21(+1) Channel High-Density T1/E1/J1 Line Interfac.
IDT82P2821 - High-Density T1/E1/J1 Line Interface
21(+1) Channel High-Density T1/E1/J1 Line Interface Unit IDT82P2821 Version 3 February 6, 2009 6024 Silver Creek Valley Road, San Jose, California 951.