Implementation of smart-OSPF in hybrid software-defined network

The wide spread of smart phone causes the traffic demand in communication network increase rapidly. To address this increasing traffic, it should find appropriate routing to avoid link congestion. This allows effective resource utilization and improves network throughput in. Mishra et al. presented smart-open shortest path fast (S-OSPF) which is an extended scheme of conventional OSPF. This scheme aims to decrease congestion ratio by distributing traffic at only edge nodes. Intermediate nodes have the same functions as the conventional OSPF. S-OSPF achieves lower network congestion ratio compared to the conventional OSPF. In the other hand, it is difficult to add the extended S-OSPF functions to existing routers. In order to overcome the issue, we focus on the software-defined networking (SDN) technique. All routers are replaced in the SDN network with SDN switches, which have only data transfer function as a data plane, and these switches are controlled by a SDN controller. We are able to add extended functions for the switches. In S-OSPF, only edge nodes need to be replaced by SDN switches when other nodes obey conventional OSPF routing. The only edge nodes distribute the traffic incoming to the OSPF network from other networks, and other nodes operate OSPF routing. This technique can decrease network congestion ratio. According to the above reason, we propose hybrid software-defined networking (H-SDN). The concept of H-SDN is that to implement SDN system with conventional network system together. Here, in order to implement distributing traffic function on edge nodes in S-OSPF, we use H-SDN.