Simulation-based Study of Ecn Performance in Red Networks

Explicit Congestion Notification is a recently proposed congestion avoidance scheme for IP networks. ECN uses marking packets instead of dropping them in case of incipient congestion. Avoiding packet drops saves network bandwidth and allows congestion signals to be propagated faster. In the paper, we present the results of detailed simulations that we have performed to assess the gain TCP applications could achieve from using ECN. We analyze both a single congested link and a more complex configuration. We also discuss head marking, a modification of router’s behavior that allows to faster propagate congestion signals.