This document provides an introduction to networking, including definitions of basic networking concepts and components. It defines what a computer network is and discusses reasons for networking. It also describes different types of networks including LANs and WANs, transmission media like twisted pair, coaxial, and fiber optic cables. Additionally, it covers topics like network topologies, peer-to-peer vs. client-server networks, and network devices.
01 elements of modern networking by nader elmansiNader Elmansi
Foundations of Modern Networking SDN, NFV, QoE, IoT, and Cloud
PART I MODERN NETWORKING
CHAPTER 1 Elements of Modern Networking
regenerated by Nader Elmansi
01 elements of modern networking by nader elmansiNader Elmansi
Foundations of Modern Networking SDN, NFV, QoE, IoT, and Cloud
PART I MODERN NETWORKING
CHAPTER 1 Elements of Modern Networking
regenerated by Nader Elmansi
The sole purpose to study Enterprise Network is to create business simplicity across worldwide. The side arms of successful networking are scalability, robustness, fault identification, communication, modularity, security and maintaining privacy. The key for making a network is to provide the essential tools and techniques that will offer the quality of a private/public network.
As I discussed earlier the key purpose is to create business simplicity that means creating IT/Infrastructure simplicity across the cities where an Enterprise Network is connected. Obtaining success in failure/break-down conditions is the main purpose of a network. So to achieve that requirement network designing involves certain topologies, protocols, bandwidth allocation. Topology requirement can be described as maintaining two adjacent networks against any failure in a single link or node. Protocol requirement can be described as using dynamic/static routing protocol to provide routes must be congestion free in a network. Bandwidth allocation is needed to actively allocate extra bandwidth just to maintain the working condition in a network. Design and Modification criteria is all over handed to a person called Network Administrator, who maintains and solely responsible for anything(wanted or unwanted) happens in a network.
A lecture slide on the the introduction to microprocessors and microcomputers as outlined from the book Microprocessors and MIcrocomputers by John Uffenbeck
Practical Troubleshooting and Problem Solving of Ethernet NetworksLiving Online
While the basic structure of Ethernet has not changed much, the faster technologies such as Fast Ethernet and Gigabit Ethernet have increased the complexity and choices you have available in planning and designing these systems. As Ethernet has become more complex, a number of misconceptions have arisen as to how Ethernet functions and how the system should be optimally configured. This manual addresses these issues in a clear and practical manner, thus enabling you to apply the technology quickly and effectively in your next project. This manual commences with a brief outline of the Fundamentals of Ethernet and its operation.
The method of access is discussed in depth, and topics such as full duplex and auto negotiation are explained. The best methods of designing and installing the cabling systems are then explored with the discussion ranging from 10Base-T over twisted pair to Gigabit Ethernet cabling. Methods of optimising Ethernet to obtain best performance are then defined. Finally the all important topic of troubleshooting is examined with a summary of the typical problems you are likely to encounter from a two station network all the way up to a system comprising 30,000 PCs.
MORE INFORMATION: http://www.idc-online.com/content/practical-troubleshooting-problem-solving-ethernet-networks-26?id=48
This presentation contains Networking Basics Concepts and basic topologies of Computer Networking discussed. Also gives information about Cisco History.
These slides discuss the basics of network security.
The first question that should be answered is, why is network security important?
Understanding the increasing threats to security from the past to today.
How to think like an attacker?
Step 1. Perform footprint analysis (reconnaissance).
Step 2. Enumerate information.
Step 3. Manipulate users to gain access.
Step 4. Escalate privileges.
Step 5. Gather additional passwords and secrets.
Step 6. Install backdoors.
Step 7. Leverage the compromised system.
The trade off between open versus closed networks.
Developing a security policy for the company or organization is a must.
Understanding the common security threats and the different types of network attacks.
Finally, general mitigation techniques and the security appliances and applications
The sole purpose to study Enterprise Network is to create business simplicity across worldwide. The side arms of successful networking are scalability, robustness, fault identification, communication, modularity, security and maintaining privacy. The key for making a network is to provide the essential tools and techniques that will offer the quality of a private/public network.
As I discussed earlier the key purpose is to create business simplicity that means creating IT/Infrastructure simplicity across the cities where an Enterprise Network is connected. Obtaining success in failure/break-down conditions is the main purpose of a network. So to achieve that requirement network designing involves certain topologies, protocols, bandwidth allocation. Topology requirement can be described as maintaining two adjacent networks against any failure in a single link or node. Protocol requirement can be described as using dynamic/static routing protocol to provide routes must be congestion free in a network. Bandwidth allocation is needed to actively allocate extra bandwidth just to maintain the working condition in a network. Design and Modification criteria is all over handed to a person called Network Administrator, who maintains and solely responsible for anything(wanted or unwanted) happens in a network.
A lecture slide on the the introduction to microprocessors and microcomputers as outlined from the book Microprocessors and MIcrocomputers by John Uffenbeck
Practical Troubleshooting and Problem Solving of Ethernet NetworksLiving Online
While the basic structure of Ethernet has not changed much, the faster technologies such as Fast Ethernet and Gigabit Ethernet have increased the complexity and choices you have available in planning and designing these systems. As Ethernet has become more complex, a number of misconceptions have arisen as to how Ethernet functions and how the system should be optimally configured. This manual addresses these issues in a clear and practical manner, thus enabling you to apply the technology quickly and effectively in your next project. This manual commences with a brief outline of the Fundamentals of Ethernet and its operation.
The method of access is discussed in depth, and topics such as full duplex and auto negotiation are explained. The best methods of designing and installing the cabling systems are then explored with the discussion ranging from 10Base-T over twisted pair to Gigabit Ethernet cabling. Methods of optimising Ethernet to obtain best performance are then defined. Finally the all important topic of troubleshooting is examined with a summary of the typical problems you are likely to encounter from a two station network all the way up to a system comprising 30,000 PCs.
MORE INFORMATION: http://www.idc-online.com/content/practical-troubleshooting-problem-solving-ethernet-networks-26?id=48
This presentation contains Networking Basics Concepts and basic topologies of Computer Networking discussed. Also gives information about Cisco History.
These slides discuss the basics of network security.
The first question that should be answered is, why is network security important?
Understanding the increasing threats to security from the past to today.
How to think like an attacker?
Step 1. Perform footprint analysis (reconnaissance).
Step 2. Enumerate information.
Step 3. Manipulate users to gain access.
Step 4. Escalate privileges.
Step 5. Gather additional passwords and secrets.
Step 6. Install backdoors.
Step 7. Leverage the compromised system.
The trade off between open versus closed networks.
Developing a security policy for the company or organization is a must.
Understanding the common security threats and the different types of network attacks.
Finally, general mitigation techniques and the security appliances and applications
Data Communications,Data Networks,computer communications,multiplexing,spread spectrum,protocol architecture,data link protocols,signal encoding techniques,transmission media,asynchronous transfer mode
Introduction to computer according to veta curicullumSteven Alphonce
this notes prepared to enable the trainee to describe computer system,Describe connection ports,procedures for connecting peripherals to micro-computer system and test the system
The list of open java online courses from the world famous universities. All courses are actual and available using Coursera online education platform.
Introduction to Computer Networking - School level Matthew Bulat
What is computer networking? Why is networking important for yourself and business? How is networking achieved in a school environment? How can satellite networking help in remote location? How can I learn more on networking for free?
Learn to identify parts of a computer, hardware and software, operate the mouse and keyboard and become familiar with the MS Windows X/P Operating System.
These slides present various communications and measurement technology applied for smart grid. Later of the class I will present the same at advance level.
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5.5. Introduction to NetworkingIntroduction to Networking
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References
• Held G., “Internetworking LANs and WANs – Concepts,
Techniques and Methods”, Wiley, 2nd Ed., 1998
Comment: Good at concepts
• Stallings W., “Data and Computer Communications”, Prentice
Hall, 7th Ed., 2004
Comment: Good at concepts and very up-to-date
• Forouzan B. A, “Data Communications and Networking”,
McGraw-Hill, 2nd Ed., 2000
Comment: Many good revision questions at ends of chapters
• Redmond W., “MCSE Training Kit: Networking Essentials
Plus”, Microsoft Press, 2000
Comment: Practical oriented
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What is a Network?
A network consists of 2 or more computers
connected together, and they can communicate and
share resources (e.g. information)
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Why Networking?
• Sharing information — i.e. data communication
• Do you prefer these?
• Or this?
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• Sharing hardware or software
• Centralize administration and support
• E.g. print document
• E.g. Internet-based, so everyone can access the same
administrative or support application from their PCs
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How many kinds of Networks?
• Depending on one’s perspective, we can classify
networks in different ways
• Based on transmission media: Wired (UTP, coaxial
cables, fiber-optic cables) and Wireless
• Based on network size: LAN and WAN (and MAN)
• Based on management method: Peer-to-peer and
Client/Server
• Based on topology (connectivity): Bus, Star, Ring …
:
:
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• Two main categories:
– Guided ― wires, cables
– Unguided ― wireless transmission, e.g. radio,
microwave, infrared, sound, sonar
• We will concentrate on guided media here:
– Twisted-Pair cables:
Unshielded Twisted-Pair (UTP) cables
Shielded Twisted-Pair (STP) cables
– Coaxial cables
– Fiber-optic cables
Transmission Media
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• If the pair of wires are not twisted, electromagnetic
noises from, e.g., motors, will affect the closer wire more
than the further one, thereby causing errors
Twisted-Pair Cables
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Unshielded Twisted-Pair (UTP)
• Typically wrapped inside a plastic cover (for mechanical
protection)
• A sample UTP cable with 5 unshielded twisted pairs of wires
MetalInsulator
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Shielded Twisted-Pair (STP)
• STP cables are similar to UTP cables, except there
is a metal foil or braided-metal-mesh cover that
encases each pair of insulated wires
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Categories of UTP Cables
EIA classifies UTP cables according to the quality:
• Category 1 ― the lowest quality, only good for voice,
mainly found in very old buildings, not recommended now
• Category 2 ― good for voice and low data rates (up to
4Mbps for low-speed token ring networks)
• Category 3 ― at least 3 twists per foot, for up to 10 Mbps
(common in phone networks in residential buildings)
• Category 4 ― up to 16 Mbps (mainly for token rings)
• Category 5 (or 5e) ― up to 100 Mbps (common for
networks targeted for high-speed data communications)
• Category 6 ― more twists than Cat 5, up to 1 Gbps
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Coaxial Cables
• In general, coaxial cables, or coax, carry signals of
higher freq (100KHz–500MHz) than UTP cables
• Outer metallic wrapping serves both as a shield
against noise and as the second conductor that
completes the circuit
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Fiber-Optic Cables
• Light travels at 3×108
ms-1
in free space and is the
fastest possible speed in the Universe
• Light slows down in denser media, e.g. glass
• Refraction occurs at interface, with light bending away
from the normal when it enters a less dense medium
• Beyond the critical angle ⇒ total internal reflection
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• An optical fiber consists of a core (denser material)
and a cladding (less dense material)
• Simplest one is a multimode step-index optical fiber
• Multimode = multiple paths, whereas step-index =
refractive index follows a step-function profile (i.e.
an abrupt change of refractive index between the
core and the cladding)
• Light bounces back and forth along the core
• Common light sources: LEDs and lasers
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Advantages and Disadvantages
Noise resistance ― external light is blocked by outer
jacket
Less signal attenuation ― a signal can run for miles
without regeneration (currently, the lowest measured
loss is about ~4% or 0.16dB per km)
Higher bandwidth ― currently, limits on data rates come
from the signal generation/reception technology, not the
fiber itself
Cost ― Optical fibers are expensive
Installation/maintenance ― any crack in the core will
degrade the signal, and all connections must be perfectly
aligned
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LAN and WAN
• Local Area Network (LAN)
• Small network, short distance
• A room, a floor, a building
• Limited by no. of computers and distance covered
• Usually one kind of technology throughout the LAN
• Serve a department within an organization
• Examples:
• Network inside the Student Computer Room
• Network inside CF502
• Network inside your home
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• Wide Area Network (WAN)
• A network that uses long-range telecommunication links
to connect 2 or more LANs/computers housed in different
places far apart.
• Towns, states, countries
• Examples:
• Network of our Campus
• Internet
WAN
Student
Computer Centre
Your home
USA
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• Example WAN technologies:
• ISDN – Integrated Service Digital Network
• Basic rate: 192 Kbps Primary rate: 1.544Mbps
• T-Carriers ― basically digital phone lines
• T1: 1.544Mbps T3: 28×T1
• Frame relay
• Each link offers 1.544Mbps or even higher
• ATM – Asynchronous Transfer Mode
• Support B-ISDN: 155Mbps or 622Mbps or higher
• SONET – Synchronous Optical Network
• Basic rate OC1: 51.84Mbps
• Support OC12 and up to OC192 (9953.28Mbps) or
even higher in the future
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• Example of WAN: Broadband Cable Network
• Cable TV services have been extensively developed in most
modern cities
• Cable TV companies try to make use of their coaxial cable
installed (that are supposed to carry TV signals) to deliver
broadband data services
• Many cable network wiring has been replaced with hybrid
fiber-coax (HFC) ― i.e. use of fiber-optic cable to connect
to the subscribers’ buildings, and then the original coaxial
cable to connect to each household
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The connection is shared by a
number of subscribers, hence
may raise performance and
security problems
Fiber-optic cable
Cable companyCoaxial
Cable
TV
PC
Cable
Drop
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• Cable is an asymmetrical technology
• Downstream: max 36 Mbps
• Upstream: max 10 Mbps
• May be reduced to 3 – 10 Mbps downstream and 2
Mbps upstream, depending on no. of subscribers
• Need a special cable modem Ethernet
link to PC
Coaxial link
from cable TV
socket
Teryon Cable Modem
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Peer-to-Peer Networks
• Peer-to-peer network is also called workgroup
• No hierarchy among computers ⇒ all are equal
• No administrator responsible for the network
Peer-to-peer
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• Advantages of peer-to-peer networks:
• Low cost
• Simple to configure
• User has full accessibility of the computer
• Disadvantages of peer-to-peer networks:
• May have duplication in resources
• Difficult to uphold security policy
• Difficult to handle uneven loading
• Where peer-to-peer network is appropriate:
• 10 or less users
• No specialized services required
• Security is not an issue
• Only limited growth in the foreseeable future
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Clients and Servers
• Network ClientsClients (WorkstationWorkstation)
• Computers that request network resources or services
• Network ServersServers
• Computers that manage and provide network resources
and services to clients
• Usually have more processing power, memory and
hard disk space than clients
• Run Network Operating System that can manage not
only data, but also users, groups, security, and
applications on the network
• Servers often have a more stringent requirement on its
performance and reliability
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• Advantages of client/server networks
• Facilitate resource sharing – centrally administrate and
control
• Facilitate system backup and improve fault tolerance
• Enhance security – only administrator can have access
to Server
• Support more users – difficult to achieve with peer-to-
peer networks
• Disadvantages of client/server networks
• High cost for Servers
• Need expert to configure the network
• Introduce a single point of failure to the system
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Topology ― 3 basic types
• How so many computers are connected together?
Bus Topology Ring Topology
Star Topology
Hub
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• Bus Topology
• Simple and low-cost
• A single cable called a trunk (backbone, segment)
• Only one computer can send messages at a time
• Passive topology - computer only listen for, not
regenerate data
• Star Topology
• Each computer has a cable connected to a single point
• More cabling, hence higher cost
• All signals transmission through the hub; if down, entire
network down
• Depending on the intelligence of hub, two or more
computers may send message at the same time
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How to construct a network
with Bus / Star Topology?
Star Topology
Bus Topology
BNC T-Connector
Coaxial
cable
Network Card
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• Ring Topology
• Every computer serves as
a repeater to boost signals
• Typical way to send data:
• Token passing
• only the computer who
gets the token can send
data
• Disadvantages
• Difficult to add computers
• More expensive
• If one computer fails, whole network fails
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