33.2 Architecture

The purpose of Session-level packet distribution is to speed up simulations and reduce memory consumption while maintaining reasonable accuracy. The first bottleneck observed is the memory consumption by heavy-weight links and nodes. Therefore, in SessionSim (Simulator for Session-level packet distribution), we keep only minimal amount of states for links and nodes, and connect the higher level source and receiver applications with appropriate delay and loss modules. A particular source in a group sends its data packets to a replicator that is responsible for replicating the packets for all the receivers. Intermediate loss and delay modules between this replicator and the receivers will guarantee the appropriate end-to-end characteristics. To put it another way, a session level simulation abstracts out the topology, routing and queueing delays. Packets in SessionSim do not get routed. They only follow the established Session.