, the SDN controller broadcasts these packets to all ports and if broadcast packets is received from switch ports, only some switches broadcasts these packets on all ports instead of all switches.