"networking 101: basics" jim gogan inls184. introduction - why network? l communicate with...
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"Networking 101: Basics""Networking 101: Basics"
Jim Gogan
INLS184
Introduction - Why network?Introduction - Why network?
Communicate with others close by Communicate with others far away Gain access to information not on your
computer Share resources (software, peripherals)
*ANS?*ANS?
LANs WANs MANs internets Internet Intranet
Components of a LANComponents of a LAN
Cable Workstations/Servers Interface cards (NICs) Hubs/switches/etc. Peripherals Network protocols
CableCable
Types of Cables– Coaxial cable– Twisted pair– Fiber optics
Wireless
Cabling Topologies Cabling Topologies
Daisy Chain Bus Ring Star
Daisy Chain Daisy Chain
Simplest to do One device hooked to device after it If broken, all connections are lost Daisy Chain network example: original
LocalTalk
BusBus
Packets move along a straight line Works like a trolley, must have bumpers at
ends of lines Devices are connected through taps on the
line As long as taps aren’t disconnected, network
stays up Bus network example: Thin-net Ethernet
RingRing
Cable must form complete, unbroken ring Packets with presence of token (usually) If ring broken, all devices may go down Ring network example: Token Ring
StarStar
Devices are connected along “arms” of the star
Arms connected to central hub When disconnected, only that arm of the
star is affected Star network example: 10BaseT Ethernet
WorkstationsWorkstations
The computer on an individual’s desk May have its own local devices/peripherals
as well as access to networked peripherals
ServersServers
Workstation (often higher end) with specific functions
Usually provides services:– File services– Web services– Email services
Interface cardsInterface cards
Connect individual devices to network Must match type of device and type of
cable
Hubs and Switches and Hubs and Switches and Network DevicesNetwork Devices
Depends on type of network installed More about these later …...
PeripheralsPeripherals
Accessory devices (printers, fax machines, backup devices, etc.)
Originally connected thru workstations or servers, now directly network connected
Originally dumb, now intelligent enough to do some real damage
ProtocolsProtocols
Common language among computers Analogous to addressing envelopes Many different protocols out there Different “layers” use different protocols
Network AddressingNetwork Addressing
Must be unique to each device A single physical device can have several
network addresses Usually divided into two parts: network and
node (both parts can be combined into one address)
May be permanent (static) or temporary (dynamic)
PacketsPackets
Way information moves across the wire Packets can carry data or protocol/control
information only Difference between “packet” and “cell”
How Networks GrowHow Networks Grow File sharing Application sharing Peripheral sharing Client/server applications
– Email– WWW
Multimedia applications
Dividing/Expanding NetworksDividing/Expanding Networks
Why:– Too much traffic– Too many nodes– Distance limitations
How:– Repeaters– Bridges– Routers
Performance TermsPerformance Terms
Bandwidth Throughput Latency (delay) Jitter Loss
Other Aspects/ConsiderationsOther Aspects/Considerations
Security Management
Key PointsKey Points
Standards = Good! Simplicity = Good! (easy to develop) Ethernet = Good! (it’s simple) TCP/IP = Good! (it’s simple)