Information Technology Basics

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• Information Technology Basics

Triumph is just umph added to try! Anon If one
advances confidently in the direction of his
dreams, he will meet with a success unimagined
in common hours... If you have built castles in
the air, that is where they should be. Now put
the foundations under them. - Henry David
Thoreau
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Target, Purpose Method

• Target Parents, School Administrators,
  Counselors and Teachers
• Purpose Provide a QUICK overview into
  Information Technology so the audience
  understands the skill sets needed by students to
  enter this exciting career field
• Method What follows is a snap shot summary of
  the skills covered by students in the CNS
  department at TSTC Waco

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Overview

• Computer systems Internet Intro
• Measurement
• Logic Numbering
• Operating Systems
• Networks
• Network Components
• Network Services

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Computer Systems

• Computer systems consists of hardware and
  software components
• Hardware is the physical equipment such as the
  case, floppy disk drives, keyboard, monitor,
  cables, speakers, and printers
• Software (AKA program) instructs the computer on
  how to operate. Operations may include
  identifying, accessing, and processing
  information

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Computer Systems

• Two types of software operating systems and
  applications
• Application software accepts input from the user
  and then manipulates it to achieve a result,
  known as the output Examples of applications
  include word processors, database programs,
  spreadsheets, web browsers, web development
  tools, and graphic design tools
• Operating Systems (OS) manages all the other
  programs in a computer
• Provides the operating environment with the
  applications that are used to access resources

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Computer Types

• Mainframes
• Centralized computers, usually housed in secure
  climate controlled computer rooms
• Users interface with the computers via "dumb
  terminals"
• Dumb terminals are low cost I/O devices, usually
  consist of a monitor, keyboard, and a
  communication port to talk to the mainframe

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Computer Types

• Mainframes
• There are several disadvantages of mainframes
• Character based applications
• Lack of vendor operating system standards and
  interoperability in multi-vendor environments
• Expensive, with a high cost for set up,
  maintenance, and initial equipment
• Potential single point of failure (non-fault
  tolerant configurations)
• Timesharing systems, which means that there is a
  potential for a bottleneck

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Computer Types

• Personal Computer (PC)
• Standalone device, independent of all other
  computers
• Graphical User Interface (GUI) gained popularity
  w/ users
• GUI advantage user does not have to remember
  complicated commands to execute a program
• PC power has risen to the point that it can
  perform enterprise level functions

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Computer Types

• Personal Computer (PC)
• There are several advantages of PC computing
• Standardized hardware
• Standardized, highly interoperable operating
  systems
• GUI interface
• Low cost devices (when compared to mainframes),
  low cost of entry
• Distributed computing
• User flexibility
• High productivity applications

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Computer Types

• Personal Computer (PC)
• There are several disadvantages of PC computing
• Desktop computers cost, on average, five times as
  much as dumb terminals, according to some
  industry estimates
• No centralized backup
• No centralized management
• Security risks can be greater (physical, data
  access, and virus security)
• High management and maintenance costs, although
  they are generally cheaper to maintain than
  mainframes

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Backwoods PC
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Connecting Computer Systems

• The PC as a standalone device may be adequate for
  a home computer, but businesses, government
  offices, and schools need to exchange information
  and share equipment and resources.
• In order to do this, a method was developed to
  connect individual computers to share common
  resources
• This method is called networking.
• A network is simply a group of computers
  connected so their resources can be shared.

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Connecting Computer Systems

• A computer networks saves the expense of having
  to buy peripheral equipment like printers for
  each computer.

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Birth of the Internet

• Oct 1957 Sputnik is launched and free world
  freaks
• 1960s - The U.S. Department of Defense (DoD)
  recognizes need to establish redundant
  communications links. Primary motivation was to
  maintain communications if a nuclear war resulted
  in the mass destruction and breakdown of
  traditional communications channels
• 1970s - Advanced Research Projects Agency
  Network (ARPANET) begins, no one anticipated the
  network (s) would grow exponentially. Throughout
  70s, more nodes added, (Here Overseas)
• 1980s - Domain Name System (DNS) introduced in
  1984, provides a map of "friendly" host names to
  IP addresses.
• More efficient and convenient than previous
  methods

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Birth of the Internet

• 1990s - ARPANET evolved into the Internet, with
  the U.S. government getting involved in pushing
  the development of the so-called information
  superhighway
• Today, millions of sites on the World Wide Web,
  with millions of host computers

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Measurement-related Terminology

• Bit Smallest unit of data in a computer. A bit
  takes the value of either one or zero, and it is
  the binary format in which data is processed by
  computers 
• Byte A byte is a unit of measure used to
  describe the size of a data file, the amount of
  space on a disk or other storage medium. One byte
  eight bits
• Nibble A nibble is half a byte or four data
  bits
• Octets A series of eight bits use to turn
  processes off or on  

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Measurement-related Terminology

• Kilobyte (KB) A kilobyte is 1,024 (or
  approximately 1,000) bytes. 
• Kilobit (Kb) A kilobit is 1,024 (or
  approximately 1,000) bits.
• Megabyte (MB) A megabyte is 1,048,576 bytes (or
  approximately 1,000,000 bytes). 
• Note that a capital B indicates bytes while a
  lower case b indicates bits.

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Measurement-related Terminology

• The following terms are standard measurements of
  the amount of data transferred over a network
  connection.
• Kilobits per second (Kbps) Kbps is a data
  transfer rate of approximately 1,000 bits per
  second. 
• Megabytes per second (MBps) MBps is a data
  transfer rate of approximately 1,000,000 bytes
  per second. 
• Megabits per second (Mbps) Mbps is a data
  transfer rate of approximately 1,000,000 bits per
  second.

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Measurement-related Terminology

• Hertz (Hz) unit of measurement of frequency. It
  is the rate of change in the state or cycle in a
  sound wave, alternating current, or other
  cyclical waveform.
• Common measurement of the speed of a processing
  chip.
• Megahertz (MHz) One million cycles per second.
  common measurement of the speed of a processing
  chip 
• Gigahertz (GHz) One billion (1,000,000,000)
  cycles per second

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Boolean Logic Gates

• Computers are built from various types of
  electronic circuits. These circuits depend on
  what are called AND, OR, NOT, and NOR logic
  "gates."
• These gates are characterized by how they respond
  to input signals.

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Boolean Logic Gates

• AND
• AND gate acts as follows if either input is off,
  the output is off.
• AND is like multiplication

Truth Table
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Boolean Logic Gates

• OR
• OR gate acts as follows if either input is on,
  the output is on
• OR is like addition

Truth Table
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Boolean Logic Gates

• NOT
• A NOT gate acts as follows if the input is on,
  the output is off, and vice versa.
• NOT is the opposite of the input

Truth Table
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Boolean Logic Gates

• NOR
• The NOR gate is a combination of the OR and NOT
  gates and should not be presented as a primary
  gate. A NOR gate acts as follows if either input
  is on, the output is off.

Truth Table
First perform the OR operation, then perform the
NOT operation.
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Numbering Systems

• Decimal (base 10)
• uses 10 symbols
• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
• Binary (base 2)
• uses 2 symbols
• 0, 1
• Hexadecimal (base 16)
• uses 16 symbols
• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

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Numbering Systems
Base 10
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Decimal to Binary ConversionMethod 1

• Convert the decimal number 192 into a binary
  number.
• 192/2 96 with a remainder of 0
• 96/2 48 with a remainder of 0
• 48/2 24 with a remainder of 0
• 24/2 12 with a remainder of 0
• 12/2 6 with a remainder of 0
• 6/2 3 with a remainder of 0
• 3/2 1 with a remainder of 1
• 1/2 0 with a remainder of 1
• Write down all the remainders, backwards, and you
  have the binary number 11000000.

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Decimal to Binary ConversionMethod 2

• Convert the decimal number 192 into a binary
  number. First find the largest number that is a
  power of 2 that you can subtract from the
  original number. Repeat the process until there
  is nothing left to subtract.
• 192-128 64 128s used 1
• 64-64 0 64s used 1
• 32s used 0
• 16s used 0
• 8s used 0
• 4s used 0
• 2s used 0
• 1s used 0
• Write down the 0s 1s from top to bottom, and
  you have the binary number 11000000.

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Binary to Decimal ConversionMethod 1

• Convert the decimal number 213 into a binary
  number. First find the largest number that is a
  power of 2 that you can subtract from the
  original number. Repeat the process until there
  is nothing left to subtract.
• 213-128 85 128s used 1
• 85-64 21 64s used 1
• (32 cannot be subtracted from 21) 32s
  used 0
• 21-16 5 16s used 1
• (8 cannot be subtracted from 5) 8s
  used 0
• 5-4 1 4s used 1
• (2 cannot be subtracted from 1) 2s
  used 0
• 1-1 0 1s used 1
• Write down the 0s 1s from top to bottom, and
  you have the binary number 11010101.

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Binary to Decimal ConversionMethod 2

• From right to left, write the values of the
  powers of 2 above each binary number. Then add
  up the values where a 1 exist.

128 32 16 4 1 181
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Binary to Decimal ConversionMethod 2

• Start from the left with the first 1 in the
  binary number. Write down a 1 below it.
• Then look at the next number to the right
• if it is a 0, double the previous number and
  write it down
• if it is a 1, double the previous number and add
  1 to it, then write it down
• Continue this until you reach the last 0 or 1 in
  the binary number.
• The last number you write down is the decimal
  equivalent of the binary number.

1
3
6
13
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Hexadecimal to Decimal Conversion

• Each number place represents a power of 16
• Given the hexadecimal number 12A
• 1 X 256 256
• 2 X 16 32
• A X 1 10 (A 10 in hex)
• 298

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Hexadecimal to Binary Conversion
To convert a hex number to a binary number, each
hex bit 4 binary digits Given the hex number
A 3 A is the decimal number 10 10 in binary
is 1 0 1 0 8 4 2 1 (binary number places -
4 bits) 1 0 1 0 3 is the decimal number
3 3 in binary is 0 0 1 1 8 4 2 1 (binary
number places - 4 bits) 0 0 1 1 hex A 3
1 0 1 0 0 0 1 1 in binary
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Basic Functions of an Operating Systems

• Input signals from the keyboard or mouse
• Processing - Manipulating data according to the
  user's instructions
• Output signals to the video screen or printer
• Storage keeping track of files for later use.
  Examples USB drives, floppy disks, hard drives
  optical media

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Operating Systems

• Operating Systems (OS) are software programs that
  control thousands of operations, provide an
  interface between the user and the computer, and
  run applications
• An OS is designed to control the operations of
  programs such as Web browsers, word processors,
  and e-mail programs
• Computers that are capable of handling concurrent
  users and multiple jobs are often called "network
  servers" or simply "servers." Servers have
  operating systems installed called Network
  Operating Systems (NOS)

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Operating Systems

• Three basic elements make up an operating system.
  
• User interface A user interacts with the
  computer's OS through the user interface. Simply,
  the part of the operating system a person can use
  to issue commands
• Kernel The core of the OS. The kernel is
  responsible for loading and running programs
  (processes) and for managing input and output.
• File management system What the OS uses to
  organize and manage files. Most operating systems
  use a hierarchical file system in which files are
  organized into directories under a tree
  structure. The beginning of the directory system
  is referred to as the root directory.

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Operating Systems Functions

• Regardless of the size or complexity of the
  computer or its operating system, all operating
  systems perform the same basic functions
• File and folder management
• Management of applications
• Support for built-in utility programs
• Access control to computer's hardware

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Operating Systems Functions
What type of software has access to the BIOS?
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Operating Systems - Terminology

• Multi-user Two or more users running programs
  and sharing peripheral devices, such as a
  printer, at the same time.
• Multi-tasking A computer's capability to run
  multiple applications at the same time.
• Multi-processing Allows a computer to have two
  or more CPUs (Central Processing Unit) that
  programs share.
• Multi-threading The capability of a program to
  be broken into smaller parts that can be loaded
  as needed by the OS. Multi-threading allows
  individual programs to be multi-tasked.
• Today, almost all operating systems are
  multi-user, multi-tasking, and support
  multi-threading.

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(No Transcript)
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Computer Networks

• A computer network is defined as having two or
  more devices (such as workstations, printers, or
  servers) that are linked together for the purpose
  of sharing information, and other resources

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Network Administration

• The ongoing task of maintaining and adapting the
  network to changing conditions belongs to
  administrators and other IT support personnel
• System/Network administrator responsibilities
  include setting up new user accounts and
  services, monitoring network performance, and
  repairing network failures
• They evaluate new technologies and requirements,
  administrators must measure the benefits of the
  new features against the issues, costs, and
  problems they may introduce to the network

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Network Overview

• By using local-area network (LAN) and wide-area
  network (WAN) technologies, many computers are
  interconnected to provide services to their users
  
• In providing services, networked computers take
  on different roles or functions in relation to
  each other
• Two computers typically communicate with each
  other by using request/response protocols
• The requester takes on the role of a client, and
  the responder takes on the role of a server

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Peer-to Peer Networks

• Networked computers act as equal partners, or
  peers, to each other. As peers, each computer can
  take on the client function or the server
  function alternately.
• Individual users control their own resources.
  They may decide to share certain files with other
  users and may require passwords before they allow
  others to access their resources.
• A peer-to-peer network works well with a small
  number of computers, perhaps 10 or fewer.

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Client/Server Networks

• In a client/server network arrangement, network
  services are located in a dedicated computer
  whose only function is to respond to the requests
  of clients.
• The server contains the file, print, application,
  security, and other services in a central
  computer that is continuously available to
  respond to client requests.
• Typically, desktop computers function as clients
  and one or more computers with additional
  processing power, memory, and specialized
  software function as servers.

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Local-Area Networks

• LANs connect many computers in a relatively small
  geographical area such as a home, an office, a
  building, or a campus
• The general shape or layout of a LAN is called
  its topology
• LANs require the networked computers to share the
  communications channel that connects them. The
  communications channel that they all share is
  called the medium

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Wide-Area Networks

• WANs connect networks across large geographical
  boundaries such as cities, states, and countries
• Wide area connections use point-to-point, serial
  communications lines. Called point-to-point
  because they connect nodes, one on each side
• Wide area connections use utility companies
  communications facilities
• WANs typically connect networks and operate at
  lower speeds than LANs. WANs, however, provide
  the means for connecting single computers and
  many LANs over large distances

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Network Interface Card

• A Network Interface Card (NIC) plugs into a
  motherboard and provides ports for the network
  cable connections. It is the computer's interface
  with the LAN
• Important considerations to bear in mind when
  selecting a NIC to use on a network
• The type of network NICs are designed for
  Ethernet LANs, Token Ring, FDDI...
• The type of media twisted-pair, coaxial,
  fiber-optic, or wireless
• The type of computer system bus PCI or ISA

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Setting the IP Address

• In a TCP/IP-based LAN, PCs use Internet Protocol
  (IP) addresses to logically identify each other
• IP addresses are unique, hierarchical 32-bit
  binary numbers
• 190.100.5.54 is an example of an IP address. This
  is known as dotted decimal annotation
• A secondary dotted decimal number, known as the
  subnet mask, always accompanies an IP address.
  The dotted decimal number 255.255.0.0 is a subnet
  mask
• The IP address is unique for each host and
  resides in the computer driver software for the
  NIC

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Setting an IP Address
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DHCP Servers

• Common and efficient way for computers on a large
  network to obtain an IP address is through a
  Dynamic Host Configuration Protocol (DHCP)
  server. DHCP is a software utility that runs on a
  computer and is designed to assign IP addresses
  to PCs.
• The IP address information a DHCP server can hand
  out to hosts starting up on the network includes
  the following
• An IP address
• A subnet mask
• Default Gateway
• Optional values, such as a Domain Name System
  (DNS) server address

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Default Gateway

• The default gateway is the "near side" interface
  of the router, the interface on the router to
  which the local computer's network segment or
  wire is attached
• In order for each computer to recognize its
  default gateway, the corresponding near side
  router interface IP address has to be entered
  into the host Internet Protocol (TCP/IP)
  Properties Dialog Box
• The default gateway allows communication with
  other networks

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Domain Name System

• Most hosts are identified on the Internet by
  friendly computer names known as domain names
• The Domain Name System (DNS) is used to translate
  computer names such as cisco.com to their
  corresponding unique IP address

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Physical Topologies

• Physical topology defines the way computer and
  other devices are connected

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Physical vs. Logical Topology

• Networks have both a physical and logical
  topology
• Physical topology Refers to the layout of the
  devices and media
• Logical topology Refers to the paths that
  signals travel from one point on the network to
  another. That is, the way in which data accesses
  media and transmits packets across it
• A network can have a one type of physical
  topology and a completely different type of
  logical topology or they can be the same

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Types of Media

• Coaxial cable - copper-cored cable surrounded by
  a heavy shielding. Uses BNC connector.
• Twisted pair - Shielded and Unshielded
• Shielded - Shielded Twisted-Pair (STP) cable
  combines the techniques of cancellation and the
  twisting of wires with shielding. Uses STP
  connector
• Unshielded Twisted-Pair (UTP) cable is used in a
  variety of networks. It has two or four pairs of
  wires. Uses RJ45 connector
• Fiber-optic cable is a networking medium capable
  of conducting modulated light transmissions.

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Wiring example NOT!!!
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Networking Devices

• Hub - device used to extend an Ethernet signal to
  allow more devices to communicate with each other
• Bridges connect network segments. The bridge
  makes intelligent decisions about whether to
  allow signals onto the next segment of a network
• Switch (AKA multi-port bridge) is a more
  sophisticated device than a bridge, uses similar
  logic but more ports
• Routers are the most sophisticated
  internetworking devices. They are slower than
  bridges and switches, but make "smart" decisions
  on how to route (or send) packets received on one
  port to a network on another port.

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Ethernet

• The Ethernet architecture is now the most popular
  type of LAN (media access) architecture
• The Ethernet architecture is based on the IEEE
  802.3 standard. The IEEE 802.3 standard specifies
  that a network implements the Carrier Sense
  Multiple Access with Collision Detection
  (CSMA/CD) access control method

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OSI Model

• The Open Systems Interconnection (OSI) reference
  model is an industry standard framework that is
  used to divide the functions of networking into
  seven distinct layers.

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TCP/IP
DOD TCP/IP network model is based on the OSI
reference model and is the predominant protocol
suite used in networking
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IP v4 Addressing

• For any two systems to communicate, they must be
  able to logially identify and locate each other
• Each computer in a TCP/IP network must be given
  at least one unique identifier, or address
• This address allows one computer to locate
  another on a network

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IP v4 Addressing

• By using the network identifier, IP can deliver a
  packet to the destination network
• Once the packet arrives at a router connected to
  the destination network, IP must locate the
  particular point where the destination computer
  is connected to that network

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IP v4 Addressing

• Every IP address has two parts.
• The first part tells which network the system is
  located on
• The second part, called the host, identifies the
  particular machine on that network
• Called a hierarchical address, because it
  contains different levels
• Example 192.168.1.8 (dotted decimal notation)
  11000000.10101000.00000001.00001000. (binary
  notation)
• What are each of these four groups called?

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NOS Services

• Networking Operating Systems (NOSs) are designed
  to provide network processes to clients and peers
  
• Network services include the World Wide Web
  (WWW), file sharing, mail exchange, directory
  services, remote management, and print services
• It is important to understand these network
  processes are referred to as "Services" in
  Windows 2000, "Daemons" in Linux, and "Netware
  Loadable Modules" (NLMs) in Novell 

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TCP/IP-Based Services
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Remote Access Benefits

• Some popular uses of remote access include the
  following
• Connecting branch offices to one another
• Providing a means for employees to connect to the
  network after business hours
• Allowing employees to telecommute that is, work
  at home on a part-time or full-time basis
• Enabling employees who are on the road, such as
  traveling salespeople or executives on business
  trips, to connect to the corporate network
• Providing the company's clients or partners
  access to network resources

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Telnet

• Telnet is the main Internet protocol for creating
  a connection with a remote machine. It gives the
  user the opportunity to be on one computer system
  and do work on another.
• The telnet command may be written in the follow
  ways
• telnet lthostname IP addressgt
• telnet 168.35.236.2
• telnet computername.com

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Directory Services

• A directory service provides system
  administrators with centralized control of all
  users and resources across the entire network
• Provides ability to organize information
• Simplifies management of the network by providing
  a standard interface for common system
  administration tasks

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Mail

• Mail may be the most important network process
• Mail provides users with a mechanism to send and
  receive electronic mail (e-mail)
• Mail services are comprised of a combination of
  the following components
• Mail Transfer Agent (MTA) - SMTP, Sendmail
• Mail User Agent (MUA) - Eudora, Outlook, Pine
• Mail Delivery Agent (MDA) - IMAP, POP3

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Mail

• Many mail servers include other features,
  including support for
• Lightweight Directory Access Protocol (LDAP)
  provides corporate address book sharing
• Web interface programs allow clients to read and
  compose mail using a Web browser

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Types of Networks
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Scripting Environments Languages

• A script is a simple text program that allows the
  user to perform many automated tasks at once
• Depending on their design, scripts can range from
  single lines of code to lengthy amounts of
  programming logic

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Domains

• A Domain is a logical grouping of networked
  computers that share a central directory or
  database.
• Some advantages of domains include
• Centralized administration
• A single logon process that enables users to
  access network resources
• A domain provides the ability to expand a network
  to extremely large sizes throughout every corner
  of the world.

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Summary

• So far we have covered
• Computer systems Internet Intro
• Measurement
• Logic Numbering
• Operating Systems
• Networks
• Network Components
• Network Services
• QUESTIONS???

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Take Aways

• By now you should realize students entering this
  program need to possess
• Excellent reading ability (2-10K pages/year)
• Analytical skills (troubleshooting is critical)
• Synthesis skills (must draw from multiple
  disciplines to develop solutions)
• Ability to apply math skills (especially for
  addressing electronics)