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Glossary

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topology using a unidirectional closed-loop star rather than point-to-point
links. That is, connections within the hub are arranged in an internal ring.
See also: bus topology and ring topology.

startup range

If an AppleTalk node does not have a number saved from

the last time it was booted, then the node selects from the range of values
from 65,280 to 65,534.

state transitions

Digital signaling scheme that reads the "state" of the

digital signal in the middle of the bit cell. If it is five volts, the cell is read as
a one. If the state of the digital signal is zero volts, the bit cell is read as a zero.

static route

A route whose information is purposefully entered into the

routing table and takes priority over those chosen by dynamic routing
protocols.

static VLAN

A VLAN that is manually configured port-by-port. This is

the method typically used in production networks.

statistical multiplexing

Multiplexing in general is a technique that allows

data from multiple logical channels to be sent across a single physical
channel. Statistical multiplexing dynamically assigns bandwidth only to
input channels that are active, optimizing available bandwidth so that more
devices can be connected than with other multiplexing techniques. Also
known as statistical time-division multiplexing or stat mux.

STM-1

Synchronous Transport Module Level 1. In the European SDH

standard, one of many formats identifying the frame structure for the
155.52Mbps lines that are used to carry ATM cells.

store-and-forward packet switching

A technique in which the switch

first copies each packet into its buffer and performs a cyclical redundancy
check (CRC). If the packet is error-free, the switch then looks up the desti-
nation address in its filter table, determines the appropriate exit port, and
sends the packet.

STP

1) shielded twisted-pair: A two-pair wiring scheme, used in many net-

work implementations, that has a layer of shielded insulation to reduce EMI.
2) Spanning Tree Protocol.

straight-through cable

Type of Ethernet cable that connects a host to a

switch, host to a hub, or router to a switch or hub.

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