INTRODUCTION
Page 1-4
The HUB 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. As an IEEE 802.3 compliant repeater, the HUB
transmits re-timed data packets, regenerates the preamble, extends
fragments, arbitrates collisions and automatically partitions problem
segments, and reconnects non-problem segments. This feature
minimizes the impact on network operation resulting from a problem
on one segment by isolating the problem segment so that only the
devices on that segment are affected. When the problem is solved, the
problem segment is automatically reconnected to the network.
Since the HUB utilizes polarity detection and correction, the twisted
pair connections are not sensitive to signal polarity. The network will
still function properly with the (+) and (–) lines within a pair
reversed. The LINK LED for the port with reversed polarity will
flash to indicate this condition. Operating in this condition is not
recommended and if this condition is discovered, the segment should
be removed from the network and wired correctly by a technician.
This reduces the potential for problems in the future if equipment
changes are made. Connector pinouts are provided in Chapter 2,
Installation Requirements/Specifications.
All four HUBs incorporate Cabletron Systems’ LANVIEW™ status
monitoring and diagnostic system. LANVIEW is a convenient
troubleshooting tool that allows you to monitor power, and data
activity and help you diagnose power failures, collisions, cable faults,
and link problems.
The MRXI provides an RS-232 Console port (not available in the
MRX) that supports a Digital Equipment Corporation™, VT220™ or
PC emulation of the VT220™ terminal. The terminal serves as a
local management console, providing out-of-band access to MRXI/
LM™, Local Management for the Cabletron Systems MRXI/MRXI-2.
MRXI/LM is an effective menu driven tool that presents screens that
integrate network status and network control. Several menus permit
the network manager to manage and monitor the flow of traffic and
access a summary of errors to pinpoint potential problem areas in a
network. This capability gives the network manager the ability to
interpret status and establish parameters to obtain optimal
performance for the network and, if necessary, permit diagnosis of
network problems. For additional information, refer to the
MRXI/LM, Local Management for the Cabletron Systems
MRXI/MRXI-2, User’s Manual.