Quantifying ases multiconnectivity using multicast information

Abstract

Redundant connectivity (or multiconnectivity) between adjacent autonomous systems (ASes) is important for interdomain traffic engineering and fast recovery in case of failures. However, the redundancy of ASes business relationship links has not been quantitatively studied, mainly due to the difficulty of obtaining relevant data. In this paper, we show that the mrinfo multicast monitoring tool can provide useful data about the Internet topology and such redundant links in particular. Our analysis relies on more than four years of daily queries to about ten thousand routers mapped into more than two hundred ASes. We demonstrate that peering links between ASes are frequently redundant. In particular, our analysis shows that more than half of the studied ASes pairs are connected through multiple physical links. We then refine our analysis by considering the different types of ASes and their business relationships. A particular result of our analysis is that at least 75% of the peer-to-peer relationships between adjacent Tier-1 ASes are redundant, i.e., the connections between these ASes involve several physical links. Our analysis is conservative, providing so a lower bound, as some links might not be seen by mrinfo due to ISPs filtering policies.

Comparing Overlapping Properties of Real Bipartite Networks

“…Internet [15,8]: In this network, ⊥ nodes stands for Internet routers and ⊤ nodes indicates the presence of Ethernet switches whose purpose is to induce indirect connections among routers. The dataset used in this study corresponds to a measurement campaign conducted in September 2006.…”

“…It relies on recent developments in topology discovery [8,7] that allows for revealing two layers in the Internet structure. The model remains simple: it only takes as input the node degree sequence for both layers and randomly generates a bipartite graph respecting those distributions.…”

BGP-XM: BGP eXtended Multipath for transit Autonomous Systems

“…Furthermore, in this analysis we do not Accurate data about the redundant interconnections between two neighboring AS is hard to obtain [5,35]. For that reason, it is not possible to include them in the analysis and in our model we consider that there is at most one link between two ASes.…”

“…According to [5,13], a large portion of the existing path diversity is dismissed by the constrains of BGP Multipath and more relaxation of the path selection rules should be beneficial. The work presented in [40] is similar to our approach in the sense that it relies on a path aggregation technique to advertise the multipath set to legacy routers.…”

“…Even after removing all the paths which are not usable according to the business relationships established among the connected ASes, a large number of paths traversing different sequences of ASes exists between most of the Internet sites [4]. Additional redundancy comes from the use of multiple links between pairs of neighboring ASes [5].…”