Overview: roadmap

1
Overview roadmap

• 1.1 What is computer network? the Internet?
• 1.2 Network edge
• end systems, access networks, links
• 1.3 Network core
• network structure, circuit switching, packet
  switching
• 1.4 Delay, loss and throughput in Internet
• 1.5 Protocol layers, service models
• 1.6 Networks under attack security

2
How is the Internet Organized

• A hierarchical structure.
• hosts combine to form a Local Area Network (LAN).
• LANs combine to form an Autonomous System (AS)
• Autonomous Systems combine to form the Internet.

Internetworked networks Internet !
3
Whats the Internet nuts and bolts view

• millions of connected computing devices hosts
  end systems
• running network apps

• communication links
• fiber, copper, radio, satellite
• transmission rate bandwidth

• routers forward packets (chunks of data)

4
Whats the Internet nuts and bolts view

• protocols control sending, receiving of messages
• e.g., TCP, IP, HTTP, Skype, Ethernet etc.
• Internet network of networks
• public Internet versus private intranet
• Internet standards
• RFC Request for comments

5
Whats the Internet an operational view

• a human protocol and a computer network protocol

human protocol
6
Whats the Internet an operational view

• human protocols
• specific msgs sent
• specific actions taken when msgs received, or
  other events

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

7
Whats a protocol?

• a human protocol and a computer network protocol

human protocol
Internet protocol example
8
Whats the Internet an operational view

• human protocols
• specific msgs sent
• specific actions taken when msgs received, or
  other events

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

9
Take home messages

• According to you, what are the three most
  important physical components of computer
  network?
• Name four Internet applications?
• What does a network protocol do?