This report presents the Circuit Switching Module for ns-2. This mod-ule allows establishment of circuits (connections with reserved bandwidth) in the simulated packet-switched network. The Admission Control mecha-nism at the edges of the circuit decides which packets are allowed to use the circuit. The packets that do not fit into the circuit can be redirected into the packet-switched part of the network, to any outgoing link of the node. Moreover, a Stats Monitor was implemented to collect various packet statis-tics. The extension was validated using a six node butterfly network with a bidirectional circuit.