Cabletron Systems MICROMMAC-22T, User Manual

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INTRODUCTION
1-2
1.2 MicroMMAC-T FEATURES
This section provides an overview of MicroMMAC-T features.
1.2.1 Lobe Port Features
This section overviews lobe port features.
Repeater Circuitry
Repeater circuitry in the MicroMMAC-T enables lobe ports to regenerate,
reshape, and filter the incoming signal, permitting UTP lobe cable lengths
of up to 120 meters and STP lobe cable lengths up to 150 meters for a
16 Mbps network.
Speed Fault Protection
The MicroMMAC-T automatically disables any lobe port that detects a
station connected to it from trying to enter the ring at the wrong
operational speed. This prevents the station from causing a beaconing
condition on the ring. A lobe port’s associated Lobe Port Status LED
blinks red to indicate that the port has detected a speed fault violation and
has been put into the bypassed mode. (See
Section 5.1 for information
about monitoring the MicroMMAC-T using LANVIEW LEDs.)
Lobe Port To Ring Port Conversion
Lobe ports can be converted through management to Ring Out (RO)
ports, supporting connection
only to passive Multi-Station Access Units
(MSAUs) such as the Cabletron Systems TRC-800 or the IBM 8228.
1.2.2 Management Capabilities
The MicroMMAC-T supports both in-band and out-of-band access to
embedded management applications and MIBs.
Local Management (LM)
LM comprises a set of basic monitoring and configuration applications
you can use to manage up to 120 ports on the combined MicroMMAC-T
and STH stack. You can gain out-of-band access to LM using a VT-series
terminal or a PC running a VT-series emulation program from either a
direct cable connection or remote modem connection to either of the
MicroMMAC-T’s front-panel RS-232C COM ports.