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The DAG Project


The DAG Project began within the University of Waikato networking research group (now known as the WAND Group) in 1994 to develop network measurement cards that could capture packet headers with very high precision timing. The project was successful, resulting in hardware that was flexible, efficient and relatively inexpensive which could capture at line rates of up to 622Mbps with a timestamp resolution of less than 1 microsecond. DAG cards were used to capture a number of now popular research tracesets, including the Auckland traces. In 2001, Endace Measurement Systems was formed to commercialise the DAG project.


Endace is now responsible for the distribution and support of the DAG hardware and drivers. Endace also provide a software API that allow programmers to interface with a DAG card and a set of tools, called dagtools, that support trace capture using the DAG card and analysis of ERF traces. Prior to commericialisation, the dagtools were publicly available so that researchers could easily process the tracesets that had been captured using DAG cards. Access to the dagtools is now limited to Endace customers.

Reading DAG traces

The WAND Group has developed an open-source software library called Libtrace which can read a variety of trace formats, including the Extensible Record Format (ERF) traces that are produced by DAG cards. Libtrace also provides a set of tools that can perform most simple trace capture and processing tasks. In addition, libtrace can be used to perform live capture using a DAG card directly using the DAG software API, if available. We strongly recommend that researchers use libtrace to read tracesets captured using DAG cards. A full list of trace formats supported by libtrace can be found in the Libtrace Wiki.

Please note that libtrace is developed and supported entirely by WAND and is not directly affiliated with Endace Measurement Systems.