Computer Literacy:

Introduction to Computer Networks

Reading: Chapter 15 of Kershner - can skip FAX technology (pp. 401-402)

Network: a collection of autonomous computers that can

communicate with one another

hosts, nodes, communication channels

NETWORK HARDWARE

Communication channels

twisted-pair copper cables

coaxial copper cables

fiber optic cables

microwave channels

Bandwidth: amount of data that can be transmitted in a given time

bps, cps, baud

narrowband, voice band, broadband

Digital v. analog signals

why modems are needed

Categories of networks

LANs e.g., Novell networks

WANs e.g., ARPANET, BITNET, NSFNET

Internetworks e.g., "the Internet"

Network topologies

LANs: ring, bus

generally: star, ring, fully connected, many others

Wireless networks

NETWORKS AT SMITH: see slides!
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-- Special network nodes: file servers, routers --

NETWORK SOFTWARE

Some functions of network software

data format

error-checking

protocols for sharing channels

routing: choosing a route, dealing with congestion

common address format

Network protocols

ex.: TCP/IP

TCP/IP is the Internet's protocol

Packet switching

IP: packet formatting

TCP: Sequencing, flow control

Domain names, Domain Name Servers

NETWORK APPLICATIONS

Client-server model

E-mail, FTP, TELNET, Gopher, NetNews, WWW