3Com NETBuilder SI, SuperStack II manual T1/FT1 Port 56x bridge/router, 46x

Performing Loopback Tests 141

Performing a Local This section describes how to perform a local line or payload loopback Loopback Test on the test using the loopback plug on the T1/FT1port on the model 46x and

T1/FT1 Port 56x bridge/router.

(46x and 56x)

Figure 13 shows the data flow that occurs when this loopback test is performed.

Figure 13 T1/FT1 Local Loopback Testing

T1/FT1 port

with loopback plug

Before running the T1/FT1 loopback test, attach a console or Telnet to your bridge/router.

To perform a local loopback test on the T1/FT1, follow these steps:

1Uncable the WAN port and insert the loopback plug that came with your system.

2Disable the WAN path by entering:

SETDefault !3 -PATH CONTrol = Disable

3Set the owner of the WAN port to loopback by entering:

SETDefault !3 -PORT OWNer = LoopBack

4Start the loopback test by entering:

LPBCK !3 -PATH LclLnLpbckSTART (for a line loopback test)

or

LPBCK !3 -PATH LclPyldLpbckSTART (for a payload loopback test)

If the number of received packets equals or approximately equals the number of transmitted packets, your line has passed the loopback test. If your line does not pass the test, verify that the software is configured correctly. Stop the loopback test by entering:

LPBCK !3 -PATH LclLnLpbckSTOP (for a line loopback test)

or

LPBCK !3 -PATH LclPyldLpbckSTOP (for a payload loopback test)