A comparative study of IP-based and ICN-based link-state routing protocols in LEO satellite networks

The low earth orbit (LEO) satellite constellations exhibit dynamic network topology due to the intermittent inter-satellite links (ISLs). To ensure efficient data delivery in LEO satellite networks, it is crucial to find an appropriate routing protocol that is capable of accommodating the dynamic topology. In this paper, we consider two typical IP-based and ICN-based link-state routing protocols (i.e., OSPF and NLSR, respectively) and investigate the adaptability in LEO satellite networks. Specifically, we first analyze and compare their advantages and disadvantages in LEO satellite networks from the perspectives of link state detection, link state synchronization, and packet forwarding scheme. To verify our analysis, we conduct extensive packet-level experiments on OMNeT++. Our analysis and simulation unveil several critical insights. First, IP-based OSPF (following push-based communication) outperforms the ICN-based NLSR (following pull-based communication) in terms of the routing convergence and control overhead in satellite networks. Specifically, OSPF converges faster than NLSR up to 90.8% and yields less control overhead under the Iridium constellation. Second, the ICN-based NLSR (supporting Interest aggregation and in-network caching) outperforms the IP-based OSPF in terms of the packet delivery performance, especially under the content-sharing traffic pattern (up to 206%). However, the occasional ISL failure significantly reduces the content delivery performance of NLSR under the point-to-point traffic pattern. To sum up, our study unveils the necessity of properly integrating IP-based and ICN-based link-state routing paradigms in LEO satellite networks.