The portable J2126A transmission test set has been designed to test the latest aggregation platforms, reduce installation and maintenance test time, and decrease the overall cost of test. As the first multi-rate transmission test set to incorporate all-channel testing technology, users can now simultaneously monitor up to 192 network paths within a SONET/SDH transport signal in just two key presses. This latest test technology eliminates traditional, labor-intensive sequential testing without compromising measurement accuracy. The transmission test set also automatically monitors the line signal and all STS/AU channels (up to 192) for errors, alarms and pointer activity. Channels carrying revenue-generating services are identified, as are path routing errors within the network. The J2126A supports all line rates up to 2.5 Gb/s (OC-48/STM-16).