IBM ATM OC-3c User Manual

Page 104

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D-10

A

PPENDIX

D: T

ROUBLESHOOTING

Is the ILMI Connection Set Up Correctly?

To communicate with each other, edge-devices must
use the same Interim Local Management Interface
(ILMI)
connection.

On the ATM Module the ILMI connection is specified in
the ILMI VCC field, as shown in Figure D-6 on page D-9.

Consult the user guide that accompanies the ATM
Switch to find out where the ILMI connection is
specified.

Is the ILMI connection the same for the ATM Module
and the ATM Switch?

Yes — go to step 20.
No — go to step 19.

Make ILMI VPI/VCI Same at Both Ends of the Link

Ensure that the ILMI VPI and VCI values are the same
on both the ATM Module and the relevant ATM
Switch port.

In most cases you should probably use the standard
ILMI VPI/VCI values: VPI = 0, VCI = 16.

Are the MAX VPI and VCI Bits Compatible?

To communicate with each other, edge-devices must
use compatible MAX VPI Bits and MAX VCI Bits
settings. The MAX VPI Bits and MAX VCI Bits settings
determine how many bits are used within each cell
header to define the value of the VPI and VCI. The VPI
and VCI values identify the connection.

Some ATM devices automatically negotiate the
number of bits used for the VPI and VCI fields. In this
situation you would only change the number of bits if
you want to increase the number of bits used by both
ATM devices.

On the ATM Module these settings are shown on the
ATM Module Configuration screen, see Figure D-6 on
page D-9.
The default setting for MAX VPI Bits is 3,
and 8 for MAX VCI Bits.

Refer to the ATM Switch user guide to find out how
to locate these settings on your ATM Switch.

Are the settings compatible?

Yes — If you are still experiencing problems, contact
Technical support.

No — go to step 21.

Make the MAX VPI and VCI Bits Compatible

Ensure that the MAX VPI Bits and MAX VCI Bits
settings are compatible.

Is the LEC Operational?

Using the ATM VLAN LEC Status screen, described in
step 9, check the Last LEC Failure Reason.

Is the Last LEC Failure Reason field set to None?

Yes — the LEC is operational. Go to step 25.
No — go to step 23.

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