Expressing Different Traffic Models Using the LegoTG Framework

In this paper we demonstrate the ease of generating and modifying background traffic in testbed experiments through the traffic generation framework we developed, called LegoTG. LegoTG is a modular framework for composing custom traffic generation. It makes it easy to combine different traffic generators and traffic modulators (e.g., Delay models), and to port the same background traffic to different topologies. In addition to the framework, we have developed several traffic generation/modulation tools that can be used in LegoTG to generate realistic and highly controllable network and transport-level traffic. We build our demonstration around a series of simple experiments which reinforce how much background traffic matters in experiments and how different traffic models can drastically affect experiment results and research conclusions.