INTRODUCTION
1-4
1.4.2 Jumper-Selectable Ring Speed
The TRMIM-62A has a ring speed jumper located on the component
board for configuring the ring operating speed. Section 2.4 provides
instructions for setting the ring speed and information about conditions
under which the network’s default ring speed setting, specified on the
management module in the MMAC, may override the setting you
establish for the TRMIM-62A with the ring speed jumper.
1.4.3 Speed-Fault Protection
The TRMIM-62A has a speed-fault protection circuitry that prevents the
ring from beaconing in the event that a station configured to run at an
operating speed different than the TRMIM-62A’s operating speed is
connected to a TRMIM-62A lobe port. It prevents beaconing by
automatically disabling the port detecting the speed-fault violation. The
port’s corresponding LED indicates the port bypassed, and the station is
denied access to the ring. See Chapter 4 for more information about
LEDs.
1.4.4 Beaconing Protection
Protection against debilitating beaconing conditions is provided by the
Cabletron Systems Automatic Beacon Recovery Process (ABRP)
algorithm, included with the operating code of the management modules
installed in the MMAC with the TRMIM-62A. ABRP employs
multi-faceted recovery procedures in the event that a beaconing condition
originating at or from the TRMIM-62A or other components constituting
the network is detected by the management module. ABRP ensures that
defective network segments are swiftly isolated from operational network
segments.
NOTE
Check the 16Mb LED on the front panel of the TRMIM-62A to
determine the TRMIM-62A ring operating speed. To avoid
speed fault errors, ensure that the station inserting into the ring
is running at the same ring speed as the ring.
