Date Added: Jun 2012
In response to Internet emergencies, Internet resiliency is investigated directly through an Autonomous System (AS) level graph inferred from policy-compliant BGP paths or/and traceroute paths. Due to policy-driven inter-domain routing, the physical connectivity does not necessarily imply network reachability in the AS-level graph, i.e., many physical paths are not visible by the inter-domain routing protocol for connectivity recovery during Internet outages. The authors call the invisible connectivity at the routing layer, which can be quickly restored for recovering routing failures by simple configurations, as the potential routing diversities. In this paper, they evaluate two kinds of potential routing diversities, which are recognized as Internet eXchange Points (IXPs) participant reconnection and peering policy relaxation.