Avaya 8400B Plus User Manual

Page of 198
Loop-Around Data Test Arrangement
Issue 2   November 1996
D-11
If the user is successful in connecting to the Test Arrangement (the data typed 
in is echoing back) then be assured that the user’s desktop equipment and 
connection through the switch are functioning correctly. Help Desk personnel 
can than look elsewhere for the problem, saving valuable time in trouble 
isolation. 
A Loop-Around Data Test Arrangement can also be useful for modem pool calls. 
An off-premises user having trouble connecting to a host can call to use the 
Loop-Around Data Test Arrangement (see 
). Again, if the call 
succeeds, the problem is not in the modem pool.
Figure D-7. Using the Loop-Around Data Test Arrangement with Modem 
Pooling
The Loop-Around Data Test Arrangement is also useful for isolating problems in 
networks of digitally connected switches. The scenario is a user at one site 
needing to access a host at another site and having problems. The user is 
instructed by the Help Desk to call the local Loop-Around Data Test 
Terminal
DEFINITY
DCP
8400B Plus
Host
Data Module
Loopback
Plug
Modem
Pool
Network
or ADU
Communications
System
G3V2 or
later
Two-Wire
Loop-Around Data
Test Arrangement
Modem
or
PC