The current TCP/IP Internet may be modeled as an arbitrary interconnection of autonomous systems (AS). An AS is defined to be a collection of internetwork routers managed and administered by a single authority or organization. Typically an AS uses a single routing protocol within its boundaries to generate and propagate routing information. In this paper we analyse the performance of a technique that injects only partial reachability information derived from the inter-AS routing into the intra-AS routing.

This performance evaluation is based on traffic data obtained from the NSFNET backbone. We show, for instance, that injecting just 10% of the total inter-AS reachability information into the intra-AS routing permits the forwarding of at least 85% of the transit traffic without resorting to fallback fault mechanisms.