1. COMPUTER NETWORKS and INTERNETS
Chapter 1
Introduction and overview

2. Introductions
Name
Experience
Major

3. review Base 10 (Decimal) Base 2 (Binary) Network Devices Switch Hub
Router

4. Growth of computer networking
In the late 1960’s the first workable prototype of the Internet was ARPANET (Advanced Research projects Agency Network)
Funded by the U.S. Department of Defense
UCLA, Stanford, University of California-Santa Barbara, and University of Utah installed first nodes
First message was “LO” meaning to Login
1973 Global networking (Internet) is born when University College of London (England) and Royal Radar Establishment (Norway) connect to ARPANET.
Public population goes World Wide Web
1990 – HyperText Markup Language (HTML) is developed. This is used today.
1991 – World Wide Web (WWW) is introduced to the public
1994 – Netscape (Internet Browser) and Yahoo is created.

5. Growth of computer networking

6. The five key aspects of networking
1. Network Applications and Network Programing
Span a wide range that includes
File upload or download
Web browsing
Telephone calls
Distributed database access
Video conferencing
2. Data Communications
Data communication refers to the study of low-level mechanisms and technologies used to send information across a physical communication medium.
Copper wire, light beam, radio wave

7. The five key aspects of networking
3. Packet Switching and Networking Technologies
Early communication networks evolved from a physical wire connecting two parties to complete a circuit.
Similar to telephone switch board
Packet switching changed networking in a fundamental way
Instead of a dedicated circuit, multiple senders transmit data over a shared network
Packet switching divides data into small blocks called packets.
Devices (routers, switches, etc.) are throughout the network that contains information on how o reach end device.

8. The five key aspects of networking
4. Internetworking with TCP/IP
What does a protocol mean
Transmission Control Protocol/Internet Protocol (TCP/IP)
Internetworking is a concept that allows computers (end devices) to communicate together.

9. The five key aspects of networking
5. Additional Networking Concepts and Technologies
Assessing network performance
Allowing multimedia and IP telephony
Home automation

10. Public and private parts of the internet
Public network is available to subscribers.
Pay for subscription (and register for the address). Knows as a service provider.
Internet Service Provider (ISP)
Routed on Internet
Private network is controlled by one particular group
Consumer
Least expensive owned by an individual. Probably a wireless router in home.
Small Office/Home Office (SOHO)
Connects two or more (typically less than 10) computers together for the Internet. Most are battery backup to minimize interruptions.
Small-to-medium business (SMB)
Many computers in multiple offices. Typically uses several routers
Large enterprise
A lot of IT infrastructure. Several geographical sites.

11. Networks, interoperability, and standards
Communications always involves at least two entities
Communications involves many details
All agree on the voltage
Exact way electrical signals are used to represent data
Initiate and conduct communication
Format of the message

12. Protocol suites and layering models
A set of protocols must be constructed carefully to ensure that the resulting communications system is both complete and efficient
Protocols are designed in complete cooperative sets called suites or families
Each protocol in a suite handles one aspect of communication. Together all protocols in the suite handle all aspects of communication.
Hardware failure and other exceptional conditions
A layer model describes how all aspects of communication work together.
The visual appearance of figures used to illustrate layering is called stack

13. Protocol suites and layering models (cont.)

14. How data passes through the layers

15. Headers and layers Encapsulation / Deencapsulation
Protocol Data Units (PDU)
Segments = Transport
Packets = Internet,
Frames = Network Access (Interface) or MAC
Bits = Physical