FPGA-based Ethernet sniffer for Real-Time networks

Abstract

This paper presents an Ethernet sniffer based on dedicated hardware, able to carry out the timestamping of network events with a level of resolution and precision compatible with the specific needs of real-time protocols. The sniffer is basedin FPGA technology, and autonomously stores in local memory the received messages data and associatedinformation (timestamps and size). This data is then fed to the host computer, via an USB connection, and stored in a file format compatible with Wireshark. This allows using standard tools to subsequently analyze the traffic. Furthermore, in the scope of this work it was also developed custom tools to automate the analysis of timing propertiesof the traffic, including the generation of graphicsand statistical data, which are common operationsin the analysis of real-time protocols. The paperincludes experimental results of a prototype implementationshowing that this tool permits meticulous temporal measurements, with a resolution of 10ns and a maximum error of 100ns, which improve the results obtained with standard softwarebased applications by over one order of magnitude.