Introduction To Networking
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Introduction To Networking Introduction To Networking Presentation Transcript

  • Introduction to Networking STBS 2201 By Norrima Mokhtar
  • STBS 2201: Pengenalan Kepada Networking
    • Tajuk:
      • Introduction to NetworkingNetworking: The Big PictureTelecommunications Components of The Big PictureISO/OSI
      • Breaking Up the Big Picture!The Local LoopLocal Area Networks (LANS)MANsWANs
  • Tajuk:
      • Transmission Media - Guided
      • Open Wire
      • Twisted Pair
      • Unshielded Twisted Pair
      • Coaxial Cable
      • Optical fiber
      • Optical Transmission Modes
      • Step Index Mode
      • Graded Index Mode
      • Single Mode
      • Advantages of Optical Fiber:
      • Disadvantages of optical fiber:
      • Media versus Bandwidth
      • Transmission Media - Unguided
    View slide
  • Tajuk:
    • Introduction to TCP/IPLink
    • Introduction to the services.
    • Network Interface Cards
    • Repeaters
    • Hubs
    • Bridges
    • Routers
    • Gateways
    • And is good if this will be added.
      • Domain Name Service
      • FTP Service
      • HTTP service And others services provided.
    View slide
  • Data Communications
    • Is transfer of data or information between a source and a receiver.
    • The source transmits the data and the receiver receives it. Data Communication is interested in the transfer of data, the method of transfer and the preservation of the data during the transfer process.
    • The purpose of data communications is to provide the rules and regulations that allow computers with different disk operating systems, languages, cabling and locations to share resources.
    • The rules and regulations are called protocols and standards in data communications.
  • Definition of NETWORK
    • A network is a set of hardware devices connected together, either physically or logically to allow them to exchange information
    • When two or more computers are connected together, they are in a network. The practice of connecting these computers together is called networking.
    • A network may contain two or more computers that are linked to share resources, files, and / or to communicate. To achieve communicating, commuters on a network must have a common protocol.
    • Different organizations and institutions require different types of network infrastructure, protocols and applications. This will depend on the size of the organization, the level of security required, the  type of business, level of administrative support available,  the amount of network traffic, needs of the network users the network budget.
    • The type of network used will determine its size and the number of computers connected as well as the physical distance that could be covered by the network.
  • What does networking have to do with telephones?
    • Telephones and networking work hand in hand.
    • The telecommunications industry has been gradually integrating with the computer industry and the computer industry has been gradually integrating with the telecommunications industry.
    • The common goal is to join distantly located Local Area Networks into Metropolitan and Wide Area Networks (MANs and WANs).
  • Voice Channels
    • When we think of telecommunications, the first thing that comes to mind is telephone systems and the phone at home.
    • Talking to someone on the phone uses voice channels.
    • Voice Channel: Dial-up connection through a modem using standard telephone lines.
    • Typical voice channel communication rates are: 300, 1200, 2400, 9600, 14.4k, 19.2k, 28.8k, 33.6k and 56 kbps (bits per second).
  • Data Channels
    • Data channels are dedicated lines for communicating digitized voice and data.
    • At the end of 1996, there was a major milestone when more data was communicated in North America's telecommunications system than voice.
    • Data Channels are special communications channels provided by "common carriers" such as Telus, Sprint, Bell Canada, AT&T, etc. for transferring digital data.
    • Data Channels are also called "Leased Lines". They are "directly" connected: you don't have to dial a connection number. The connections are up and running 24 hours per day. They appear to work as if there were a wire running directly between the source and the destination. Typical transfer rates for data channels are: 56 k, 128k, 1.544 M, 2.08 M, 45M and 155 Mbps. (In Malaysia depends on package offer by service provider such as TMNET)
  • Data Channels
    • Common carriers charge for data connections by:
    • The amount of data transferred (megabytes per month)
    • The transfer rate (bits per second)
    • The amount of use (time per month)
  • Applications
    • Networks are used for an incredible array of different purposes. In fact, the definitions above are so simple for the specific reason that networks can be used so broadly, and can allow such a wide variety of tasks to be accomplished. While most people learning about networking focus on the interconnection of PCs and other “true” computers, actually we use various types of networks every day.
  • Networking: The Big Picture
  • Telecommunications Components of The Big Picture
    • ISDN ­ Integrated Services Digital Network
    • Private Branch Exchanges ­ PBXs, Key Systems
    • Telcos ­ AT&T, Bell Telephone, Sprint, Telus
    • DataPac & DataRoute ­ Packet switching and analog switching WAN protocols
    • Cell Relay ­ Digital packet switching WAN protocol
    • Frame Relay ­ Digital packet switching WAN protocol
    • X.25 ­ Analog packet switching WAN protocol
    • ATM ­ Asynchronous Transfer Mode WAN protocol
    • World Wide Web ­ Hypertext-based multimedia system
    • ADSL ­ Asymmetrical Digital Subscriber Line
  • Applications
    • Example:
    • Each time you pick up a phone
    • Use a credit card at a store
    • Get cash from an ATM machine
    • Even plug in an electrical appliance
    • we are using some type of network.
  • Computer Networks
    • A is a set of independent computer systems interconnected by telecommunication links.
  • The Advantages (Benefits) of Networking
    • Connectivity and Communication
    • Data Sharing
    • Hardware Sharing
    • Internet Access
    • Internet Access Sharing
    • Data Security and Management
    • Performance Enhancement and Balancing
    • Entertainment
  • Connectivity and communication:
    • Networks connect computers and the users of those computers. Individuals within a building or work group can be connected into local area networks (LANs) ; LANs in distant locations can be interconnected into larger wide area networks (WANs) .
    • Once connected, it is possible for network users to communicate with each other using technologies such as electronic mail. This makes the transmission of business (or non-business) information easier, more efficient and less expensive than it would be without the network.
  • Data Sharing
    • One of the most important uses of networking is to allow the sharing of data. Before networking was common, an accounting employee who wanted to prepare a report for her manager would have to produce it on his PC, put it on a floppy disk, and then walk it over to the manager, who would transfer the data to her PC's hard disk.
    • True networking allows thousands of employees to share data much more easily and quickly than this. More so, it makes possible applications that rely on the ability of many people to access and share the same data, such as databases.
  • Hardware Sharing
    • Networks facilitate the sharing of hardware devices.
    • For example, instead of giving each of 10 employees in a department an expensive color printer, one printer can be placed on the network for everyone to share.
  • Internet Access:
    • The Internet is itself an enormous network, so whenever you access the Internet, you are using a network.
    • The significance of the Internet on modern society is hard to exaggerate, especially for those of us in technical fields.
  • Internet Access Sharing
    • Small computer networks allow multiple users to share a single Internet connection.
    • Special hardware devices allow the bandwidth of the connection to be easily allocated to various individuals as they need it, and permit an organization to purchase one high-speed connection instead of many slower ones.
  • Data Security and Management
    • In a business environment, a network allows the administrators to much better manage the company's critical data. Instead of having this data spread over dozens or even hundreds of small computers in a haphazard fashion as their users create it, data can be centralized on shared servers.
    • This makes it easy for everyone to find the data, makes it possible for the administrators to ensure that the data is regularly backed up, and also allows for the implementation of security measures to control who can read or change various pieces of critical information.
  • Performance Enhancement and Balancing
    • Under some circumstances, a network can be used to enhance the overall performance of some applications by distributing the computation tasks to various computers on the network.
  • Entertainment
    • Networks facilitate many types of games and entertainment. The Internet itself offers many sources of entertainment, of course.
    • In addition, many multi-player games exist that operate over a local area network. Many home networks are set up for this reason, and gaming across wide area networks (including the Internet) has also become quite popular.
    • Of course, if you are running a business and have easily-amused employees, you might insist that this is really a disadvantage of networking and not an advantage!
  • The Disadvantages (Costs) of Networking
    • Network Hardware, Software and Setup Costs
    • Hardware and Software Management and Administration Costs
    • Undesirable Sharing
    • Data Security Concerns
  • Network Hardware, Software and Setup Costs
    • Computers don't just magically network themselves, of course. Setting up a network requires an investment in hardware and software, as well as funds for planning, designing and implementing the network.
    • For a home with a small network of two or three PCs, this is relatively inexpensive, possibly amounting to less than a hundred dollars with today's low prices for network hardware, and operating systems already designed for networks.
    • For a large company, cost can easily run into tens of thousands of RM or more.
  • Hardware and Software Management and Administration Costs
    • In all but the smallest of implementations, ongoing maintenance and management of the network requires the care and attention of an IT professional.
    • In a smaller organization that already has a system administrator, a network may fall within this person's job responsibilities, but it will take time away from other tasks.
    • In more substantial organizations, a network administrator may need to be hired, and in large companies an entire department may be necessary.
  • Undesirable Sharing
    • With the good comes the bad; while networking allows the easy sharing of useful information, it also allows the sharing of undesirable data.
    • One significant “sharing problem” in this regard has to do with viruses, which are easily spread over networks and the Internet.
    • Mitigating these effects costs more time, money and administrative effort.
  • Illegal or Undesirable Behavior
    • Similar to the point above, networking facilitates useful connectivity and communication, but also brings difficulties with it.
    • Typical problems include abuse of company resources, distractions that reduce productivity, downloading of illegal or illicit materials, and even software piracy.
    • In larger organizations, these issues must be managed through explicit policies and monitoring, which again, further increases management costs.
  • Data Security Concerns
    • If a network is implemented properly, it is possible to greatly improve the security of important data.
    • In contrast, a poorly-secured network puts critical data at risk, exposing it to the potential problems associated with hackers, unauthorized access and even sabotage.
  • Networking is worthwhile
    • Most of these costs and potential problems can be managed; that's a big part of the job of those who set up and run networks.
    • In the end, as with any other decision, whether to network or not is a matter of weighing the advantages against the disadvantages.
    • Of course today, nearly everyone decides that networking is worthwhile.
  • Networking is worthwhile
    • Networking has a few drawbacks that balance against its many positive aspects. Setting up a network has costs in hardware, software, maintenance and administration.
    • It is also necessary to manage a network to keep it running smoothly, and to address possible misuse or abuse.
    • Data security also becomes a much bigger concern when computers are connected together.
        • Compatible interconnection of network devices is fundamental to reliable network communications. Developing a set of standards that equipment manufacturers could adhere to went a long way towards providing an open environment for network communications.
    • In the late 1970s the International Organization for Standardization (ISO) worked on a seven layer model for LAN architectures by defining the Open Systems Interconnection Basic Reference Model (OSI).
    • Alongside this The ISO developed a set of protocols that fit within this model.
    • Since then, other models such as the 5 layer TCP( Transmission Control Protocol ) /IP model were developed, however the OSI model is still used to map and categorise protocols because of its concise and clear way of representing network functions.
  • These are the 7 Layers of the OSI model:
    • 7. Application Layer (Top Layer)
    • 6. Presentation Layer
    • 5. Session Layer
    • 4. Transport Layer
    • 3. Network Layer
    • 2. Data Link Layer
    • 1. Physical Layer (Bottom Layer)
  • Application Layer 7
    • The application layer defines the interfaces for communication and data transfer.
    • This layer also provides and support services such as job transfer, handles network access, e-mail, supports user applications and error recovery.
  • Application Layer 7
    • Examples of services within the application layer include:
    • FTP (File Transfer Protocol),
    • DNS
      • (The Domain Name System (abbreviated DNS) is an Internet directory service )
    • SNMP
      • Simple Network Management Protocol (SNMP)
    • SMTP gateways
      • Simple Mail Transfer Protocol (SMTP)
    • Web browser
    • Network File System (NFS)
    • Telnet and Remote Login (rlogin)
    • Database software
    • Print Server Software
  • Presentation Layer 6
    • This provides function call exchange between host operating systems and software layers. It defines the format of data being sent and any encryption that may be used, and makes it presentable to the Application layer.
    • Examples of services used are listed below:
    • MIDI
      • MIDI (Musical Instrument Digital Interface) is an industry-standard protocol that enables electronic musical instruments, computers and other equipment to communicate, control and synchronize with each other.
    • HTML
      • Hypertext Markup Language, is the predominant markup language for web pages.
  • Presentation Layer 6
    • Examples of services used are listed below:
    • GIF
      • The Graphics Interchange Format (GIF) is an 8-bit-per-pixel bitmap image format.
    • TIFF
      • Tagged Image File Format (abbreviated TIFF) is a container format for storing images
    • JPEG
      • JPEG stands for Joint Photographic Experts Group, the name of the committee that created the standard
      • is a commonly used method of compression for photographic images.
  • Session Layer 5
    • Session layer establish and manages the session between the two users at different ends in a network.
    • Session layer also manages who can transfer the data in a certain amount of time and for how long.
    • The examples of session layers and the interactive logins and file transfer sessions.
    • Session layer reconnect the session if it disconnects.
    • It also reports and logs and upper layer errors.
  • Session Layer 5
    • Examples of Session layer protocols are listed below:
      • RPC
        • Remote procedure call, a protocol that allows a computer program running on one host to cause code to be executed on another host
      • SQL
        • Structured Query Language.
        • SQL is a standard interactive and programming language for getting information from and updating a database.
      • NetBIOS names
        • The NetBIOS allows applications on separate computers to communicate over a local area network
  • Transport Layer 4
    • Transport layer manages end to end message delivery in a network and also provides the error checking and hence guarantees that no duplication or errors are occurring in the data transfers across the network.
    • Transport layer also provides the acknowledgement of the successful data transmission and retransmits the data if no error free data was transferred.
    • It also provides and error handling and connectionless oriented data deliver in the network.
  • Transport Layer 4
    • Examples are:
      • TCP
        • The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite.
      • UDP
        • User Datagram Protocol (UDP) is one of the core protocols of the Internet protocol suite.
      • SPX
        • IPX/SPX stands for Internetwork Packet Exchange/Sequenced Packet Exchange. It is a networking protocol used by the Novell NetWare operating systems. Like UDP, IPX is a datagram protocol used for connectionless communications.
  • Network Layer 3
    • The network layer determines that how data transmits between the network devices.
    • It also translates the logical address into the physical address e.g computer name into MAC address.
    • It is also responsible for defining the route, managing the network problems and addressing.
    • Router works on the network layer and if a sending device does not break the data into the similar packets as the receiving device then network layer split the data into the smaller units and at the receiving end the network layer reassemble the data.
  • Network Layer 3
    • Examples of Layer 3 protocols include:
      • IP
        • (Internet Protocol address), a computer network address
      • IPX
        • Internetwork Packet Exchange ( IPX
      • DECnet
        • DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers.
  • Data Link Layer 2
    • Defines procedures for operating the communication links
    • Frames packets Detects and corrects packets transmit errors
    • Protocols:
      • Logical Link Control
      • error correction and flow control
      • manages link control
  • Data Link Layer 2
    • Examples include:
      • IEEE 802.2
        • IEEE 802.2 is the IEEE 802 standard defining Logical Link Control (LLC), which is the upper portion of the data link layer for local area networks.
      • IEEE 802.3
        • IEEE 802.3 is a collection of IEEE standards defining the physical layer, and the media access control (MAC) sublayer of the data link layer, of wired Ethernet. This is generally a LAN technology with some WAN applications.
      • 802.5 - Token Ring
        • Token ring local area network (LAN) technology
  • Data Link Layer 2
      • Examples include:
      • HDLC
        • High-Level Data Link Control (HDLC) is a bit-oriented synchronous data link layer protocol developed by the International Organization for Standardization (ISO).
      • Frame Relay
        • frame relay consists of an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points.
  • Data Link Layer 2
      • Examples include:
      • FDDI
        • Fiber distributed data interface (FDDI) provides a standard for data transmission in a local area network that can extend in range up to 200 kilometers (124 miles).
      • ATM
        • Asynchronous Transfer Mode, a telecommunications protocol used in networking
  • Data Link Layer 2
    • The Data link layer performs the error check using the Frame Check Sequence (FCS) in the trailer and discards the frame if an error is detected.
    • It then looks at the addresses to see if it needs to process the rest of the frame itself or whether to pass it on to another host.
    • The data between the header and the trailer is passed to layer 3.
    • The MAC( Media Access Control ) layer concerns itself with the access control method and determines how use of the physical transmission is controlled and provides the token ring protocols that define how a token ring operates.
    • The LLC shields the higher level layers from concerns with the specific LAN implementation.
  • Physical Layer 1
    • Physical layer defines and cables, network cards and physical aspects.
    • It defines raw bit stream on the physical media. It also provides the interface between network and network communication devices.
    • It is also responsible for how many volts for 0 and how many for 1.
    • Physical layer also checks the number of bits transmitted per second and two ways or one way transmission.
    • Physical layer also dealing with the optical, mechanical and electrical features.
      • Network Devices: Hubs, Repeaters,
  • Physical Layer 1
    • Examples of specifications include:
    • FDDI
    • 802.3
    • 802.5
    • Ethernet
      • Ethernet is a family of frame-based computer networking technologies for local area networks (LANs).
    • RJ45
      • A registered jack (RJ) is a standardized physical interface for connecting telecommunications equipment (commonly, a telephone jack) or computer networking equipment. The standard designs for these connectors and their wiring are named RJ11, RJ14, RJ45, etc.
  • Tutorial
    • What is Network?
    • What are the advantages of Network?
    • What are the disadvantages of Network?
    • What is ISO?
    • What is OSI?
    • Describe the OSI model.