InternetSim: A Fast and Memory-Efficient Internet-Scale Inter-Domain Routing Simulator

Existing inter-domain routing simulators often suffer from low simulation accuracy, slow processing speeds, and high memory consumption, hindering their ability to perform large-scale Internet simulations. In this paper, we present InternetSim, a multi-threaded simulator for Internet-scale inter-domain routing. InternetSim enables incremental computation to deal with policy changes by some ASes, thus significantly accelerating multi-iteration context-continuous routing simulations. The memory efficiency is also improved by designing compact data structures for routing tables and out-of-memory errors are prevented by offloading the data to disk when necessary. Our simulator can complete an iteration of Internet-scale simulation within 13 hours (21× speedup compared to C-BGP) and can complete an ''incremental computation'' iteration within 15 seconds. The memory requirement is only 45% of C-BGP (without offloading) and the simulator can work well for Internet-scale simulations on a server with only 64GB if offloading is always enabled.