3com 7600 Benutzerhandbuch
11
E
THERNET
LAN
S
AND
B
RIDGES
IN
THE
7600 C
ARD
This chapter provides basic concepts and information about the following
topics and how they are implemented in the 7600 Card.
topics and how they are implemented in the 7600 Card.
Q
Overview of Ethernet
Q
Fast Ethernet
Q
Transparent Bridges
Q
Spanning Tree Protocol
Q
Bridged-LAN Environments and vLANs
Overview of
Ethernet
Ethernet
An Ethernet is a CSMA/CD (Carrier Sense, Multiple Access with Collision
Detection) LAN. Carrier Sense means that a device on an Ethernet senses
the traffic and transmits only when the medium is idle. Multiple Access
means that many devices share the same medium and have equal access
rights to transmit. Collision Detection means that devices monitor the
medium even while they are transmitting and so can detect a collision,
that is, another station transmitting while they are transmitting.
Detection) LAN. Carrier Sense means that a device on an Ethernet senses
the traffic and transmits only when the medium is idle. Multiple Access
means that many devices share the same medium and have equal access
rights to transmit. Collision Detection means that devices monitor the
medium even while they are transmitting and so can detect a collision,
that is, another station transmitting while they are transmitting.
The speed of transmission on an Ethernet LAN is normally 10 Mbps.
Stations on an Ethernet LAN can include computers, workstations or
terminals. Ethernet LANs use a common bus that consists of a coax,
twisted pair or fiber-optic cable that runs between the stations. The
connection point of each station to the cable is called a node. Two or
more LANs can be connected together by a bridge to form an efficient
bridged-LAN environment. In this context, an Ethernet LAN is also called
an Ethernet segment.
terminals. Ethernet LANs use a common bus that consists of a coax,
twisted pair or fiber-optic cable that runs between the stations. The
connection point of each station to the cable is called a node. Two or
more LANs can be connected together by a bridge to form an efficient
bridged-LAN environment. In this context, an Ethernet LAN is also called
an Ethernet segment.
abtthgde.book Page 1 Tuesday, June 23, 1998 10:29 AM