Review Session

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
Understand how the 5 layers work together
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 3rd 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
Computer B
Computer A
End-to-end
Point-to-point
Point-to-point
Router N
Router A
5
Understand how data is converted to electric
signalsBreak 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.
• 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
Wireless Computer Networks (radio wave)
10
Computation Problems

• Speed computation
• Time Total Data Volume / Effective speed
• (conversion 1B8 bits, 1KB 81024 bits, etc.)
• Subnet mask
• How many computers in the subnet? 2n
• 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?