Csu/Dsu Basics; Dsu Functions; Csu Functions - Multitech MT56DSU2 Owner's Manual

MT56DSU2 Owner's Manual
MultiDSU56K
SD RD CD 96 48 CTS NS DOS
56 19.2 RTS TM Multi-Rate DSU/CSU
Send Rcv Carrier 56K 19.2K 9600 4800 Clear Request NoSgnl Outage Test
Figure 1-1. Multi-Tech System's MultiDSU56K

1.4 CSU/DSU Basics

A DSU (Data Service Unit) and a CSU (Channel Service Unit) are typically connected to provide
the interface between DTE (data terminal equipment) and the DDS (Digital Data Service) or other
four-wire network.
The DSU is used to process serial synchronous or asynchronous digital data over the DDS
network or other four-wire unloaded twisted-pair wiring network.
The MultiDSU56K can transmit data at 56000, 19200, 9600, 4800 and 2400 bps in multi-point
and point-to-point applications.
The MultiDSU56K contains the functions of a Data Service Unit (DSU) and a Channel Service
Unit (CSU) in a single package.

1.4.1 DSU Functions

The DSU encodes data as pulses on the communications line by converting the customer data
stream to bipolar format for transmission over the digital network.

1.4.2 CSU Functions

The CSU is used to terminate the digital circuit at the customer site. It performs line conditioning
functions, ensures network compliance with FCC rules, and responds to test commands (either
from the telco central office (CO) or from the CSU).
The figure below shows the MultiDSU56K in a basic DDS network installation.
DDS
Network
MultiDSU56K
DTE DTE
MultiDSU56K
Figure 1-2. Basic DSU/CSU Configuration
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