Route servers for inter - domain routing 1

Internet transmission and switching facilities are partitioned into different administrative domains. To effect routing between domains, domain border routers establish pairwise peering sessions and exchange routing information at exchange points. An alternative arrangement, in which each border router at an exchange point peers only with a Route SerÕer, provides some operational benefits. From a set-theoretic characterization of border router behavior, we derive a set-theoretic expression that completely and succinctly characterizes Route Server functionality. Performance measurements from our Route Server implementation reveal that the storage requirements of Route Servers can be much larger than that of a typical border router. We discuss a variety of techniques that can, in some cases, reduce Route Server storage requirements by a factor of five or more. q 1998 Elsevier Science B.V. All rights reserved.