Abstract: A novel high speed telecommunications testing apparatus and method which utilizes field programmable gate arrays to produce dynamic test modules for DS1, DS3, SONET and ATM signals interconnected by a high speed switching fabric. The high speed switch permits the direct exchange of signals from one test module to another thereby permitting simultaneous testing of different communications line protocols and further provides for multiple tests on a single data stream. Individual line interfaces are provided for DS1, DS3, and SONET lines which terminate and frame incoming and outgoing signals. Data exchange between modules in accomplished through the high speed switch fabric.