Abstract: The invention relates to a method and apparatus for measuring and recording traffic at nodes in a data transmission network. In particular the invention provides a method of accurately counting individual activities of traffic at individual nodes. The invention is carried out in hardware by using a counter or number of counters which count individual activities of traffic on a preset activity condition being sensed at a node. The invention has the advantage that accurate measurement of traffic at a node is achieved. The invention is also easy to implement in hardware and overcomes the problems inherent in present software solutions.