Diagnostic Parameters and Commands
Using diagnostics-related VT100 commands
MAX Administration Guide
B-7
Line LB already.
Cmd ignored.
Because the UnRq Corrupt CRC command acts similarly when requesting the remote end
cancel the loopback, the UnRq Corrupt CRC command is unavailable when the MAX unit
exits loopback mode.
Select the LB Counters status screen to display the number of transmitted frames as opposed to
the number of correctly received frames. The MAX unit continuously sends frames to the
remote end. When the unit receives a frame that matches the transmitted frame in size (and the
bytes of the received frame exactly match the bytes in the transmitted frame), it sends out a
new frame and increments the receive counter for that frame. When the unit receives a frame
that does not match the transmitted frame, it still sends out a new frame, but does not
increment the receive counter for that frame. Also, when the unit does not receive a frame
back, the timeout between two consecutive transmitted frames is about 4 seconds.
Press ESC to cancel the loopback function. The following message appears:
Line loopback terminated.
Corrupt CRC
The Corrupt CRC command causes the BRI-U interface to transmit inverted CRCs, until you
cancel the command. When the command is issued, the Far-End Block Error counter should be
viewed from the remote TA. The command is used to test the NEBE and FEBE counters, by
simulating transmission errors with artificially corrupted CRCs.
Uncorrupt CRC
The Uncorrupt CRC command cancels a previous Corrupt CRC command.
Rq Corrupt CRC
The Rq Corrupt CRC command requests NT1 to corrupt the CRC to artificially simulate
transmission errors. The command is used to verify that the block error counters are working,
or providing the right information. When you enter the command, check the Near-End Block
Error counter.
Rq Uncorrupt CRC
The Rq Uncorrupt CRC command requests NT1 to return to normal.
UnRq Corrupt CRC
The UnRq Corrupt CRC command requests NT1 to return to normal.
Clr NEBE
The Clr NEBE command clears the Near-End Block Error (NEBE) counter.
Clr FEBE
The Clr FEBE command clears the Far-End Block Error (FEBE) counter.