Board-to-board test unit for a digital subscriber line

摘要: An upstream PCM link accommodated in a new switch is bridged to downstream an old the normal operating condition. A test unit sends number of subscriber be tested and switches. The call control information corresponding directory as process. monitor monitors whether or not properly received through extractor provided standard component. Thus, board-to-board can conducted by combining function extracting with plurality signals multiplexed physical links without excessively increasing load switch.