The term postmodernism has been applied both to the era following modernity, and to a host of movements within that era (mainly in art, music, and literature) that reacted against tendencies in modernism.
A CSU/DSU (Channel Service Unit/Data Service Unit) is a hardware device about the size of an external modem that converts a digital data frame from the communications technology used on a local area network (LAN) into a frame appropriate to a wide-area network (WAN) and vice versa.he Data Service Unit (DSU) manages line control, and converts input and output between RS-232C, RS-449, or V.xx frames from the LAN and the time-division multiplexed (TDM) DSX frames on the T-1 line. The DSU manages timing errors and signal regeneration.
The CSU is a device that connects a terminal to a digital line. Typically, the two devices are packaged as a single unit. The dSU is a device that performs protective and diagnostic functions for a telecommunications line.You can think of it as a very high-powered and expensive modem.Such a device is required for both ends of a T-1 or T-3 connection, and the units at both ends must be set to the same communications standard.he dSU is a device that performs protective and diagnostic functions for a telecommunications line. You can think of it as a very high-powered and expensive modem. Such a device is required for both ends of a T-1 or T-3 connection, and the units at both ends must be set to the same communications standard.