The DS2149 is a fully integrated LIU for longhaul or short-haul T1 applications over twistedpair installations. It interfaces to two twisted-pair lines--one pair for transmit and one pair for receive through an appropriate network interface. The device can be configured for control through software or hardware mode. Software control is accomplished over a serial port, in hardware mode; individual pin settings allow standalone operation. The device provides a precise, crystal-less jitter attenuator that can be placed in either the transmit or receive path.