NetFPGA-based Precise Traffic Generation

Generating realistic network trac that reects dierent network conditions and topologies is crucial for performing valid experiments in network testbeds. Towards this goal, this paper presents Precise Trac Generator (PTG), a new tool for highly accurate packet injections using NetFPGA. PTG is implemented using the NetThreads platform, an environment familiar to a software developer where mul- tithreaded C programs can be compiled and run on the NetFPGA. We have built the PTG to take packets gener- ated on the host computer and transmit them onto a gigabit Ethernet network with very precise inter-transmission times. Our evaluations show that PTG is able to exactly reproduce packet inter-arrival times from a given, arbitrary distribu- tion. We demonstrate that this ability addresses a real prob- lem in existing software network emulators | which rely on generic Network Interface Cards for packet injections | and predict that the integration of PTG with these emulators would allow valid and convincing experiments which were previously dicult or impossible to perform in the context of network testbeds.