1. TexPREP Summer Camp Computer Science
Network concepts
TexPREP Summer Camp
Computer Science

2. Network Is a collection of computers and devices linked together.
Advantages:
We can share resources (files, printers, programs, information, etc.).
We can access things that are far away.
Facilitate communications.
Disadvantages:
More strict security measures are required to prevent users from affecting each other.
Are vulnerable to hackers and viruses.
If the server fails all users are affected.

3. Communications componentsSD CD RD CC
In order to establish a communication between devices we need:
Sending device (SD): sends the information to the other device. It is typically a computer.
Receiving device (RD): receives the information. It is a computer or another device (for example, a printer).

4. Communications components
Communication devices (CD): one at each end, they convert the information into signals that can be transmitted through the communications channel.
Some examples are:
DSL modems
Cable modems
Network cards
Wireless access points
Routers
motorola.com
tradenote.net

5. Communications components
Communications channel (CC): Is the transmission media used to transmit the information.
Bandwidth is amount of data that can travel over a communications channel. It is usually expressed in bits/sec, bytes/sec (digital devices) or Hz (analog devices).
Types of transmission media:
Twisted-pair
Coaxial cable
Fiber optic
Radio frequency
Cellular radio
Microwave
Satellite

6. Communications components
Examples of communication channels: twisted pair wire optical fiber coaxial cable electromagnetic wave
communication.howstuffworks.com
chinadropwire.com
scienceprog.com
computercablestore.com

7. Classification of Networks
Networks may be classified in various ways. LAN (room or building) Geographical MAN (city or small region) area covered WAN (country, continent, world) Client/Server Architecture Peer to Peer (P2P) Internet P2P

8. Classification of Networks
astro.co.uk

9. Classification of Networks
Client/Server
ipt2009.wikidot.com

10. Classification of Networks
Transmission WIRED media type WIRELESS
WIRED

11. Classification of Networks
WIRELESS
microsoft.com

12. Network Protocols
A network protocol is a formal set of rules and conventions that govern how network devices (computers and other peripherals) must interact. Three of the most popular ones are: TCP/IP (Transmission Control Protocol/Internet Protocol) ETHERNET: used in wired LANs. IEEE (Wi-Fi): used in wireless LANs. It is compatible with ETHERNET.