Glossary

: The IEEE 802.3 physical layer specification for a 10 Mbps Ethernet network over two pairs of Category 3, 4, or 5 UTP wire.

: The IEEE 802.3 physical layer specification for a 100 Mbps Ethernet network over two strands of fiber.

: The group of IEEE 802.3 physical layer specifications for a 100 Mbps Ethernet network over various wiring specifications.

: The IEEE 802.3 physical layer specification for a 100 Mbps Ethernet network over four pairs of Category 3, 4, or 5 UTP wire.

: The IEEE 802.3 physical layer specification for a 100 Mbps Ethernet network over two pairs of Category 5 UTP or STP wire.

Advanced RPS

: 3Com SuperStack II Advanced Redundant Power System.

: The main transmission medium used to interconnect the workgroup areas of a network. Fiber-optic cable is often used for the backbone connection.

: A device that interconnects local or remote networks no matter what higher-level protocols (such as XNS or TCP/IP) are involved. Bridges form a single logical network, centralizing network administration. They operate at the physical and link layers of the Open Systems Interconnection (OSI) reference model.

: Category 3 balanced cable. Balanced 100 and 120 cables and associated connecting hardware whose transmission characteristics are specified up to 16 MHz. Used by 10BASE-T and 100BASE-T4 installations.

: Category 4 balanced cable. Balanced 100 and 120 cables and associated connecting hardware whose transmission characteristics are specified up to 20 MHz. Used by 10BASE-T and 100BASE-T4 installations.

: Category 5 balanced cable. Balanced 100 and 120 cables and associated connecting hardware whose transmission characteristics are specified up to 100 MHz. Used by 10BASE-T and 100BASE-T installations.

: Copper Distributed Data Interface. FDDI over twisted-pair copper wire. See also FDDI.

: A type of 100BASE-T repeater with internal delay such that only one repeater or stack can exist between any two end stations within a single collision domain when two maximum-length copper cable segments are used.

: A type of 100BASE-T repeater with internal delay such that two repeaters or stacks can exist between any two end stations within a single collision domain when two maximum-length copper cable segments are used.

: A condition that results from concurrent transmissions from multiple sources within a single collision domain.

collision domain

: A single CSMA/CD network. If two or more Media Access Control (MAC) sublayers are within the same collision domain and both transmit at the same time, a collision will occur. MAC sublayers separated by a repeater are in the same collision domain; MAC sublayers separated by a bridge, router, or switch are within different collision domains.

crossover cable

: A patch cable wired to route the receive signals from one device to the transmit signals of another device, and vice versa.

: Carrier Sense Multiple Access/Collision Detection. Channel access method used by Ethernet and IEEE 802.3 in which devices transmit only after finding the data channel clear for some period of time. When two devices transmit simultaneously, a collision occurs and the colliding devices delay their retransmissions for a random length of time.

: Data terminal equipment. End-user equipment, typically a terminal or computer, that can function as the source or destination point of communication on the network.

: Electronic Industries Association/Telecommunications Industries Association.

: A local area network standard defining a physical medium and its method of placing data, or packet signaling, on a cable. Access to the cable is based on CSMA/CD (Carrier Sense Multiple Access/Collision Detection).

Fast Ethernet

: A 100 Mbps technology based on the Ethernet CSMA/CD network access method.

: Fiber Distributed Data Interface. The local area networking standard that provides high bandwidth for interconnecting computers and peripheral devices using a fiber-optic medium in a ring configuration.
: The FDDI specification is made up of standards that correspond to the IEEE OSI model layers (on the physical and data link levels). These standards specify the physical interfaces, functions, and operations needed to support interoperability between devices.

fiber-optic cable

: Cable consisting of a glass center, cladding, a buffer layer, strength members, and a cable sheath. The glass center supports the transmission of light signals.

: Flexible Media Stack. 3Com family of stackable hubs.

: A device used to provide connectivity between network devices. Hubs perform the basic repeater functions of restoring signal amplitude and timing, detecting collisions, and broadcasting signals to network devices. See also repeater.

: Institute of Electrical and Electronics Engineers. Committees that develop and propose computer standards, such as the 802 protocols, which define the physical and data link protocols of communication networks. Members represent an international cross section of users, vendors, and engineering professionals.

: Local area network. An assembly of computing resources such as PCs, printers, minicomputers, and mainframe computers linked by a common transmission medium such as UTP.

: Light-emitting diode. A diode that converts voltage to light and that is commonly used in digital displays.

: Media Access Control. The data link sublayer that is responsible for transferring data to and from the physical layer.

: Megabits per second.

: Management Information Base. A logical naming of all information resources residing in a network and pertinent to the network's management. Simple Network Management Protocol (SNMP) management uses a set of standard MIBs known as MIB II and other standard MIBs for FDDI, Ethernet, etc. In addition, vendors write proprietary MIB extensions for SNMP management of particular devices.

: A repeater function that isolates a particular port from the network because of an excessive number of collisions. Once the problem causing the collisions is corrected, the port is reactivated.

: A device that extends the length, topology, or interconnectivity of the physical medium beyond that imposed by a single segment, up to the maximum allowable end-to-end trunk transmission line length. Repeaters perform the basic actions of restoring signal amplitude, waveform, and timing applied to normal data and collision signals. See also Hub.

: Protocol-dependent device that connects subnetworks together. It is useful in breaking down a very large network into smaller subnetworks. Routers introduce longer delays and typically have much lower throughput rates than bridges. See also bridge.

: A fiber-optic cable connector used in the 100BASE-FX Fast Ethernet fiber-optic media system. When it is pushed into place, the connector is seated automatically.

: Simple Network Management Protocol. A network monitoring protocol for TCP/IP-based networks. It is a simple request/response protocol used to communicate management information between the network management station and the agent residing in network elements. The protocol does not define the objects that can be managed. (The MIB defines manageable objects.) SNMP can be used with any network management variable that can be inspected and altered.

: Shielded twisted-pair. Shielded four-conductor electrical cable that offers high-speed transmission for long distances.

: 3Com system of stackable hubs, servers, switches, routers, SDLC converters, and power supplies. SuperStack systems can support a range of LAN environments, including Ethernet, token ring, FDDI, SNA, and ATM.

transceiver

: A hardware device that links a node to a network cable and functions as both a transmitter and a receiver.

twisted-pair

: Wiring similar to that found in the telephone system, consisting of two insulated wires loosely twisted around each other to help cancel out induced noise in balanced circuits.

: Unshielded twisted-pair. A cable consisting of two or more pairs of twisted copper wires that are not shielded.

[previous]

[next]