Distributed Multicast Traffic Engineering for Multi-Domain Software-Defined Networks

Previous research on SDN multicast traffic engineering mainly focused on intra-domain optimization. However, the main traffic on the Internet is inter-domain, and the selection of border nodes and sharing of network information between domains are usually distributed but ignored in previous works. In this article, we explore multi-domain online distributed multicast traffic engineering (MODMTE). To effectively solve MODMTE, we first prove that MODMTE is inapproximable within $|D_{\max }|$ , which indicates that it is impossible to find any algorithm with a ratio better than $|D_{\max }|$ for MODMTE, and $|D_{\max }|$ is the maximum number of destinations for a multicast tree. Then, we design a $|D_{\max }|$ -competitive distributed algorithm with the ideas of Domain Tree, Dual Candidate Forest Construction, and Forest Rerouting to achieve the tightest performance bound for MODMTE. Experiments on a real SDN with YouTube traffic manifest that the proposed distributed algorithm can reduce more than 30% of the total cost of bandwidth consumption and rule updates for multicast tree rerouting compared with the state-of-the-art algorithms.