The Ultra OC-3/STM-1 card (PCI) plugs into a PC expansion slot for analyzing, testing, simulating, and monitoring OC-3 and STS-1 signals. The Ultra OC-3/STM-1 card may be used in conjunction with GL's Ultra T1 Card, Ultra E1 Card and Ultra T3 Card in the same PC to provide a complete OC-3/STM-1, STS-1/STM-0, DS3, DS1, E1 and DS0 testing solution.