NetFPGA-based Precise Traffic Generation

Generating realistic network traffic that reflects different network conditions and topologies is crucial for performing valid experiments in network testbeds. Towards this goal, this paper presents Precise Traffic 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 multithreaded C programs can be compiled and run on the NetFPGA. We have built the PTG to take packets generated 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 distribution. We demonstrate that this ability addresses a real problem 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 difficult or impossible to perform in the context of network testbeds.