REQUIREMENTS AND SPECIFICATIONS
2-4
2.4.1 Management Configuration Overrides
A Token Ring management module in the MMAC “remembers” the
position and ring speed setting for each Token Ring module in the hub
that it controls. The default response by any Token Ring management
module to a TRMIM-62A configured to run at a ring speed incompatible
for the slot in which the board is initially installed is to bypass it from the
ring. Under certain circumstances, some management modules will
override a different JP1 ring speed setting for the TRMIM-62A. Other
management modules, however, bypass the TRMIM-62A every time it is
installed or reinstalled in the MMAC with a ring speed incompatible with
the slot’s original configuration.
In either a
TRMM-
or a
TRMMIM-managed
ring, the
management-specified ring speed overrides the JP1 ring speed setting on
a TRMIM-62A under the following conditions:
•
A TRMIM-62A is removed from the MMAC and then reinserted into
its original slot with a different JP1 ring speed setting.
For example, the TRMIM-62A JP1 jumper is changed from the 16
Mbps setting, which is stored in the management module’s memory
when the MIM is originally installed, to a 4 Mbps setting. When it is
reinserted in the MMAC, the 16 Mbps ring speed setting prevails over
the 4 Mbps setting. The TRMIM-62A continues to run at 16 Mbps,
even though its JP1 ring speed jumper is now set at 4 Mbps.
•
A replacement TRMIM-62A with a ring speed setting different from
the original MIM is installed in the same slot.
To nullify the management override and establish an isolated ring
supported by the TRMIM-62A running at a different ring speed in the
MMAC, you can try any of the following procedures:
•
Reinsert the TRMIM-62A in a slot other than its original slot after you
have changed the JP1 setting.
•
Use Local Management for the TRMM or TRMMIM to temporarily
put the TRMIM-62A in “Auto” mode before switching back to the
“Management” mode after you have changed the JP1 setting and
reinserted the TRMIM-62A back into its original slot.
•
Temporarily insert a different type of MIM in the TRMIM-62A slot
before reinserting the TRMIM-62A after you have changed the JP1
setting.
