Chapter 13. Testing And Troubleshooting; Test Overview; Figure 13-1. Normal Operation Before Initiating Loopback Test - ADTRAN DSU IV ESP User Manual

Testing and Troubleshooting
Chapter 13

TEST OVERVIEW

The DSU IV ESP performs a variety of diagnostic functions that
isolate portions of the circuit to identify the problem source. Tests
may be initiated and terminated through the front panel, VT 100
terminal, SNMP, or Telnet. In asynchronous mode, AT commands
can control the testing from the DTE interface. For synchronous
operation, V.25 bis commands can provide test control.
The unit also responds to standard DDS network tests initiated
from telco test centers. In addition, it can run several tests such as
local and remote loopbacks to aid in problem isolation. See Figure
13-1.
DTE
TD
RD

Figure 13-1. Normal Operation Before Initiating Loopback Test

61204011L1-1
LOCAL
DSU/CSU
Tx Tx
Rx Rx
All diagnostic tests disrupt data flow.
DSU IV ESP User Manual
REMOTE
DSU/CSU
Tx
TELCO
Rx
DTE
Tx
TD
Rx RD
13-1