Introduction to Internet

Motivation

• Sharing of resources.
• Robust communication infrastructure.

Timeline

• 1961 - Invention of packet switching
• 1964 - ARPAnet comes into existence
• Early 70's - TCP/IP designed
• 1.1.1983 - Transition to TCP/IP
• 1986 - NSFNET backbone created
• 1995 - Full transition to commercial Internet

POTS (Pain Old Telephone System)

• One service model - voice.
• Constant bit rate.
• Traffic engineering using voice call models.
• Flow control and error recovery is manual.
• Congestion control via busy signal.
• Operates on "Maximum Effort" methodology.

Internet properties

• Multitude of applications.
• Bursty traffic.
• No universal traffic engineering mode.
• Protocols provide flow, error and congestion controls.
• Operates on "Best Effort" methodology.