3Com 4005, Installation And Maintenance Manual

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LOSSARY
CSMA/CD Carrier Sense Multiple Access with Collision Detection. This is the way that
Ethernet works. Ethernet nodes listen for transmissions by other nodes, then
transmit when they believe it is quiet. Collisions are possible. If nodes detect that
their transmission has collided with another transmission, both back off and begin
the process again. This all occurs in milliseconds.
enterprise network A large network that connects most major points in a company. Differs from a
WAN in that it is typically private and contained within a single organization.
Ethernet A CSMA/CD, 10 Mbps, local area data network technology, developed by Digital
Equipment Corporation, Xerox Corporation, and Intel. It and its derivatives, Fast
Ethernet and Gigabit Ethernet, are the most popular baseband LAN technologies
in use today. A written standard is available from the IEEE.
Fast Ethernet A 100 Mbps local area data network technology that was developed a few years
after Ethernet to meet increased bandwidth requirements from customers. To give
customers flexibility, equipment vendors like 3Com often design ports to support
either 10 Mbps or 100 Mbps Ethernet connections. A written standard is available
from the IEEE.
fault-tolerant The ability to prevent a device or network from failing by supplying a backup
component or link to take over in case of failure. For example, the reserve power
of an extra power supply in a single device can prevent the device from failing if
the primary power supply fails. Another example could be an extra link in a
network that is inactive until the primary link fails or reaches capacity.
Gigabit Ethernet A 1000 Mbps local area data network technology that was developed a few years
after Fast Ethernet. It is compatible with existing 10/100 Ethernet standards.
The IEEE, with the help of the Gigabit Ethernet Alliance, defines the standard for
full duplex over fiber-optic cable and short-haul copper cable.
hot swapping A feature that allows specified components to be removed and replaced while the
device is powered up and continues to operate normally.
IEEE 802.3 The IEEE LAN protocol standard that specifies an implementation of the physical
layer and the MAC sublayer of the data link layer. IEEE 802.3 uses CSMA/CD
access at a variety of speeds over a variety of physical media. Extensions to the
IEEE 802.3 standard specify implementations for Fast Ethernet and Gigabit
Ethernet.
IGMP Internet Group Management Protocol. A multicast protocol that operates between
routers or switches and their attached hosts to allow a host to inform its local
router or switch that it wants to receive transmissions addressed to a specific
multicast group. Based on group membership information that is learns from
IGMP, a router can determine which, if any, multicast traffic needs to be forwarded
to each of its “leaf” subnetworks.
in-band Transmission of information (for example, device management commands or
requests) over the same network media that carries user traffic. Contrasts with
out-of-band .
Internet Protocol (IP) The protocol that governs packet forwarding within the Transmission Control
Protocol/Internet Protocol (TCP/IP) suite of standards that was developed for and is
used on the Internet and in local area networks.