Chapter 1:
Introduction
Page 1-4
MicroMMAC Installation Guide
1.5 MicroMMAC FEATURES
Repeater Functionality
The MicroMMAC fully conforms to the IEEE 802.3 Repeater, AUI, and
10BASE-T specifications, and provides the flexibility to connect
networks using IEEE 802.3, Ethernet Version 1 or Version 2 equipment.
The MicroMMAC transmits retimed data packets, regenerates the
preamble, extends fragments, and arbitrates collisions.
The MicroMMAC automatically partitions problem segments, and
reconnects repaired segments to the network. This feature minimizes the
impact on network operation resulting from a problem on one segment by
isolating the problem segment. Only devices on the problem segment are
affected. When the problem is solved, the MicroMMAC automatically
reconnects the isolated segment to the network.
Polarity Detection and Correction
Each twisted pair port on the MicroMMAC incorporates a Polarity
Detection and Correction feature. This feature allows the MicroMMAC to
pass data regardless of the polarity of the twisted pair segment’s receive
link. Cabletron Systems does not recommend operating in this condition.
If you discover this condition, remove the segment from the network and
wire it correctly. This reduces the potential for problems in the future if
equipment changes are made.
Local Management
Local Management allows you to manage the MicroMMAC and all its
attached segments. It also provides full packet and error statistics for the
entire stack, individual device, or individual port. You access Local
Management by attaching a DEC VT320 terminal or a PC using VT320
emulation software to the MicroMMAC’s RJ45 COM 2 port. Refer to the
MicroMMAC Local Management User’s Guide
for instructions on how to
use Local Management.
LANVIEW LED
Cabletron Systems LANVIEW status monitoring and diagnostics system
is a troubleshooting tool that helps diagnose power failures, collisions,
cable faults, and link problems. LANVIEW LEDs are conveniently
located on the MicroMMAC front panel.
