Scalable Network Emulation - The NET Approach

Network emulation is an efficient method for evaluating distributed applications and communication protocols bycombining the benefits of real world experiments and networksimulation. The process of network emulation involves the executionof connected virtual nodes running the software under test ina controlled environment. Our Network Emulation Testbed (NET) achieves high scalability by combining efficient node virtualization and adaptive virtual time. In this paper, we provide an overview of our system. First, we introduce our efficient emulation architecture. Second, we present our approaches (NETplace and NETbalance) to minimize the runtime of the network experiments. The idea of NETplace is to minimize the load of the testbed by calculating an initial placement of virtual nodes onto the testbed nodes. During the runtime of the experiment NETbalance adapts this placement to changed resource requirements of the software under test. Finally, we introduce NETcaptain, a graphical user interface to setup, control and visualize network experiments.