What is the Internet?

Question 1

Internet

Answer 1

collection of thousands of individual networks and organizations, each of which is run and paid for on its own

runs on client/server model of information delivery

Question 2

5 groups that guide the Internet’s growth

Answer 2

• Internet Society
• InterNIC
• Internet Architecture Board (IAB)
• Internet Engineering Task Force (IETF)
• World Wide Web Consortium (W3C)

Question 3

Internet Society

Answer 3

* Internet Society- non-profit, supports Internet Architecture Board (IAB)

Question 4

InterNIC

Answer 4

* InterNIC- and other registrars are responsible for maintaining the domains registered through registries; tracks the connections between Internet addresses

Question 5

Internet Architecture Board (IAB)

Answer 5

* Internet Architecture Board (IAB)- handles Internet’s behind the scenes and architectural issues

Question 6

Internet Engineering Task Force (IETF)

Answer 6

* Internet Engineering Task Force (IETF)- responsible for overseeing how the Internet’s TCP/IP protocols evolve

Question 7

World Wide Web Consortium (W3C)

Answer 7

* World Wide Web Consortium (W3C)- develops standards for the evolution of the WWW; industry consortium run by MIT

Question 8

Registrars

Answer 8

Private companies that oversee registration of Internet domains

Question 9

Individual local networks

Answer 9

can be found in private companies, universities, government agencies, online services

Question 10

ISPs

Answer 10

Internet service providers (ISPs) have networks, sell people monthly connections to the Internet. They run their own segments of the Internet and might supply long-distance connections called backbones.

Question 11

Regional networks

Answer 11

Local networks join in consortiums known as regional networks- regional networks provide and maintain Internet access within a geographic area. Can consist of smaller networks and organizations within the area that have banded together to provide better service

Question 12

Backbones

Answer 12

* Private companies who make money by selling access to their lines build backbones which are high-capacity lines that carry enormous amounts of Internet traffic

* NASA and the NSF also pay for some backbones

Question 13

client

Answer 13

typically local personal computer or software that runs on it

Question 14

server

Answer 14

(also known as host)- more powerful computer that houses the data/server software

Question 15

HTTP

Answer 15

hypertext transfer protocol, the protocol used by the World Wide Web

Question 16

DNS

Answer 16

Domain Name System, the way in which computers contact each other

When someone on Internet wants to visit website, types in address via URL. DNS translates the address into an IP address, which marks the locatin of a computer on the Internet similar to an address

Question 17

Major domain

Answer 17

letters at the end of the address: .com, .edu. gov

Question 18

name servers

Answer 18

computers responsible for keeping track of changes in IP addresses and translating them between IP addresses and domain addresses.

name servers contain tables that match alphanumeric Internet addresses to numeric IP addresses

Question 19

Standard vs. dynamic IP address

Answer 19

IP= internet protocol

many ISPs use dynamic IP addresses because of limited number of IP addresses

Question 20

URL

Answer 20

Uniform Resource Locator

Question 21

DHCPDISCOVER & DHCPOFFER

Answer 21

To obtain dynamic IP address, computer sends a broadcast message called DHCPDISCOVER packet to network or ISP

Received by DHCP server, which checks list of available IP addresses

DHCP server broadcasts response called DHCPOFFER packet

Question 22

NAT

Answer 22

Network Address Translation

used to resolve problem of not enough IP addresses and protects PCs inside a network.

each router has its own IP address, assigned by ISP. This is visible on Internet.

Each PC on home network gets an internal IP adress from the router and is used only for communications within the network itself, and is not visible to the outside world

When the PC browses the Internet, it appears to have the routers IP