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Computer Networks -Introduction Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco Instructor: Ahmed Hussein Farah 1 In this Intro: About the Instructor. Course Contents.
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Transcript of Computer Networks -Introduction · Computer Networks -Introduction Wednesday, March 5,2014 Computer...

  • Computer Networks

    -Introduction

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 1

    In this Intro:

    About the Instructor.

    Course Contents.

  • Computer Networks

    -Introduction

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 2

    About the Instructor:

    As an Instructor.

    As an Employee.

    As IT Consultant.

  • Computer Networks

    -Introduction

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 3

    As an Instructor:

    More the 7 years instruction: in ComputerHardware,

    Networking Administration and Software Engineering.

    Teaching in Institutes and Universities: International

    Horn University(2010-2011), SITCO(2005-2009),

    SIDAM.

  • Computer Networks

    -Introduction

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 4

    As an Employee:

    Currently as Network Security Administrator

    About 8 years, I dealt with IT infrastructure such as Computers, Servers, Networking Devices, Switches, Routers, Firewalls….etc

    I also administer, Configure, Secure and Install Windows Server/Client Network Controllers know as Domain Networks.

    Train IT Officers in Regional Offices when we enforce or upgrade Network Systems….

  • Computer Networks

    -Introduction

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 5

    As an IT Consultant:

    I have my Own Consulting Company Since 2012

    Its for IT Services which Include:

    Cabling(Electricity/Telephones/Network),

    PBX systems, VSATs,

    Servers Deployment, Domain Network Setup,

    Poin-to-Point and Multipoint Networks,

    Security and Much more….

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 6

    General Uses of Networks:

    Work:

    – Email, file sharing, printing, …

    Home:

    – Movies / songs, news, calls / video, messaging, e-commerce,

    Mobile:

    – Calls / texts, games, videos, maps, information access …

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 7

    Uses of Networks

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 8

    For User Communication

    From the telephone onwards:

    – VoIP (voice-over-IP)

    – Video conferencing

    – Instant messaging

    – Social networking

  • Computer Networks

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    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 9

    For Resource Sharing

    Many users may access the same underlying resource

    – E.g., printers, search index, machines in the cloud

    More cost effective than dedicated resources per user

    – Even network links are shared via statistical multiplexing

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 10

    For Statistical Multiplexing

    Sharing of network bandwidth between users according to

    the statistics of their demand:

    – (Multiplexing just means sharing)

    – Useful because users are mostly idle and their traffic is busty.

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 11

    For Content Delivery

    Same content is delivered to many users

    – Videos (large), songs, apps and upgrades, web pages, …

    More efficient than sending a copy all the way to each user

    – Uses replicas in the network.

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 12

    For Computer Communication

    To let computers interact with other computers

    – E.g., e-commerce, reservations…

    Enables automated information processing across different

    parties

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 13

    To Connect Computers to the Physical World:

    For gathering sensor data, and for manipulating the world

    – E.g., webcams, location on mobile phones, door locks, …

    This is a rich, emerging usage

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 14

    The Value of Connectivity

    “Metcalfe’s Law” ~1980:

    – “The value of a network of N nodes is proportional to N2”

    – Large networks are relatively more valuable than small ones.

    Bob Metcalfe

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 15

    Networks by Type:

    WiFi (802.11)

    Enterprise / Ethernet

    ISP (Internet Service Provider)

    Cable / DSL

    Mobile phone / cellular (2G, 3G, 4G)

    Bluetooth

    Telephone

    Satellite ...

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 16

    Networks by Scale:

    Scale Type Example Vicinity PAN (Personal Area Network) Bluetooth (e.g.,

    headset)

    Building LAN (Local Area Network) WiFi, Ethernet

    City MAN (Metropolitan Area Network) Cable, DSL

    Country WAN (Wide Area Network) Large ISP

    Planet The Internet (network of all

    networks)

    The Internet!

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 17

    Internetworks and the Internet:

    An internetwork, or internet, is what you get when you join

    networks together.

    – Just another network

    The Internet (capital “I”) is the internet we all use

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 18

    Understanding Local Area Networks(LANs)

  • Computer Networks

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    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 19

    Local Area Network

    a “network” is two or more computers that exchange data.

    A local area network (LAN) is a group of these computers that are

    confined to a small geographic area, usually one building. Setting

    up a LAN requires computers with network adapters, central

    connecting devices to connect those computers together, and

    a numbering scheme (such as IP addresses) to differentiate

    from one computer to the next.

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 20

    Networks are used to exchange data. But Important reasons that organizations need networks? These reasons can be divided into four categories:

    Sharing: Networks permit the sharing of files, databases, and media.

    Communication: Networks are critical for email, instant messaging, and faxing capabilities.

    Organization: Networks centralize data and make it more accessible, which increases the efficiency and speed with which this information can be accessed.

    Money: A network should ultimately save a company money, often by aiding in the budgeting process and/or increasing productivity.

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 21

    Basic LAN documentation

  • Computer Networks

    -Week1

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 22

    In the Figure, several hosts connect to the hub, including the following:

    A server: A server is used to centralize data and share it (or serve it) with other computers on the network.

    A PC (personal computer): A PC usually acts as a client on the network, most likely getting its information from the server. A PC can also store information locally.

    A Mac (Macintosh) computer: As another type of client computer, a Mac can store information locally or get it from the server.

    A laptop: This could be a PC or a Mac. Despite its portability, a laptop stores and accesses data the same way the other network computers do.

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 23

    In this Week:

    1. Network Card and Data Transfer

    2. Networking Devices, UTP Cable, and Topologies.

    3. LAN Architecture: (a) Peer-to-Peer, (b) Client Server,

    ( c) Distributed Computing and (d) Centralized

    Computing.

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 24

    Network components and Terminology

    Data

    Node

    Client

    Server

    Peer

    Network adapter

    Hub

    Switch

    Router

    Media

    Transport Protocol

    Bandwidth

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 25

    1. Network Card and Data Transfer

  • Computer Networks

    -Week2

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    Instructor: Ahmed Hussein Farah 26

  • Computer Networks

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    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

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    A network card: A network

    adapter, also known as a

    network interface card or

    NIC,

    NIC: is the device that

    enables you to send and

    receive data to and from

    your computer.

    NIC can be Wired or

    Wireless.

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 28

    The network adapter might be integrated into the

    motherboard or act as a separate device that connects to a

    PCI slot, or perhaps a PC card slot or USB port.

    An adapter can connect to the network by cable (wired) or

    by air (wireless).

    Network adapters also have a software component known as

    a driver, which defines how the card will interact with the

    operating system;

  • Computer Networks

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    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 29

    View a Network Adapter

  • Computer Networks

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    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 30

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 31

    Wireless Access Point

    The wireless access point (WAP) acts as the central connecting device for the network

    Wireless networks can consist of many types of devices other than traditional PCs:

    Smart phones

    PDAs

    Tablet computers

    Micro computers

    PCs and laptops equipped with wireless network adapters can connect to these networks as well

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 32

    Wireless LAN Diagram:

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 33

    Wired LAN Documentation:

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 34

    Demos:

    Device Manager Showing Network Adapters

    Network Adapter Properties

    IP Address

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 35

    Check the Driver, MAC(Physical) and IP your NIC.

    1. Checking the Driver, Steps: Rclick Computer -> manage-

    > device manager ->network adapters.

    2. Check the MAC and IP address of your XP Computer,

    Steps: start -> run-> cmd -> type: ipconfig /all -> enter.

    3. Check the MAC and IP address of your Window7 PC,

    Steps: start -> run-> cmd -> ipconfig /all -> enter.

    4. Write down the MAC and IP of your PC.

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 36

    Serial Data Transfer

    Serial data transfer is the transfer of one bit at a time—in

    other words, transfer in a single-bit stream, like a one lane

    highway

    On the network cable, data travels in a single bit stream

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 37

    Data Transfer Rate

    Data transfer rate is the maximum bits per second (bps) that

    can be transmitted over a network

    Rated in bits, and signified with a lowercase b (for example,

    10 Mbps)

    The lowercase b is for bits and an upper case B stands for

    bytes (for example 10 MB)

    Types of Transfers

    Broadcast sends data to every other host on the network

    Unicast sends data to a specific host

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 38

    IP Address

    Most every computer and many other devices have an Internet Protocol (IP) address

    An IP address uniquely identifies your device and the associated network and allows each device to send and receive information

    A typical example of an IPv4 address would be 192.168.1.1

    Every IP address is broken down into two parts by a subnet address

    Network ID 192.168.1

    Host ID 1

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 39

    Subnet Mask

    The subnet mask is a group of four numbers that define what

    IP network the computer is a member of.

    All of the 255s in a subnet mask collectively refer to the

    network portion, whereas the 0s refer to the host portion.

    Type of

    Address

    First Octet Second Octet Third Octet Fourth Octet

    IP Address 192 168 1 1

    Subnet Mask 255 255 255 0

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 40

    Host

    IP addresses are usually applied to your network adapter, but

    they can also be applied to other devices like switches,

    routers, and so on

    The fact that a device or computer has an IP address is what

    makes it a host

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 41

    LAN: Computers and other devices are connected using

    copper-based twisted-pair cables or wireless equipment.

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 42

    Network Topology

    A network topology defines the physical connections of hosts

    in a computer network.

    There are several types of physical topologies including:

    Bus

    Ring

    Star

    Mesh

    Tree

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 43

    Star

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 44

    Mesh

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 45

    Ring

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 46

    Star Topology

    Most Common topology

    Each computer is

    individually wired to a

    central connecting device

    (hub, switch or SOHO

    router) with twisted-pair

    cabling

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 47

    Mesh Topology

    Every computer connects to every other computer; no

    central connecting device is needed.

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 48

    Ring Topology

    In a LAN environment,

    each computer is

    connected to the network

    using a closed loop

    Used by Token Ring and

    Fiber Distributed Data

    Interface (FDDI)

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 49

    Token Ring

    A Token Ring network sends data logically in a ring fashion,

    meaning that a token goes to each computer, one at a time,

    and continues on in cycles

    Namely, all computers in a Token Ring network are

    connected to a central connecting device known as a

    Multistation Access Unit (MAU or MSAU)

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 50

    Ethernet

    Institute of Electrical and Electronics Engineers (IEEE)

    standard (802.3) that defines how information is sent and

    received between network adapters, hubs, switches, and

    other devices

    Ethernet is the de facto standard and is the most widely-

    installed local area network technology

    Common types of Ethernet include:

    802.3u or Fast Ethernet that runs at 100 Mbps

    802.3ab or Gigabit Ethernet

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 51

    Frames

    Computers on Ethernet networks communicate via frames

    A frame is a sequence of bits containing a detectable

    beginning and end of a packet in the stream of bits

    A frame is a data packet residing on Layer 2 of the OSI model

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 52

    Twisted Pair Cable

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 53

    Twisted-Pair Cable

    the most commonly used cable type in local area

    networks

    relatively easy to work with, flexible, efficient, and fast

    contains eight wires grouped into four twisted pairs,

    typically blue, orange, green, and brown

    The twisted wires reduce crosstalk and interference

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 54

    Twisted-Pair Cable with the Wires Exposed

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 55

    568B, 568A, and BOGB standards

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 56

    Twisted Pair Categories

    Twisted-pair cables are categorized according to the

    frequency at which they transmit signals and their data

    transfer rate

    Cable Type Speed

    Category 3 (Cat-3) 10 Mbps

    Category 5 (Cat-5) 100 Mbps

    Category 5e (Cat-5e) 100 Mbps and 1000 Mbps+

    Category 6 (Cat-6) 1000 Mbps+

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 57

    Tools For Twisted Pair Cables

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 58

    Twisted-Pair Patch Cable

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 59

    Types of Patch Cables

    Straight through cable Most common type of patch cable

    Used to connect a computer to a central connecting device like a switch

    Crossover cable Used to direct connect similar devices without the use of a hub

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 60

    Patch Panel and RJ45 Wall Jack

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 61

    Network Documentation

    Network documentation helps describe, define, and explain

    the physical and logical method for connecting devices

    The documentation phase occurs before a network is built,

    or when changes are made to the network

    Microsoft Visio is a tool that can be used to document

    networks

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 62

    Hub

    A Hub is the most basic

    central connecting device

    Hubs enable computers on

    a network to communicate

    A host sends data to the

    hub. The hub sends the data

    to all devices connected to

    the hub

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 63

    Switch

    Switches work the same

    was as a hub, but they can

    identify the intended

    recipient of the data

    Switches can send and

    receive data at the same

    time

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 64

    Router

    Routers enable computers to communicate and allow communication between two networks – such as your home network and the Internet

    This communications link between the one network and the other is where the LAN ends

    192.168.1.1

    Internet

    24.136.72.110

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 65

    3. LAN Architectures

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 66

    Peer-to-Peer Networking

    Peer-to-peer networking distributes applications or

    workloads between computers

    Peers are both service providers and service requestors

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 67

    Client/Server Networking

    The client/server model is an architecture that distributes

    applications between servers and client computers

    Server: System that provides services such as Windows

    Server 2008 R2

    Client: Device that requests services such as Windows 7

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 68

    Distributed Computing

    Distributive computing includes both client-server and peer-

    to-peer networks

    Every device or workstation has its own processing power

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 69

    Centralized Computing

    Computing is done at a central location using terminals that

    are attached to this main system

    Mainframes are a powerful computer and the rest of the

    devices connected to the computer are known as terminals

    (or dumb terminals)

    Each terminal consisted solely of a keyboard and display with

    no processing power

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 70

    Servers

    More powerful computers that provide centralized services:

    File

    Print

    Database

    Network controller

    Messaging/Email

    Web

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 71

    Client and Server Operating Systems

    Client Operating Systems Server Operating Systems

    Windows 8 Windows Server 2012

    Windows 7 Windows Server 2008 R2

    Windows Server 2008

    Windows Vista

    Windows XP

    Windows Server 2003

    Windows 2000 Professional Windows 2000 Server

    Windows NT 4.0 Workstation

    Windows ME/98/95

    Windows NT 4.0 Server

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 72

    Summary of What We Covered in Week2:

    Understand local area networks (LANs), including but not

    limited to LAN elements, design, IP addressing, and LAN

    types

    Understand network topologies , including topologies such

    as star, mesh, and ring; Ethernet architecture; and the client-

    server and peer-to-peer networking models

  • Computer Networks

    -Week2

    Sunday, March 16, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 73

    In Week3 (Next Class) We Will:

    Cover All Important Concepts in Week1 and Week2.

    Explain What you Should know and Remember in Past 2

    weeks.

    DON’T MISS.

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 74

    In Week3 We Will:

    Cover All Important Concepts in Week1 and Week2.

    Explain What you Should know and Remember in Past 2

    weeks.

    Makin LAN Connections(UTP Cable).

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 75

    In Week1:

    Give 3 Examples for the general use of Networks in each of

    the following:

    1. Home.

    2. Work.

    3. Mobile (on the go)

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 76

    Examples are:

    Work:

    – Email, file sharing, printing, …

    Home:

    – Movies / songs, news, calls / video, messaging, e-commerce,

    Mobile:

    – Calls / texts, games, videos, maps, information access …

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 77

    Categorize the following uses of Networks as user

    communication and Resource Sharing:

    VoIP (voice-over-IP) , Sharing Printers, Video conferencing

    Sharing Machines in the cloud, Instant messaging, Content

    Delivery. Social networking, Statistical Multiplexing. ….

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 78

    List 5 Different Types of Networks we use our daily

    life

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 79

    List 5 of these networks…

    WiFi (802.11)

    Enterprise / Ethernet

    ISP (Internet Service Provider)

    Mobile phone / cellular (2G, 3G, 4G)

    Bluetooth

    Telephone

    Satellite ...

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 80

    List 4 Type of Networks by Scale with examples:

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 81

    Define LAN, what are the reasons for building Local Area

    Networks?

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 82

    Reasons include:

    Sharing Resources:

    Example:……………………..

    Communication:

    Examples:………………..

    Organization and User Management:

    Examples:

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 83

    Define each of the Following:

    Server.

    PC.

    Mac.

    Terminal

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 84

    What is most important component(device) in our

    Computers that enables to send and receive data.

    What is the name of the software component, which defines

    how the card will interact with the operating system

    What are the Types of Network adapters.

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 85

    What is the device we should have in order for Wireless

    Devices to Communicate.

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 86

    How data travels in the network cable?

    What is the unit for the data transfer(speed) of the cable?

    Define these types of data transfers:

    Unicast and

    Broadcast.

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 87

    Why we assign IP address to a computer ?

    What makes a device a host?

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 88

    What are the Characteristics of these Network Topologies:

    Ring

    Star

    Mesh

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 89

    What are the 4 Colors(BOGB) of the UTP cable?

    When we should use :

    Straight-through cable

    Cross-over Cable

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 90

    Understand and Define the following:

    Hub

    Switch

    Router

    Peer to Peer Network.

    Client/Server Network.

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 91

    What are the Important Services that Servers Provide?

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 92

    Main Services are

    File

    Print

    Database

    Network controller

    Messaging/Email

    Web

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 93

    List three examples of each :

    Client Operating System

    Server Operating System

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 94

    Making LAN Connections:

    Straight-through and Cross-over UTP Cables:

    Typically, when connecting different types of devices, use a

    straight-through cable. And when connecting the same type

    of device, use a crossover cable.

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 95

    Straight-through UTP Cables

    A straight-through cable has connectors on each end that are

    terminated the same in accordance with either the T568A or

    T568B standards.

    Use straight-through cables for the following connections:

    Switch to a router Ethernet port

    Computer to switch

    Computer to hub

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 96

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 97

    Crossover UTP Cables

    To achieve this type of connection with a UTP cable, one end must be terminated as T568A pinout, and the other end terminated with T568B pinout,

    To summarize, crossover cables directly connect the following devices on a LAN:

    Switch to switch

    Switch to hub

    Hub to hub

    Router to router Ethernet port connection

    Computer to computer

    Computer to a router Ethernet port

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 98

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 99

    Build Straight-through and Cross-over Cable UTP

    cables.

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 100

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 101

  • Computer Networks

    -Week3

    Sunday, March 23, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 102

  • Computer Networks

    -Week4-8

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 103

    In these Weeks:

    1. Standards.

    2. OSI and TCP/IP Models

    3. Understanding Internet Protocol & TCP/IP Tools

    4. Network Services and Wide Area Networks

    5. Network Infrastructure and Security

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 104

    Standards

    Standards are sets of rules that ensure hardware and software

    released from different companies work together

    Examples of Organizations that Coordinate Standards:

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 105

    Examples of Organizations that Coordinate Standards:

    International Organization for Standardization (ISO) – Federation of standards organizations from multiple nations

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 106

    Open Systems Interconnection (OSI)

    The Open Systems Interconnection (OSI) reference model is used to define

    how data communication occurs between devices

    The model is divided into 7 layers, each layer providing services to the layers

    above and below

    Layer Defines Layer 7 – Application Layer Enables users and applications to access network services

    Layer 6 – Presentation Layer Translates data into a common format

    Layer 5 – Session Layer Establishes a communication session between devices

    Layer 4 – Transport Layer Manages message fragmentation and reassembly

    Layer 3 – Network Layer Manages data routing and creating sub networks

    Layer 2 – Data Link Layer Provides error-free transfer of data frames

    Layer 1 – Physical Layer Physical network media and signal methods

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 107

    OSI Model Layers

    Layer Protocol Data

    Unit (PDU)

    Application Data

    Presentation Data

    Session Data

    Transport Segment

    Network Packet

    Data Link Frame

    Physical Bits

    Layer Protocol Data

    Unit (PDU)

    Application Data

    Presentation Data

    Session Data

    Transport Segment

    Network Packet

    Data Link Frame

    Physical Bits

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 108

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 109

    OSI and TCP/IP MODEL

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 110

    OSI Model and Data Packet Units

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 111

    OSI , TCP Models and Protocols

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 112

    The two Groups of OSI Layers

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 113

    The lower layers

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 114

    The Transport layer can provide connection orientation

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 115

    Transport Layer Protocols (TCP and UDP)

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 116

    User Datagram Protocol (UDP)

    Applications that use UDP include:

    Domain Name System (DNS)

    Video Streaming

    Voice over IP (VoIP)

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 117

    Transmission Control Protocol (TCP)

    Applications that use TCP are:

    Web Browsers

    E-mail

    File Transfers

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 118

    LAYERS OF NETWORK COMMUNICATION

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 119

    Port Addressing

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 120

    The Internet Assigned Numbers Authority (IANA) assigns

    port numbers

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 121

    TCP Ports

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 122

    UDP Ports

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 123

    TCP/UDP Common Ports

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 124

    Three-way handshake Process:

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 125

    Windowing

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 126

    Layer 7 – Application Layer

    Serves as a the window for users and application processes to

    access network services

    This layer is where message creation begins

    End-user protocols such as FTP, SMTP, Telnet, and RAS work

    at this layer

    This layer is not the application itself, but the protocols that

    are initiated by this layer

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 127

    Layer 6 – Presentation Layer

    This layer translates the data format from sender to receiver

    in the various OSes that may be used

    Presentation Layer concepts include: character code

    conversion, data compression, and data encryption

    Redirectors work on this layer, such as mapped network

    drives that enable a computer to access file shares on a

    remote computer

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 128

    Layer 5 – Session Layer

    The Session Layer manages session establishment,

    maintenance and termination between network devices

    Example: when you log on and log off

    This layer controls the name and address database for the OS

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 129

    Layer 4 – Transport Layer

    This layer ensures messages are delivered error-free, in

    sequence and with no losses or duplications

    Protocols that work at this layer segment messages, ensure

    correct reassembly at the receiving end, perform message

    acknowledgement and message traffic control

    The Transport Layer contains both connection-oriented and

    connectionless protocols.

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 130

    Connection Oriented Communications:

    Require both devices involved in the communication

    establish an end-to-end logical connection before data can be

    sent

    These communications are considered reliable network

    services

    Packets not received by the destination device can be resent

    by the sender

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 131

    Hello! I am a

    PCHello! I am a

    Server!

    Ok, I will

    watch for it!

    I want to send

    you something

    important!

    Connection Oriented Communications:

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 132

    Layer 3 – Network Layer

    Controls the operations of routing and switching information

    to different networks

    Translates logical addresses or names to physical addresses

    Internet Protocol (IP) is a Network Layer protocol

    Devices that work at the network layer are routers and IP

    switches

    Network Layer components: IP addresses, subnets

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 133

    Packets

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 134

    Layer 2 – Data Link Layer

    Establishes, maintains, and decides how transfer is

    accomplished over the physical layer and ensures error-free

    transmission over the physical layer

    Physical addresses (the hexadecimal address that is burned

    into the ROM of the NIC), known as the MAC address

    uniquely identify each hardware device work at the Data Link

    Layer

    Data Link Layer components: network interface cards and

    bridges

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 135

    Layer 2 Switches

    Layer 2 switches are hardware-based and use the MAC

    address of each host computer’s network adapter when

    deciding where to direct data frames

    Ports on the switch are mapped to the specific MAC address

    of the device attached

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 136

    Media Access Control Address

    Network adapters on an Ethernet network have unique

    Media Access Control (MAC) addresses

    MAC addresses are unique identifiers assigned to network

    adapters by the manufacturer

    MAC address is written in hexadecimal

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 137

    Layer 1 – Physical Layer

    Defines the physical and electrical medium for data transfer

    Physical layer components: cables, jacks, patch panels, punch

    blocks, hubs…

    Physical layer concepts: topologies, analog versus

    digital/encoding, bit synchronization, baseband versus

    broadband, multiplexing, and serial data transfer

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 138

    Ethernet Standards

    LAN standard providing a communication method for high speed data exchange among devices

    Defined Physical and Data Link Layer

    100BASE-T 100 for 100 Mbps BASE for baseband T for twisted-pair cabling

    Baseband refers to the fact that devices on the network use digital signaling over a single frequency

    Broadband systems use analog signaling over a range of frequencies enabling multiple channels over the same physical medium

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 139

    Communications Subnetwork:

    The communications subnetwork consists of layers 1 through

    3

    Physical

    Data Link

    Network

    Regardless of what type of data transmission occurs in a

    computer network, the communication subnetwork is used

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 140

    3. Understanding Internet Protocol & TCP/IP

    Tools

    IPV4

    Internet Protocol version 4 (IPv4) is the fourth version

    of the Internet Protocol and the first version to be

    widely deployed

    IPv4 is a frequently used communications protocol and is

    one of the core protocols for the Internet

    IP resides on the network layer of the OSI model

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 141

    IP Addresses

    IP addresses consist of four octets (8-bits), each between 0 and

    255.

    Examples include:

    12.5.24.2

    127.0.0.1

    192.168.3.54

    208.32.56.232

    In order for an IP address to function, there must be a properly

    configured IP address and compatible subnet mask

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 142

    Classful Network Architecture

    The IPv4 classification system is known as a classful network

    architecture broken down into five sections: Classes A, B, and C

    are commonly used

    An Class A IP address, the first octet is the “network” portion

    Class IP Range (1st Octet)

    Default Subnet

    Mask

    Network ID / Host ID

    A 0 – 127 255.0.0.0 Net.Host.Host.Host

    B 128 - 191 255.255.0.0 Net.Net.Host.Host

    C 192 – 223 255.255.255.0 Net.Net.Net.Host

    D 224 - 239 N/A N/A

    E 240 - 255 N/A N/A

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 143

    Loopback Testing

    The range for Class A is 0–127

    The 127 network number isn’t used by hosts as a logical IP address

    Instead, this network is used for loopback IP addresses, allowing

    for testing

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 144

    Usable Addresses

    The first and last addresses cannot be used

    For network 172.24.3.X

    The 0 (in binary) for the host address is the entire network

    172.24.3.0

    The 1s (in binary) for the host address is the broadcast address

    172.24.3.255

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 145

    IP Conflict

    IP conflicts occur when two devices have been assigned the same

    IP address

    Windows Error:

    There is an IP address conflict with another system on the

    network

    If there is an IP address conflict, the devices will have problems

    sending and receiving data

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 146

    Public and Private Addresses

    IPv4 addresses are further classified as either public or private.

    Public IP addresses are ones that are exposed to the Internet

    Devices connected to the Internet can potentially communicate

    with them

    Private IP addresses are hidden from the Internet and any other

    networks

    Usually behind an IP proxy or firewall device

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 147

    Static and Dynamic Addresses

    Static IP address are addresses that are manually assigned to a host

    Dynamic IP addresses are more common than static IP addresses,

    whereas they automatically obtain an IP address (and other IP

    information)

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 148

    Common TCP/IP Tools

    command prompt

    ipconfig

    ping

    Tracert

    Netstat

    Pathping

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 149

    Command Prompt

    The Windows command prompt is Microsoft’s version of a

    command-line interface or CLI

    Running the command prompt as an Administrator is also known

    as running it in elevated mode

    Tools can be run using the command prompt

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 150

    Ipconfig

    Displays the current configuration of the installed IP stack on

    a networked computer using TCP/IP

    The /all switch can be used to view additional details about

    each adapter

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 151

    Ping

    verifies IP-level connectivity to another TCP/IP device by

    sending Internet Control Message Protocol (ICMP) Echo

    Request messages

    A number of switches can accommodate different testing

    scenarios

    Can be used to test IPv4 and IPv6 connectivity

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 152

    Ping Process

    Hey, are you awake?

    Why yes, yes I am...

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 153

    Tracert

    Determines the path taken to a destination by sending

    Internet Control Message Protocol (ICMP) Echo Request

    messages to the destination with incrementally increasing

    Time to Live (TTL) field values

    Used to “trace” a network path from sending to receiving

    device

    Useful if the local device is testing ok but connectivity can’t

    be established

  • Computer Networks

    -Week4

    Wednesday, March 26, 2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 154

    Tracert in Action

    Hey, how do I get

    there?

    First you go

    through me...Second you go

    through me...

    Then you re here!

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 155

    4. Network Services and Wide Area Networks

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 156

    DNS

    Domain Name System (DNS) is a worldwide service that

    resolves host names to IP addresses

    DNS is part of the application layer of the TCP/IP reference

    model

    DNS servers use port 53 to accept name resolution requests

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 157

    DHCP

    Dynamic Host Configuration Protocol (DHCP) is a

    client/server protocol that enables configured client

    computers to obtain IP addresses automatically.

    The IP information obtained might include the following:

    IP addresses

    Subnet masks

    Gateway addresses

    DNS server addresses

    Other advanced options

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 158

    The DHCP Server service provides the following

    benefits:

    Reliable IP address configuration

    Reduced network administration

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 159

    DHCP Server

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 160

    How Does DHCP Server Word?

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 161

    Wide Area Networks (WAN)

    Wide area networks (WANs) connect multiple local area networks together

    WANs connect multiple LANs that can include a home, school, or buildings

    WANs enable network to function without concern to a location

    WAN technologies can include:

    Packet Switching: Devices transport packets via shared links

    Leased Line: Dedicated point to point connection

    Circuit Switching: Dedicated circuit path is created between end points (dial up)

    ISDN, DSL, Broadband Cable, POTS/PSTN….

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 162

    Routing

    Routing is the process of managing the flow of data between

    network segments and between hosts or routers

    Data is sent along a path according to the IP networks and

    individual IP addresses of the hosts

    A router is a network device that maintains tables of information

    about other routers on the network or internetwork

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 163

    Static and Dynamic Routing:

    A static route is a path that is manually configured and remains

    constant throughout the router’s operation

    A dynamic route is a path that is generated dynamically by using

    special routing protocols

  • Computer Networks

    -Week4-8

    Wednesday, March 5,2014 Computer Networks: STS/MTA/Coursera/Cisco

    Instructor: Ahmed Hussein Farah 164

    WAN Technologies:

    Integrated Services Digital Network (ISDN) is a set of

    communication standards enabling simultaneous digital

    transmission of data, fax, voice and video .

    ISDN can be broken down into two major categories:

    Basic rate ISDN (BRI):

    Primary rate ISDN (PRI):

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    DSL

    Digital subscriber line (DSL) is a family of technologies that

    provides data transmissions over local telephone networks

    DSL allows for voice and data to be run over the same line

    DSL uses higher frequency bands to transmit data

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    Broadband Cable:

    Broadband cable is used for cable Internet and cable television

    using the cable television network

    It operates at a higher speed than DSL and rates can range from

    384 kbps to 20 Mbps +

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    POTS/PSTN

    POTS/PSTN stands for plain old telephone system/public

    switched telephone network.

    This is what we use now for “regular” phone lines, and it has been

    around since the 1940s.

    POTS/PSTN is now digital at the switching office and some

    central offices, but there analog lines run to people’s homes.

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    5. Network Infrastructure and Security

    Internet

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    Internet

    The Internet is a worldwide system of connected computer

    networks

    Devices that connect to the Internet use the TCP/IP protocol

    suite

    The Internet contains a lot of information, resources and services:

    World Wide Web (WWW) servers hosting content

    Supporting infrastructure for email

    Connectivity for peer-to-peer networks

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    World Wide Web

    The World Wide Web (WWW) is an enormous system of

    interlinked hypertext documents that can be accessed by using a

    web browser

    Interlinked hypertext documents can contain text, graphics and

    videos

    Currently, the World Wide Web is in a stage known as Web 2.0

    Web 2.0 is an interactive type of web experience compared to the

    previous version 1.0

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    An intranet is a private computer network or single Web site that

    an organization implements in order to share data with employees

    around the world

    User authentication is necessary before a person can access the

    information in an intranet

    Ideally, this keeps the general public out, as long as the intranet

    is properly secured

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    Accessing Company Data

    A company can present information to different groups:

    Intranet – For internal employees

    Extranet – For partners

    Web Server – For the public

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    Partner Public Remote Users

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    VPN

    A virtual private network (VPN) is a connection between two or

    more computers or devices that are not on the same private

    network

    In order to ensure that only the proper users and data sessions

    cross to a VPN device, data encapsulation and encryption are used

    A “tunnel’ is created, through the LANs and WANs that are being

    used

    /ISP

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    Firewalls

    Firewalls are used to help protect a network from malicious attack

    and unwanted intrusion

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    END OF THE COURSE:

    Summary

    Concepts you Should Know and Understand.