Transcript Chapter 7 Networks and the Internet

Chapter 7
Networks and the Internet
Networks
Sharing resources among
multiple computers
(workstations)
Local Area Networks
Wide Area Networks
Servers run the
network and share
resources
Workstations are
computers connected to
the network
Hubs are connection
points between
workstations and
servers
Network Connectivity,
Communications and Security
Protocols
Workstations on network must
all speak same language
Bandwidth
Capacity of transmission media
Passwords
Assign access rights for each
user to increase security
Firewalls
Prevent unauthorized access
Sharing and Communicating via
the Network
Resource Sharing
Programs installed on server,
shared by workstations
Site licenses
Economical and efficient for
upgrades
Backup Strategies
Redundant systems, backup
disks, local copies
Shared Resources
Data
Access files from anywhere
Administrative Tools (Groupware)
Calendars, address books,
reservations lists
Academic Tools
Monitor student activity
Hardware
Share printers on network
Communication via Email
Key communication tool in
networked environment
Teachers can communicate with
colleagues, students, and
parents
Students can become “ebuddies” and “e-mentors”
Scheduling not an issue
Expand Connectivity through
Telecommunication
Telephone Lines
DSL
Cable Modems
Satellite
Modems
“Translating devices”
MOdulate and DEModulate
digital signals across analog
phone lines
Expand network beyond LAN
Allow users to access network
remotely
Digital Subscriber Lines (DSL)
High-speed digital phone line
Up to 30x faster than analog
Voice and Data transmissions
Eliminates need for 2 phone lines
Cable Modems
Use existing cable TV lines
Generally faster than DSL
Not available everywhere
Satellite Connections
Connect using TV satellites
High-speed connection
Require subscription to service
Greater availability for remote
locations
The Internet
Connects millions of networks
across the globe
Diverse computers access data
similarly using TCP/IP
Internet Service Providers (ISP’s)
provide access
Internet Communications
Synchronous Communication
Internet Relay Chat, Video
Conferencing
Asynchronous Communication
Email, bulletin boards, forums,
newsgroups, web pages,
mailing lists
File Transfer Protocol