266CHAPTER 17: FUNDAMENTAL CT3 INTERFACE CONFIGURATION COMMANDS

Example # Enable periodical alarm signal detection on CT3 interface T3 2/0.

<Sysname> system-view

[Sysname] interface t3 2/0

[Sysname-T3 2/0] alarm detect

# Enable CT3 interface T3 2/0 to send AIS alarm signals.

<Sysname> system-view

[Sysname] interface t3 2/0

[Sysname-T3 2/0] alarm generate ais

bert (CT3 interface view)

Syntax bert pattern { 2^7 2^11 2^15 qrss } time number [ unframed ]

undo bert

View CT3 interface view

Parameter pattern: Sets a bit error rate test (BERT) pattern, which could be 2^7, 2^11, 2^15, or QRSS.

2^7: Two to the seventh power, length of the transmitted BERT pattern in bits.

2^11: Two to the eleventh power, length of the transmitted BERT pattern in bits.

2^15: Two to the fifteenth power, length of the transmitted BERT pattern in bits.

qrss: Two to the twentieth power, length of the transmitted BERT pattern in bits. In this pattern, the presence of 14 consecutive zeros is not allowed.

time number: Sets the duration of a BERT test, in the range 1 to 1440 minutes.

unframed: Sets the test pattern to cover the overhead bits of the frame.

Description Use the bert command to start a BERT test on the CT3 interface.

Use the undo bert command to stop the BERT test running on the CT3 interface.

ITU O.151, ITU O.153, and ANSI T1.403-1999 define many BERT patterns, among which, the CT3 interface supports only 2^7, 2^11, 2^15, and QRSS 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 bit error rate, and by so doing helps you identify 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 controller t3 command.

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3Com MSR 30, MSR 50 manual Bert CT3 interface view, # Enable CT3 interface T3 2/0 to send AIS alarm signals