ADTRAN designs, develops, and manufactures ADvanced TRANsmission products for high-speed digital communications. ADTRAN commitment to total customer satisfaction requires continually developing and improving products to meet changing needs while maintaining the highest level of quality. That's why a complete collection of modular and scalable ADTRAN solutions is provided with a broad range of options for management, network, and local loop interfaces.The smart 16/16e rackmount T1 DSU/CSU terminates a DS1 signal from the carrier into a V.35 DTE interface.