User's Guide

8400B Plus Data Module User’s Guide 555-020-709
Issue 2
November 1996
Isolating Problems Using Loopback Data Tests
D-13
Loop-Around Data Test Arrangement
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
Arrangement. If this succeeds, the problem is isolated to the network or to the
remote host equipment. The user is then instructed to call a Loop-Around Data
Test Arrangement at the host site (see Figure D-8
). If this call succeeds, then
the problem is not in the network between the switches.
Figure D-8. Using the Loop-Around Data Test Arrangement in a Network
Terminal
or
PC
Data Module,
PC/PBX,
or
Asynchronous
Data Unit
8400B Plus
Host
Data Module
Loopback
Plug
DCP
or ADU
Loop-Around Data
Test Arrangement
Two-Wire
DEFINITY
Communications
System
G3V2
or later
DEFINITY
Communications
System
G3V2
or later
020709_2.book Page 13 Friday, April 23, 1999 5:39 AM