PPT 09


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PPT 09

  1. 1. CIS105 Networking: Computer Connections
  2. 2. <ul><li>Describe the basic components of a network. </li></ul><ul><li>Explain the methods of data transmission, including types of signals. </li></ul><ul><li>List communication equipment and channels options. </li></ul><ul><li>Describe various network topologies. </li></ul><ul><li>Define firewall and communication protocols. </li></ul>
  3. 3. <ul><li>A Computer Network is two or more computers connected together with data communications equipment over a communications channel/media. </li></ul><ul><li>Benefits of Networks? </li></ul><ul><ul><li>Reduce costs by sharing hardware, software, and data (information). </li></ul></ul><ul><ul><li>Communication! </li></ul></ul>
  4. 4. Initiates instruction Converts data Signal path Converts data Receives Instruction
  5. 5. <ul><li>Modem – modulator -demodulator </li></ul><ul><ul><li>Converts digital signal to analog and vice versa </li></ul></ul><ul><li>Telephone Dialup Modem (56 Kbps) </li></ul><ul><li>DSL (Digital Subscriber Line) Modem </li></ul><ul><li>Cable Modem (cable companies) </li></ul><ul><li>Cellular Modem (uses cellular system) </li></ul><ul><li>Network Integrated w/ Motherboard </li></ul><ul><li>Network Interface Card (NIC) </li></ul><ul><ul><li>Installed in expansion slot </li></ul></ul><ul><ul><li>Wired or wireless cards </li></ul></ul>
  6. 6. <ul><li>Twisted Pair (TP) Cable </li></ul><ul><ul><li>Shielded (STP) </li></ul></ul><ul><ul><li>Unshielded (UTP) </li></ul></ul><ul><ul><li>Ethernet uses RJ45 </li></ul></ul><ul><ul><li>Telephone uses RJ11 </li></ul></ul><ul><ul><li>RJ – Registered Jack </li></ul></ul><ul><li>Coaxial Cable (coax) </li></ul><ul><ul><li>Copper + 3 layers of insulation </li></ul></ul><ul><li>Fiber Optic Cable </li></ul><ul><ul><li>Glass/plastic – uses light to transmit </li></ul></ul><ul><ul><li>Speed of light </li></ul></ul><ul><ul><li>Tubes are insulated </li></ul></ul><ul><li>Wireless (next slide) </li></ul> Physical Media
  7. 7. <ul><li>Wireless </li></ul><ul><ul><li>Generally slower </li></ul></ul><ul><ul><li>Susceptible to interference </li></ul></ul><ul><ul><li>Wi-Fi – Wireless Fidelity – standard 802.11 MIMO ( Multiple-in, Multiple-Out ) </li></ul></ul><ul><ul><li>Infrared </li></ul></ul><ul><ul><li>Bluetooth (see page 205) </li></ul></ul><ul><ul><li>Cellular Radio </li></ul></ul><ul><li>Microwave (line of site) </li></ul><ul><li>Satellite – placed about 22,300 miles above </li></ul>Wireless Media
  8. 8. <ul><li>Bandwidth – is the measurement of how much information can be transmitted over a medium over a prescribed period of time. </li></ul><ul><li>Signal Type </li></ul><ul><ul><li>Analog (continuous signal for older media). </li></ul></ul><ul><ul><li>Digital (individual electrical pulses - binary). </li></ul></ul><ul><li>Broadband transmission– multiple signals simultaneously in both directions - shared line - (Internet connections). </li></ul><ul><li>Baseband transmission – one signal at a time. </li></ul><ul><ul><li>Simplex – data is transmitted one direction only (TV). </li></ul></ul><ul><ul><li>Half-duplex – data is transmitted in both directions, but not at the same time (CB Radio, ATM, FAX). </li></ul></ul><ul><ul><li>Full-duplex – data is transmitted in both directions at the same time for same device (telephone, modem dial-up service). </li></ul></ul>
  9. 9. <ul><li>Asynchronous – start/stop signals for each message. </li></ul><ul><ul><li>Message is usually one or two bytes long. </li></ul></ul><ul><ul><li>Low-speed communication </li></ul></ul><ul><li>Synchronous – larger block of characters are transmitted together. </li></ul><ul><ul><li>Includes error-check bits at the end of the message. </li></ul></ul><ul><ul><li>More complex and more expensive. </li></ul></ul>
  10. 10. <ul><li>A LAN is a collection of computers connected together to share hardware, software, and data. </li></ul><ul><li>LAN Hardware </li></ul><ul><ul><li>Communications equipment / devices </li></ul></ul><ul><ul><li>Communications channel / media </li></ul></ul><ul><ul><li>Hub – connects computers to create a LAN </li></ul></ul><ul><ul><li>Bridges and Routers – connects LANS that use the same protocol </li></ul></ul><ul><ul><li>Gateways – connects LANS that use different protocols, and also serve as routers. </li></ul></ul>
  11. 11.
  12. 12. <ul><li>Node - each computer, printer, or server on network </li></ul><ul><li>Network Topology is the physical layout of a network. </li></ul><ul><li>Three common topologies </li></ul><ul><ul><li>Star </li></ul></ul><ul><ul><li>Ring </li></ul></ul><ul><ul><li>Bus </li></ul></ul><ul><ul><li>See next slide </li></ul></ul>Ring Network Star Network Bus Network
  13. 13. <ul><li>Star </li></ul><ul><ul><li>Server is in center with attached clients </li></ul></ul><ul><ul><li>If server goes down, network goes down </li></ul></ul><ul><ul><li>Easy to expand </li></ul></ul><ul><ul><li>Server controls collisions </li></ul></ul><ul><li>Ring </li></ul><ul><ul><li>All computers connected by a single line </li></ul></ul><ul><ul><li>If any computer goes down, the network goes down </li></ul></ul><ul><ul><li>Difficult to expand </li></ul></ul><ul><ul><li>No collisions, because token travels around one way </li></ul></ul><ul><li>Bus </li></ul><ul><ul><li>All nodes share a single line </li></ul></ul><ul><ul><li>If a computer goes down, the network is still up </li></ul></ul><ul><ul><li>Easy to expand </li></ul></ul><ul><ul><li>Many collisions – causes resend – Terminator’s located at ends. </li></ul></ul>
  14. 14. <ul><li>Connecting two or more LAN’s of the same company. </li></ul><ul><li>Can link computers across town or span the world. </li></ul><ul><li>Common carriers are companies licensed by FCC to provide these services as leased lines. </li></ul><ul><li>Dedicated lines provides permanent connection between two or more locations </li></ul><ul><ul><li>Companies can build their own (microwave, fiber, etc.) </li></ul></ul><ul><ul><li>T1 and T3 high-capacity digital lines can be leased </li></ul></ul><ul><ul><li>Digital Subscriber Line (DSL) use telephone lines </li></ul></ul><ul><li>Connect with Router or Gateway </li></ul><ul><li>Will need a firewall to keep intruders out, which can be hardware and/or software (see after next slide). </li></ul>
  15. 15. GateWay Internet
  16. 16. <ul><li>Firewalls block unauthorized users from entering the network and unauthorized software from making outbound connections (spyware). </li></ul><ul><li>Windows includes personal Firewall protection. </li></ul><ul><li>Separate products can also be purchased. </li></ul>
  17. 17. <ul><li>All of this networking hardware requires software. </li></ul><ul><li>After connecting all of the hardware, software needs to be installed on the administrator’s computer. </li></ul><ul><li>Connect to the networking devices from the administrator’s computer and use the software to configure the hardware. </li></ul><ul><li>Then everything will work  . </li></ul>
  18. 18. <ul><li>Client computer requests services from server. </li></ul><ul><li>Server returns requested information / data. </li></ul><ul><li>Common uses include Web Server, Print Server, File Server, and Email Server. </li></ul>
  19. 19. <ul><li>Connect directly to another computer to create a LAN. </li></ul><ul><li>Need to activate Operating System features. </li></ul><ul><li>Server is not required. </li></ul><ul><li>All computers have equal status. </li></ul><ul><li>Users share each other’s files, printers, etc. </li></ul><ul><li>Common in small offices. </li></ul>
  20. 20. <ul><li>How is all of this communication possible? </li></ul><ul><li>Protocol - a set of rules for the exchange of data. </li></ul><ul><ul><li>Agreement on how data is to be sent and receipt acknowledged. </li></ul></ul><ul><ul><li>Needed to allow computers from different vendors to communicate. </li></ul></ul><ul><ul><li>Common protocols include Ethernet, Wi-Fi, TCP/IP </li></ul></ul><ul><ul><li>Transmission Control Protocol/Internet Protocol (TCP/IP) </li></ul></ul><ul><ul><ul><li>Permits any computer to communicate over the Internet. </li></ul></ul></ul><ul><ul><ul><li>Uses packet switching – original message is broken up; each piece has address of destination; each piece may take a different route; receiving computer puts all the pieces together. </li></ul></ul></ul>
  21. 21. <ul><li>Want to learn more… </li></ul><ul><ul><li>CIS190 Introduction to LAN </li></ul></ul><ul><ul><li>CNT140 Cisco Networking Basics </li></ul></ul><ul><ul><li>MST150 Microsoft Windows Professional </li></ul></ul><ul><li>HowStuffWorks-Firewalls </li></ul><ul><li>Review MCC’s Wireless Network: http://www.mc.maricopa.edu/its/net_services.html </li></ul>