Cabletron Systems NB20E - Manual (Page 8)

INTRODUCTION
1-2
1.2 GETTING HELP
If you need additional support related to the Cabletron Systems NB20E or
NB25E Two Port Ethernet Bridge, or if you have any questions,
comments or suggestions related to this manual, feel free to contact
Cabletron Systems' Technical Support at:
Cabletron Systems Inc.
P.O. Box 6257
E. Rochester, NH 03867-6257
Phone: (603) 332-9400
1.3 THE NB20E AND NB25E TWO PORT ETHERNET
BRIDGE
With the Cabletron Systems NB20E or NB25E Two Port Ethernet Bridge,
you can dramatically increase the performance of two 10 Mbit per second
Ethernet networks efficiently and economically, regardless of the media
type. The bridges are designed to increase the efficiency of bandwidth use
across a LAN by building a list of local node addresses as it learns which
nodes are located on each side of the bridge. This list is called the Source
Address Table. The bridge uses the Source Address Table to determine
which data packets should be allowed to cross the bridge, keeping local
traffic local.
The NB20E Bridge uses a software filter database to check destination
addresses against its Source Address Table. The NB25E Bridge uses a
higher performance hardware filter database. Both bridges are equipped
with a feature called Aging Time, that continually makes space for new
entries into the Source Address Table by deleting addresses that are not
frequently used.
The NB20E and NB25E are designed to function in multiple-bridge
environment. As IEEE 802.1 compliant bridging units, the bridges
incorporate a Spanning Tree Algorithm to detect potential data loops in
the network. Spanning Tree Algorithm is a hierarchy (or tree) of priorities
that is established between bridges.
The NB20E and NB25E can be controlled and managed by Cabletron
Systems' Remote LANVIEW™ - Network Control Management for the
Cabletron Systems' NB20E and NB25E. Remote LANVIEW provides the
most complete network management system for Ethernet networks in the
industry today. With Remote LANVIEW, a bridge can be managed