Channel Service Unit/Data Service Unit.It 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.
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. The 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. Connecting a T1/FT1 DSU/CSU HWIC to a Network. To connect a T1/FT1 DSU/CSU HWIC to a network, follow these steps: Step 1 Confirm that the router is turned off. Step 2 Connect one end of the straight-through RJ-48C-to-RJ-48C cable to the RJ-48C port on the T1/FT1 DSU/CSU HWIC. • Connecting a T1/FT1 DSU/CSU HWIC to a Network. The 1-port T1/fractionalized T1 (FT1) DSU/CSU HWIC (HWIC-1DSU-T1) includes an integrated DSU/CSU. The HWIC can be configured for either full T1 services or fractionalized T1 services Before connecting an HWIC to the network, ensure that the HWIC is installed in the router, the equipment is properly grounded, and you have the proper cables for connecting the HWIC to the network. This section describes the preparation necessary for connecting a T1/FT1 DSU/CSU HWIC to the network. • Connecting a T1/FT1 DSU/CSU HWIC to a Network. The 1-port T1/fractionalized T1 (FT1) DSU/CSU HWIC (HWIC-1DSU-T1) includes an integrated DSU/CSU. The HWIC can be configured for either full T1 services or fractionalized T1 services • Prerequisites for Connecting a T1/FT1 DSU/CSU HWIC to a Network. • Connecting a T1/FT1 DSU/CSU HWIC to a Network. The 1-port T1/fractionalized T1 (FT1) DSU/CSU HWIC (HWIC-1DSU-T1) includes an integrated DSU/CSU. The HWIC can be configured for either full T1 services or fractionalized T1 services From Wikipedia, the free encyclopedia. A CSU/DSU is a digital-interface device used to connect a data terminal equipment (DTE), such as a router, to a digital circuit, such as a Digital Signal 1 (T1) line. The CSU/DSU implements two different functions. The channel service unit (CSU) is responsible for the connection to the telecommunication network, while the data service unit (DSU) is responsible for managing the interface with the DTE. CSU/DSUs are made as separate products or are sometimes part of a T-1 WAN card. A CSU/DSU's Data Terminal Equipment interface is usually compatible with the V.xx and RS-232C or similar serial interface. Manufacturers of separate unit or integrated CSU/DSUs include Adtran, Cisco, and Memotec. The 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. CSU/DSU. A channel service unit/digital service unit (CSU/DSU) is a digital-interface device used to connect a router to a digital circuit like a T1. The CSU/DSU also provides signal timing for communication between these devices.  Prerequisites for Connecting a T1/FT1 DSU/CSU WIC to a Network. Before connecting a WIC to the network, ensure that the WIC is installed in the router, the equipment is properly grounded, and you have the proper cables for connecting the WIC to the network. This section describes the preparation necessary before connecting a 56/64-kbps DSU/CSU WIC to the network. Connecting a T1/FT1 DSU/CSU WIC to a Network. To connect a T1/FT1 DSU/CSU WIC to a network, follow these steps: Step 1 Confirm that the router is turned off. 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.
http://searchnetworking.techtarget.com/definition/CSU-DSU http://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/ic/hardware/installation/guide/DSU_T1_HWIC.html http://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/ic/hardware/installation/guide/DSU_T1_HWIC.html http://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/ic/hardware/installation/guide/DSU_T1_HWIC.html https://en.wikipedia.org/wiki/CSU/DSU http://searchnetworking.techtarget.com/definition/CSU-DSU http://docwiki.cisco.com/wiki/Introduction_to_WAN_Technologies http://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/ic/hardware/installation/guide/dsu_wic.html http://www.webopedia.com/TERM/C/CSU_DSU.html
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