Scalability and Accuracy in a Large-Scale Network Emulator

This paper presents ModelNet, a scalable Internet emulation environment that enables researchers to deploy unmodied software prototypes in a configurable Internet-like environment and subject them to faults and varying network conditions. Edge nodes running user-specified OS and application software are congured to route their packets through a set of ModelNet core nodes, which cooperate to subject the trac to the bandwidth, congestion constraints, latency, and loss prole of a target network topology.

This paper describes and evaluates the ModelNet architecture and its implementation, including novel techniques to balance emulation accuracy against scalability. The current ModelNet prototype is able to accurately subject thousands of instances of a distrbuted application to Internet-like conditions with gigabits of bisection bandwidth. Experiments with several large-scale distributed services demonstrate the generality and effectiveness of the infrastructure.