An RFC 2544 tester is a specialised device used to evaluate the performance of network devices and networks based on the RFC 2544 standard, which defines a set of tests including throughput, latency, frame loss, burst handling, system recovery, and reset performance. These testers generate specific traffic patterns to stress the network or device under test, measure various performance metrics, and often include automation features for test execution and report generation. They are commonly used by network administrators and engineers to ensure that network equipment, such as switches and routers, meets performance standards and can handle expected loads effectively.