Computer Communication Networks Class 1

Study Notes

Introduction to Computer Networks

A computer network comprises end-systems or hosts connected through communication links and packet switches.
End-systems generate or receive data in packets, collections of bits.
The sequence of packet switches and communication links is termed as a route or path.
Administration of a computer network is usually handled by a single entity.

Internet Overview

The Internet is a vast network interconnecting billions of computing devices worldwide.
It provides services for distributed applications, which run across different hosts.
Key historical developments include DARPA, ARPANET, packet switching, TCP/IP, and DNS.

Notable Inventions and Inventors

World Wide Web: Tim Berners-Lee, MIT, 1989-90.
Email: Ray Tomlinson, BBN, 1972.
DNS: Paul Mockapetris, USC, 1982.
RFC: Stephen Crocker, UCLA, 1969.
Packet Switching: Leonard Kleinrock, UCLA, 1961.
TCP/IP: Bob Kahn and Vincent Cerf, DARPA/SRI, 1972-73.
Ethernet: Bob Metcalfe, Xerox PARC, 1973.

Internet Ownership and Control

Internet access is provided by Internet Service Providers (ISPs), which charge subscription fees.
End-systems connect to ISPs at points-of-presence (PoPs), with thousands of PoPs indicating ISP reach.
PoPs include routers, link layer switches, and communication links.

ISP Hierarchy and Revenue Generation

End users pay access ISPs, which then pay regional ISPs, leading to Tier 1 ISPs.
Tier 1 ISPs can have bilateral agreements to share bandwidth and resources.
Peering or multi-homing ISPs may share revenue based on resource utilization.

Distributed Applications and Services

Applications operate independently on hosts, exchanging messages via internet socket interfaces.
Protocols determine message format and exchange order and govern actions taken during transmission or reception.
Services like reliability and guaranteed rates are provided by hardware or software tied to devices.

Network Edge

The network edge encompasses computer networks that connect to the internet, categorized as access networks.
End-systems can be classified into clients and servers.
Gateways are routers connecting access networks to ISPs.
Access networks can be classified based on size (local area, home, wide area), topology (tree, star, ring, bus, point-to-point), and physical media (wired or wireless).

Description

This quiz covers the fundamentals of Internet architecture and its applications, specifically focusing on terminology and introduction to the Internet. It references the textbook section on pages 32-39, providing a solid foundation for understanding computer communication networks.