Networks

Network ClassificationsAcronyms, acronyms, and more acronyms

• What does PAN stand for?– Personal Area Network – interconnection of

personal digital devices• typically involve a mobile computer, cell phone, and/or

a handheld computing device• might be connected via USB or FireWire or bluetooth

PAN

Network ClassificationsAcronyms, acronyms, and more acronyms

• What does LAN stand for?– Local Area Network – usually connects computers

in a single building• examples: a networked office building or a school

LAN

Network ClassificationsAcronyms, acronyms, and more acronyms

• What does MAN stand for?– Metropolitan Area Network – public high-speed

network with range of about 50 miles• typically owned/operated by a single entity such as a

government body or large corporation

MAN

Network ClassificationsAcronyms, acronyms, and more acronyms

• What does NAN stand for?– Neighborhood Area Network – connectivity

spread over several buildings• service area smaller than metropolitan, larger than

local area networks

Network ClassificationsAcronyms, acronyms, and more acronyms

• What does WAN stand for?– Wide Area Network – consists of several smaller

networks• example: internet• generally not owned by a single organization, but

instead exist under collective or distributed ownership/management

WAN

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LAN Standards LAN technologies are standardized by the Institute of

Electrical and Electronics Engineers (IEEE) Project 802 – Local Network Standards– IEEE 802.3– Ethernet

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Network Devices Each connection point on a network is referred to as a node

To connect to a LAN, a computer requires network circuitry, sometimes referred to as a network interface card (NIC)

A networked peripheral, or network-enabled peripheral, is any device that contains network circuitry to directly connect to a network

A network device, or network appliance, is any electronic device that broadcasts network data, boosts signals, or routes data to its destination

Chapter 5: LANs and WLANs 13

NICIntel EXPI9301CTBLK 10/ 100/ 1000Mbps PCI-Express

Network Adapter 1 x RJ45

NICVisionTek Bigfoot Killer 2100 Gaming Network Card

Killer™ 2100 is up to 10x faster than other NICs

5 Network Devices

Chapter 5: LANs and WLANs 15

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Chapter 5: LANs and WLANs 16

Clients, Servers, and Peers Network devices can function as clients or as servers

– Application server– File server– Print server

Networks that include one or more servers can operate in client/server mode

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Physical Topology The arrangement of devices in a network is referred to as its physical

topology– Star– Ring– Bus– Mesh– Tree

Two similar networks can be connected by a device called a bridge

Gateway is a generic term for any device or software code used to join two networks

Star Topology

One of the most common topologies

Advantages:

-prevents the passing of data packets through an excessive number of nodes

-as the central hub is the bottleneck, increasing its capacity, or connecting additional devices to it, increases the size of the network very easily

-easy to understand

Star Topology

Disadvantages:

-High dependence of the system on the functioning of the central hub

-Failure of the central hub renders the network inoperable

-Network size is limited by the number of connections that can be made to the hub

Ring Topology

Topology in which each node connects to exactly two other nodes

Advantage:

-Generally performs better than a bus topology under heavy network load

Ring Topology

Disadvantages:

-One malfunctioning workstation can create problems for the entire network

-Moves, adds and changes of devices can affect the network

Bus Topology

Topology in which a set of clients are connected via a shared communication line

Advantages:

-Easy to implement

-Cheaper than other topologies

-Well-suited for temporary or small networks not requiring high speeds

Bus Topology

Disadvantages:

-If there is a problem with the cable the entire network breaks down

-Performance degrades as additional computers are added or on heavy traffic

-Commonly has a slower data transfer rate than other topologies

Mesh Topology

Topology in which each computer and network devices are interconnected

Advantage:

-Possible to transmit data from one node to many other nodes at the same time

Mesh Topology

Disadvantage:

-Redundant connections can be expensive

Tree Topology

Also known as a hierarchical network

Advantage:

-Point-to-point wiring for individual segments

Tree Topology

Disadvantage:

-More difficult to configure and wire than other topologies

How have networks changed our lives?

For better?

For worse?

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Chapter 5: LANs and WLANs 29

LAN Advantages LANs enable people to work together

Sharing networked software can reduce costs

Sharing data on a LAN can increase productivity

Sharing networked hardware can reduce costs

Sharing networked hardware can provide access to a wide range of services and specialized peripheral devices

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LAN Challenges Resources become unavailable when network malfunctions

Networks may be vulnerable to unauthorized access– More vulnerable than standalone computers

Wireless networks can be tapped from a “snooping” computer

Networked computers are susceptible to an increasing number of worms, Trojan horses, and blended threats

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Chapter 5: LANs and WLANs 31

LAN Parties A LAN party is a gathering

of people who connect their own computers to a LAN, usually to play multiplayer computer games– No special hardware

usually is required– Game must have

multiplayer capability

Name that topology!

Tree

Name that topology!

Ring

Name that topology!

Bus

Name that topology!

Mesh

Name that topology!

Star

What does MAN stand for?

Metropolitan Area Network

What does NAN stand for?

Neighborhood Area Network

What does LAN stand for?

Local Area Network

What does WAN stand for?

Wide Area Network

What does PAN stand for?

Personal Area Network