1. Chapter 3 The Basics of Networking
Fluency
Chapter 3
The Basics of Networking

2. What is the Internet? What’s your address?
The totality of all wires, fibers, switches, routers, satellite links, and other hardware for transporting information between addressed computers.
What’s your address?

3. How have computers changed our lives?
For the better?
For the worse?
What effect has it had on the influence of the English language?

4. Communication Categories
Synchronous
Asynchronous
Broadcast
Multicast
Point-to-point
So what category
does the Internet fit into?
Synchronous – both sender and receiver are active at the same time – e.g. telephone
Asynchronous – sending and receiving occur at different times – e.g. letter
Broadcast – single sender & many receivers – e.g. television & radio
Multicast – many receivers but specialized – e.g. car racing magazine
Point-to-point: opposite of broadcast & multicast

5. Computer addresses
Each computer connected to the Internet is given a unique IP (Internet Protocol) address
IP address – currently series of 4 numbers separated by dots: e.g
Each # can be in range of 0-255
Internet protocol moving to Version 6 (IPv6) with a 16-byte address system.

6. Domain Names Domain – related group of networked computers
A more human-friendly way of addressing computers based on a hierarchy of domains.
Domain – related group of networked computers
markel.faculty.msmc.edu
Domain Name System (DNS) translates the domain name into its 4-number IP address
DNS server – a computer that keeps a list of the symbolic names and the corresponding IP addresses

7. Top Level Domains .com .org .mil .net .gov .edu
In addition there’s a 2-letter country code: .uk, .au, .fr etc. that identifies countries
There is a US code - .us

8. TCP/IP Transmission Control Protocol/Internet Protocol
TCP – breaks a transmission up into small fixed-size packets
Each packet contains the following:
Data being sent
Destination IP address
Sequence #
IP - re-orders the packets at the destination to assemble the information
Vincent Cerf, one of the IP pioneers, used a postcard analogy to describe the TCP/IP process

9. Characteristics of TCP/IP
Packets are independent
Packets are transmitted over the Internet using whatever route is available
Transmissions often rely on multiple technologies to move the packets through the Internet:
Telephone lines
Fiber optics
Dedicated lines

10. Networks
WAN – wide-area networks: networks designed to send information between two locations not directly connected.
Packets take several “hops” before delivery
LAN – local-area network. Computers are directly cabled or “channeled” together. Most LANs use Ethernet technology.

11. Connecting to the Internet
ISP – Internet Service Provider
Examples?
Connection method:
Modem
DSL (digital subscriber line)
Network connections
LANs connect to the Internet via a gateway. Information from a remote Web computer is sent across the Internet, through the gateway to the organization’s intranet, and across the LAN to the user’s computer.

12. The World Wide Web
Web servers – computers programmed to send files to browsers running on other computers connected to the Internet.
Subset of the Internet
Each web page has a unique address called a Universal Resource Locator or URL
Built on a client-server relationship
When you request a page, your browser is a client of the web server.

13. The URL The URL consists of three parts:
Protocol: - stands for Hypertext Transfer Ptococol
Server computer’s name
Pathname of the particular page

14. Structure of emails and URLs
The receiver can have dots, dashes, and underscores.
URL:
The domain address has one or more dots, no slashes.
Spaces are not allowed in or URLs.

15. Describing a Web Page
Web pages stored as a description of how they should appear
Description file is called the source file
Written in HTML (hypertext markup language)
Markup languages describe document layout
Hypertext – breaks linear sequence of text through links: non-linear and dynamic
HTML was invented by Tim Berners-Lee in 1990 when he was working for CERN, the European Laboratory for Particle Physics.

16. Directory Organization
root page
folder
folder

17. path

18. Th . . .th that’s all, folks!