Glossary
ageing: The automatic removal of dynamic entries from the Switch Database which have
ATM: Asynchronous Transfer Mode. A connection oriented transmission protocol based on fixed length cells (packets). ATM is designed to carry a complete range of user traffic, including voice, data and video signals.
backbone: The part of a network used as the primary path for transporting traffic between network segments.
bandwidth: Information capacity, measured in bits per second, that a channel can transmit. The bandwidth of Ethernet is 10Mbps, the bandwidth of Fast Ethernet is 100Mbps.
baud rate: The switching speed of a line. Also known as line speed between network segments.
BOOTP: The BOOTP protocol allows you to automatically map an IP address to a given MAC address each time a device is started. In addition, the protocol can assign the subnet mask and default gateway to a device.
bridge: A device that interconnects local or remote networks no matter what higher level protocols are involved. Bridges form a single logical network, centralizing network administration.
broadcast: A message sent to all destination devices on the network.
broadcast storm: Multiple simultaneous broadcasts that typically absorb available network bandwidth and can cause network failure.
console port: The port on the Switch accepting a terminal or modem connector. It changes the parallel arrangement of data within computers to the serial form used on data transmission links. This port is most often used for dedicated local management.
CSMA/CD: Channel access method used by Ethernet and IEEE 802.3 standards 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 amount of time.
data center switching: The point of aggregation within a corporate network where a switch provides
Ethernet: A LAN specification developed jointly by Xerox, Intel and Digital Equipment Corporation. Ethernet networks operate at 10Mbps using CSMA/CD to run over cabling.
Fast Ethernet: 100Mbps technology based on the Ethernet/CD network access method.
Flow Control: (IEEE 802.3z) A means of holding packets back at the transmit port of the connected end station. Prevents packet loss at a congested switch port.
forwarding: The process of sending a packet toward its destination by an internetworking device.
full duplex: A system that allows packets to be transmitted and received at the same time and, in effect, doubles the potential throughput of a link.
half duplex: A system that allows packets to be transmitted and received, but not at the same time. Contrast with full duplex.
IP address: Internet Protocol address. A unique identifier for a device attached to a network using TCP/IP. The address is written as four octets separated with
IPX: Internetwork Packet Exchange. A protocol allowing communication in a NetWare network.
LAN - Local Area Network: A network of connected computing resources (such as PCs, printers, servers) covering a relatively small geographic area (usually not larger than a floor or building). Characterized by high data rates and low error rates.
latency: The delay between the time a device receives a packet and the time the packet is forwarded out of the destination port.
line speed: See baud rate.
main port: The port in a resilient link that carries data traffic in normal operating conditions.
MDI - Medium Dependent Interface: An Ethernet port connection where the transmitter of one device is connected to the receiver of another device.
MIB - Management Information Base: Stores a device's management characteristics and parameters. MIBs are used by the Simple Network Management Protocol (SNMP) to contain attributes of their managed systems. The Switch contains its own internal MIB.
multicast: Single packets copied to a specific subset of network addresses. These addresses are specified in the destination- address field of the packet.
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