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!
Image 1
Image 2
Image 3
Image 4
-- 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