Command Reference Guide

3Com Router 5000 Family and Router 6000 Family ft1 bert (T1-F Interface) ● 179
Command Reference
ft1 bert (T1-F Interface)
Purpose Use the ft1 bert command to start a BERT test on the T1-F interface.
Use the undo ft1 bert command to stop the BERT test running on the T1-F
interface.
Syntax ft1 bert pattern { 2^15 | 2^20 } time minutes [ unframed ]
undo ft1 bert
Parameters pattern
Sets a bit error rate test (BERT) pattern, which could be
2^15 or 2^20.
2^15
Two to the fifteenth power, length of the transmitted
BERT pattern in bits.
2^20
Two to the twentieth power, length of the transmitted
BERT pattern in bits.
time minutes
Sets the duration of a BERT test. Valid values are 1 to
1440 minutes.
unframed
The test pattern covers the overhead bits of the frame.
Example Run a 10-minute 2^20 BERT test on T1-F interface 0/0/0.
[Router-Serial0/0/0] ft1 bert pattern 2^20 time 10
View This command can be used in the following views:
■ T1-F Interface view
Description ITU O.151, ITU O.153, and ANSI T1.403-1999 define many BERT patterns, among
which, the T1-F interface supports only 2^15 and 2^20 at present.
When running a BERT test, the local end sends out a pattern, which is to be looped
over somewhere on the line and back to the local end. The local end then checks the
received pattern for the bit error rate, and by so doing helps you determine whether
the condition of the line is good. To this end, you must configure loopback to allow
the transmitted pattern to loop back from somewhere on the line, for example, from
the far-end interface by placing the interface in far-end loopback.
You may view the state and result of the BERT test with the display ft1 serial
command.