1.88k likes | 4.24k Views
Basic Concepts of Internet Technology. What is a computer network? Isolated computers vs. networked computers inter networking The Internet What’s a protocol?. What is a computer network?. An interconnected collection of computers Examples of networks: Telephone networks
E N D
Basic Concepts of Internet Technology • What is a computer network? • Isolated computers vs. networked computers • internetworking • The Internet • What’s a protocol?
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)
Basic Concepts: Isolated Machines How to share data? Independent Workstations (Local Processing)
Client-Server Model File Servers Workstations (Local Processing) Computer Network Application Servers Basic Concepts: Networked Machines
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
internetwork • A collection of networks
The Internet Topology See http://www.cybergeography.org/atlas/topology.html for more Internet topologies.
communication infrastructure: enables distributed applications: WWW, email, games, e-commerce, database., cyberspace What’s the Internet: a service view
millions of connected computing devices: hosts, end-systems pc’s workstations, servers PDA’s communication links fiber, copper, radio, satellite routers: forward packets (chunks) of data across networks router workstation server mobile local ISP regional ISP company network What’s 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 What’s the Internet: “nuts and bolts” view router workstation server mobile local ISP regional ISP company network
a human protocol and a computer network protocol: TCP connection reply. Get http://gaia.cs.umass.edu/index.htm Got the time? 2:00 <file> time What’s a protocol? Hi TCP connection req. Hi
human protocols: “what’s the time?” “I have a question” introductions … specific messages sent … specific actions taken when messages received, or other events network protocols: machines rather than humans all communication activity in Internet governed by network protocols What’s a protocol? protocols define format, order of messages sent and received among network entities, and actions taken on message transmission, receipt