3Com NETBuilder SI, Using Manual

Page: 136 / 212

136 A
PPENDIX
A: T
ROUBLESHOOTING
Before running the CSU/DSU loopback test:
■
Attach a console or Telnet to your bridge/router.
■
Cable your WAN port to the telco network.
■
Make sure the device you are connecting to supports V.54 loopback
and is in loopback mode.
To perform a V.54 loopback test on the built-in CSU/DSU, follow
these steps:
1 Diasble the path by entering:
SETDefault !3 -PATH CONTrol = Disable
2 Start the loopback test by entering:
SET -SYS V54Lback = YES
SET -SYS V54Lback = START
The loopback test runs for approximately one minute. If the loopback test
was successful, the following message is displayed:
V.54 data loopback succeeded
If the destination device does not respond, the following message is
displayed:
V.54 local loopback terminated - remote site not responding
If the data is corrupted and the line is not error free, the following
message is displayed:
V.54 data loopback failed - check for documented errors
If this message is displayed, contact your line provider for help.
If the local unit cannot transmit data at that particular time, the following
message is displayed, and you should try again later:
V.54 SCC Transmit failed
3 To stop the loopback test, enter:
SET -SYS V54Lback = STOP
4 If you want to enable V.54 detection so that a remote unit can initiate a
V.54 loopback test, enter:
SET -SYS V54Lback = YES
5 To disable V.54 detection, enter:
SET -SYS V54Lback = NO