Fibbing Based Topology Augmentation in Hybrid SDN

Traffic Engineering (TE) is an important mechanism for Internet service providers (ISPs) seeking to optimize network performance and traffic delivery. The routing optimization plays a key role in TE, which finds efficient routes to meet the desired network performance needs. Although SDN is attractive for its efficiency in TE, before the overall implementation, backward compatibility is very important for the network evolvement. To support the compatibility for hybrid SDN, in the prior literature, Fibbing- a method of achieving flexibility and robustness by centralized control based on distributed routing has been proposed. In Fibbing architecture, routers are enabled to calculate their own forwarding tables based on the new topology, by introducing virtual nodes and links into the original topology. In this paper, after the topology augmentation process, a Merger-Backward (MB) merging algorithm is proposed to reduce the size of the augmented topology and the network overhead. Results show that the proposed MB algorithm can merge more fake nodes and take shorter time to compute the augmented topology than Merger-Forward (MF) to some extent especially when the topology is large.