Basic Concepts of Internet Technology

1
Basic Concepts of Internet Technology

• What is a computer network?
• Isolated computers vs. networked computers
• internetworking
• The Internet
• Whats a protocol?

2
What is a computer network?

• An interconnected collection of computers
• Examples of networks
• Telephone networks
• Satellite networks
• Mobile telephone networks
• Cable TV networks
• Intranets and extranets
• Internet
• Computer networks vs. other types networks
• (general, different types of data vs
  particular application)

3
Basic Concepts Isolated Machines
How to share data?
Independent Workstations (Local Processing)
4
Basic Concepts Networked Machines
5
Classifications of Computer Networks

• Based on size
• System/Storage area networks (SAN)
• within the same room
• connecting processors to storage servers.
• Local area networks (LAN)
• in a close proximity
• Metropolitan area networks (MAN)
• span a city
• Wide area networks (WAN)
• connecting computers situated anywhere
• Connects many networks together

6
internetwork

• A collection of networks

7
The Internet Topology
See http//www.cybergeography.org/atlas/topology.h
tml for more Internet topologies.
8
Whats the Internet a service view

• communication infrastructure enables distributed
  applications
• WWW, email, games, e-commerce, database.,
• cyberspace

9
Whats the Internet nuts and bolts view

• millions of connected computing devices hosts,
  end-systems
• pcs workstations, servers
• PDAs
• communication links
• fiber, copper, radio, satellite
• routers forward packets (chunks) of data across
  networks

10
Whats the Internet nuts and bolts view

• protocols control sending, receiving of msgs
• e.g., TCP, IP, HTTP, FTP
• Internet network of networks
• public Internet versus private intranet
• collection(s) of SAN, LAN, MAN, WAN

router
workstation
server
mobile
local ISP
regional ISP
company network
11
Whats a protocol?

• a human protocol and a computer network protocol

Hi
TCP connection req.
Hi
12
Whats a protocol?

• network protocols
• machines rather than humans
• all communication activity in Internet governed
  by network protocols

• human protocols
• whats the time?
• I have a question
• introductions
• specific messages sent
• specific actions taken when messages received,
  or other events

protocols define format, order of messages sent
and received among network entities, and actions
taken on message transmission, receipt