3Com NETBuilder SI, Using Manual

Page: 139 / 212

Performing Loopback Tests 139
Performing a Remote
Loopback Test on a
56/64 Kbps CSU/DSU
Module
This section describes how to perform a loopback test on a 56/64 Kbps
CSU/DSU module.
Figure 12 shows the data flow that occurs when this loopback test is
performed.
Figure 12 CSU/DSU Module Loopback Testing
Before running the loopback test, complete the following tasks:
■
Attach a console or Telnet to your bridge/router.
■
Cable the CSU/DSU module to the network.
■
Verify the path and port number of the port you are testing.
The remote loopback test includes remote CSU Loopback and remote
DSU Loopback.
To perform a remote loopback test, follow these steps:
1 Set the baud rate of the port. The default setting of the Autobaud feature
is ON. You can turn off autobaud by setting the baud rate. For example,
to set the baud rate to 64 Kbps, enter:
SETDefault !3 -PAth BAud=64
To turn on autobaud, enter:
SETDefault !3 -PAth BAud=AUto
2 Enable the port by entering:
SETDefault !3 -PAth CONTrol=ENable
CSU/DSU Module
NETBuilder
Router
CONNECT
O F F
I C E
System WAN ISDN LAN
Line
Act
Line
Error
Link
Connect
Fault
Send
Active
Fault
Line
Active
Fault
Run
Load
Test
B1 B2
Status
Pwr Fwd
Alert