DESC: The ADTRAN TSU LT is a low cost, full-featured T1/FT1 Data Service/ Channel Service Unit (DSU/CSU). The TSU LT provides an interface between T1 or Fractional T1 service and the end user's Data Terminal Equipment (DTE) for applications such as LAN to LAN bridging, Frame Relay circuit termination and videoconferencing. The TSU LT provides access to traditional dedicated point-to-point T1 services as well as network termination for Frame Relay.