1. Review Session Chapter 5 Networking Chapter 6 System Development

2. Chapter 5 Data Communications and Internet Technology 5-layer network architecture The Internet and related concepts Enterprise Networks / Subnet Wireless Technologies

3. 5-layer architecture Read: page 119 ~ 121 for details. Figure 5-4 (page 119)

4. Applicati on Layer Transport Layer Internet Layer Data Link Layer Physical Layer Computer A Internet Layer Data Link Layer Physical Layer Computer B Router A Internet Layer Data Link Layer Physical Layer Router N Applicati on Layer Transport Layer Internet Layer Data Link Layer Physical Layer Point-to- point End-to-end Layer 1: physical connectivity. Road and buses Layer 2: how to communicate with your neighbors (control traffic and reduce error of physical layer) truck-driver: deliver the package to the next station. Layer 3: an overall connectivity map + routing algorithm. Allow connectivity of one network to another. Logistic manager (knows how to connect all the transit stations, and inform the truck driver where to send the mail to the next transit station) Layer 4: establish end-to-end connectivity between any two computers (may not be in the same network, connected by the 3 rd layer) clerk (receive your mail, and notify you whether the mail can be sent through) Layer 5: allow software (application programs) to talk to each other once layer 4 connection is established. Correspondents Layer 1: physical connectivity. Road and buses Layer 2: how to communicate with your neighbors (control traffic and reduce error of physical layer) truck-driver: deliver the package to the next station. Layer 3: an overall connectivity map + routing algorithm. Allow connectivity of one network to another. Logistic manager (knows how to connect all the transit stations, and inform the truck driver where to send the mail to the next transit station) Layer 4: establish end-to-end connectivity between any two computers (may not be in the same network, connected by the 3 rd layer) clerk (receive your mail, and notify you whether the mail can be sent through) Layer 5: allow software (application programs) to talk to each other once layer 4 connection is established. Correspondents Understand how the 5 layers work together

5. Understand how data is converted to electric signals Break into pieces, add header data control of each layer.

6. Checklist Basic concepts: –Computer network –LAN/WAN/internet  Internet –VPN, Tunneling, Intranet/Extranet Technical terms: e.g. UTP, Twisted Pair Lines, Ethernet, TCP, UDP, etc. Domain Names: describe the type of website based on the domain name. IEEE 802 and the protocols How to use DOS command the check your IP address? IPv4: 32 bits. Identify a valid IP address.Identify a valid IP address. Internet  future of the Internet. (slides 42) Institutions / Organizations –Department of Defense / NSF / ICANN / ISO / IETF / IEEE

7. Exercise Which of the following can be an IP address? (explain why) –144.37.2.3 –144.144.144 –144.2.3.30.40 –144.37.2.267

8. Types of Networks LAN: (IEEE 802) –wired: three basic topologies (pros and cons, slides 21) –wireless: WiFi ~ IEEE802.11 (advantage of wireless) WAN – connecting to remote locations –leased lines / use the publicly available networks (e.g. telephone network, Internet), pros and cons (page 126, figure 5-12, WAN part)

9. IEEE StandardA.K.ARangeSpeed WPANIEEE802.15 Bluetooth ~30 feet1Mbps WLAN IEEE 802.11 Wi-Fi ~ 300 ft 11~54Mbps ~802.11b 11Mbps (slower) ~802.11g 54Mbps (interference) WMANIEEE 802.16Wi-Max~ 30 miles75Mbps WWANIEEE802.20N/A Wireless Computer Networks (radio wave)

10. Computation Problems Speed computation Time = Total Data Volume / Effective speed (conversion: 1B=8 bits, 1KB = 8*1024 bits, etc.) Subnet mask: –How many computers in the subnet? 2 n –Given the number of computer, figure out n, convert to subnet mask.

11. Chapter 6 Systems Development The concept of Systems Development –Range of systems development, complexity compared to program development Risks and challenges associated with systems development System Development Methods –SDLC –RAD –OOD –XP Full name of the four methods. Characteristics of those methods (particularly the first two).

12. SDLC The most formal way to set up a large Information System Widely adopted methods by large organizations 5 formal phases: –System Definition –Requirement Analysis  the most important phase –Component Design –Implementation –System Maintenance Describe the main activities in each phases  What are the inputs for each phase? What are the outputs?