ATM Tips
Issue 5 October 2002
141
555-233-119
—
Oper Status
should be
up
. If it is
down
, there is likely a loss of
signal on the port in question (
State
of
present
), or the A500
does not recognize the port board (
State
of
invalid
). This
command detects a continuity problem only with the Receive
(right-hand) fiber; it does not detect the state of the Transmit
(left-hand) fiber.
Possible Causes
■
The fiber is disconnected from the A500 and/or the TN230Xs.
■
The Transmit and Receive fibers are swapped at the A500 or the TN230X
(but not both).
■
There is a break in the fiber.
■
The TN230X is not transmitting a carrier (not inserted, not powered, or not
administered). See
‘‘ATM-BCH (ATM B-Channel Trunk)’’
.
■
Hardware safety interlocks on optical transceivers may cut transmitter
power if no carrier is received, so lack of a receive carrier could indicate a
transmitter problem at the same end.
■
The A500 does not recognize that there is a port board in the slot. It may
be necessary to re-administer the A500 port boards. See the Cajun A500
Quick Reference for further information.
Recommended Action
1. Plug in, swap, repair, or replace the fiber as necessary.
2. Verify that the port board is inserted.
SONET Layer
Are SONET frames reaching the A500?
Is the A500 port’s green RX LED solid off, indicating no cell traffic?
1. Enter show stats sonet port on the A500 console.
Screen 36 on page 142
shows the screen output.
NOTE:
The following examples point to port A1.2 as the port of interest.