Networking Fundamentals
Introduction and OSI model
OSI Model
A Layered Approach To Manage Complexity
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Application Layer
Presentation Layer
Session Layer
Transport Layer
Network Layer
Data Link Layer
Physical Layer
Introduction
CLASSIFICATIONS
Classifications
• LAN
– Local Area Network
• WAN
– Wide Area Network
• PAN
– Personal Area Network
• MAN
– Metropolitan Area Network
Introduction
TOPOLOGIES
Topologies
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Bus
Star
Ring
Mesh
Wireless
Hybrid
Introduction
NETWORK MODELS
Network Models
• Client/Server
• Peer-to-Peer
Introduction
PROTOCOLS
Protocols
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TCP/IP
FIR
ATM
LLDP
NetBIOS & NetBEUI
HTTP
FTP
SMTP
Introduction
DEVICES
Devices
• Media / Converters
• NIC
– Network Interface Card
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Repeater
Hub
Gateway
Bridge
Switch
Router
Hub
• Physical Layer
• Box with lots of Ethernet connection sockets
• Repeats messages to all connected nodes
– Generates wasted traffic
– Nodes must filter messages intended
for them
• Cheapest way
to connect
devices
Bridge
• Data Link Layer
• Single incoming and outgoing ports
• Keeps MAC address tables for two LAN
segments
• Filters traffic using the MAC address
Switch
• Connects all nodes to each other like a hub
• Examines Ethernet messages for destination
MAC address
• Intelligently relays messages toward
destination
• More expensive than hubs
• Can be combined with hubs
Router
• Network Layer
• A router connects to two different networks
Ex: LAN to WAN (internet)
• Routers maintain a so-called routing table to
keep track of routes
– Without routers the internet could not function
– Uses the IP address to forward packets
Gateway
• Application Layer down to network layer
• Connect and translate data between networks
with different protocols or architecture
• For instance, allowing communication between
TCP/IP clients and IPX/SPX or AppleTalk
• A gateway links two systems that do not use the
same:
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Communication protocols
Data formatting structures
Languages
Architecture
Introduction
STANDARDS GROUPS
Standards Groups
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IEEE
ISO
W3C
CERN
UL
EIA
TIA
ANSI
Standards Groups
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IEEE
Institute of Electrical and Electronics Engineers
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ISO
International Organization for Standardization
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W3C
World Wide Web Consortium
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CERN
European Organization for Nuclear Research
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UL
Underwriters Laboratories
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EIA
Energy Information Administration
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TIA
Telecommunications Industry Association
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ANSI
American National Standards Institute
Introduction
OSI MODEL
OSI MODEL
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Application
Presentation
Session
Transport
Network
Data Link
Physical
Mnemonics to Remember
Top Down:
A Perfectly Simple Technology Narrowed Down Physically
All People Seem To Need Data Processing
All Pros Search Top Notch Donut Places
Bottom Up:
Programmers Like Networks That Seldom Postpone Anything*
Programmers Dare Not Throw Salty Pretzels Away
Please Do Not Throw Sausage Pizza Away
Please Do Not Tell Sales People Anything
People Don’t Need To See Paula Abdul
People Desperately Need To See Pamela Anderson
Paula Did Networking 'Til She Passed Away
* Uses L for Link layer rather than D for Data Link