13.1 Concepts of Optical Networks
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Data Packet (or Simply Packet) A data packet is a group of information bits plus
overhead bits for transportation management of the data.
Stations Devices that network subscribers use to communicate are called stations.
These may be computers, monitoring equipment, telephones, fax machines, or other
telecom equipment.
Networks To establish connections between these stations, transmission paths run
between them to form a collection of interconnected stations called a network.
Node Within this network, a node is a point where one or more communication
lines terminate and/or where stations are connected. Stations also can be connected
directly to a transmission line.
Server A network server is a powerful computer that provides users with access to
shared software or hardware resources. The shared resources can include disk space,
hardware access, and email services. A server typically has a large amount of random
access memory (RAM) and runs continuously on a robust operating system.
Trunk The term trunk normally refers to a transmission line that runs between nodes
or networks and supports large traffic loads.
Topology The topology is the logical manner in which nodes are linked together by
transmitting channels to form a network.
Switching and Routing The transfer of information from source to destination is
achieved through a series of switches residing at intermediate nodes and the process is
called switching. The selection of a suitable path through a network is accomplished
by means of routers and the process is referred to as routing.
Thus a switched communication network consists of an interconnected collection
of nodes, in which information streams that enter the network from a station are
routed to the destination by being switched from one transmission path to another at
a node.
13.1.2 Generic Network Categories
Networks can be divided into several broad generic categories, as Fig. 13.2 illustrates.
Note that there is nothing unique about this illustration, because it merely shows
general interconnection hierarchies. The following definitions are useful to know:
Local Area Network (LAN) A local area network (LAN) interconnects users in a
localized area such as a large room or work area, a department, a home, a building, an
office or factory complex, or a small group of buildings. A LAN employs relatively
inexpensive hardware that allows users to share common expensive resources such
as servers, high-performance printers, specialized instrumentation, or other equipment. Ethernet is the most popular networking technology used in LANs. Local area
networks usually are owned, used, and operated privately by a single organization.
509
Data Packet (or Simply Packet) A data packet is a group of information bits plus
overhead bits for transportation management of the data.
Stations Devices that network subscribers use to communicate are called stations.
These may be computers, monitoring equipment, telephones, fax machines, or other
telecom equipment.
Networks To establish connections between these stations, transmission paths run
between them to form a collection of interconnected stations called a network.
Node Within this network, a node is a point where one or more communication
lines terminate and/or where stations are connected. Stations also can be connected
directly to a transmission line.
Server A network server is a powerful computer that provides users with access to
shared software or hardware resources. The shared resources can include disk space,
hardware access, and email services. A server typically has a large amount of random
access memory (RAM) and runs continuously on a robust operating system.
Trunk The term trunk normally refers to a transmission line that runs between nodes
or networks and supports large traffic loads.
Topology The topology is the logical manner in which nodes are linked together by
transmitting channels to form a network.
Switching and Routing The transfer of information from source to destination is
achieved through a series of switches residing at intermediate nodes and the process is
called switching. The selection of a suitable path through a network is accomplished
by means of routers and the process is referred to as routing.
Thus a switched communication network consists of an interconnected collection
of nodes, in which information streams that enter the network from a station are
routed to the destination by being switched from one transmission path to another at
a node.
13.1.2 Generic Network Categories
Networks can be divided into several broad generic categories, as Fig. 13.2 illustrates.
Note that there is nothing unique about this illustration, because it merely shows
general interconnection hierarchies. The following definitions are useful to know:
Local Area Network (LAN) A local area network (LAN) interconnects users in a
localized area such as a large room or work area, a department, a home, a building, an
office or factory complex, or a small group of buildings. A LAN employs relatively
inexpensive hardware that allows users to share common expensive resources such
as servers, high-performance printers, specialized instrumentation, or other equipment. Ethernet is the most popular networking technology used in LANs. Local area
networks usually are owned, used, and operated privately by a single organization.