Performing A Loopback Test On A Serial Port - 3Com NETBuilder SI Using Manual

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PPENDIX ROUBLESHOOTING
Performing a
Loopback Test on a
Serial Port
This section describes how to perform a loopback test on a serial port.
Figure 14 shows the data flow that occurs when a loopback test is
performed on a serial line. A modem or CSU/DSU is required in this
configuration.
Figure 14 Serial Loopback Testing
Before running the serial loopback test, complete the following tasks:
Attach a console or Telnet to your bridge/router.
Place the modem or CSU/DSU in local loopback test mode. For
information, see the documentation that accompanies your modem
or CSU/DSU.
Verify the path and port number of the serial port you are testing by
referring to Table 14 or Table 15 on page 69.
To perform a loopback test on the serial port, follow these steps:
1 Set the line type to Leased using:
SETDefault !<path> -PATH LineType = Leased
2 Set the owner of the serial port you are testing to LoopBack using:
SETDefault !<port> -PORT OWNer = LoopBack
3 Select the loopback test mode by entering:
DLTest TestMode LoopBack
4 Specify the number of seconds that the test should run using:
DLTest TestDuration <seconds>
If you do not enter a value, the test will run indefinitely. However, use
caution when running the test for a specified duration. The test ends
abruptly as soon as the time duration expires, and a discrepancy between
the number of packets transmitted and the number received may result.
5 Start the serial loopback test by entering:
DLTest START