What is network?

Types of network

◦ LAN – Local Area - Ethernet◦ WAN – Wide Area - Internet◦ MAN – Metro. Area - LAN<=50km◦ Wireless - WiFi◦ PAN – Personal Area – Bluetooth◦ Mobile Networks - CDMA/GSM/3G/4G etc◦ WSN - Sensor Networks◦ RFID (Radio Frequency Identification)

Image Source: http://oscar.iitb.ac.in/images/weeklyimages/Networking/Bluetooth.jpg

Overview A typical Network

Repeater◦ Signal boost◦ Example: Hub

Bridge◦ Connections same types of

networks◦ Example: Switch

Routers◦ Connects different types of

networks Gateway

Connects different types of protocols

Picture Source: http://img.zdnet.com/techDirectory/WIFIBRDG.GIF

Explanation Example

Server Port Numbers 80 – HTTP 20/21 – FTP 25 – SMTP 53 – DNS Client Port Numbers 1025 - 65535

Image Source: http://www.isaserver.org/img/upl/2004rp21109170267623.gif

Type of Cables for LAN RJ 45 Cable

RJ = Registered Jack RJ 11 – Telephone RJ 45 – Ethernet

◦ Straight Through◦ Crossover◦ Rollover

Picture Source: http://en.wikipedia.org/wiki/Ethernet

http://www.bizwaremagic.com/quick_internet_history.htm

http://www.walthowe.com/navnet/history.html

CyberAtlas.com

History ARPANET (Advanced Research Projects Agency Network) was the first packet switching network

created by United States Department of Defense during cold war.

Internet was first brought online in 1969 connecting 4 computers between UCLA, Stanford Research Institute, UCSB, and the University of Utah

Tim Berners-Lee joined with others, proposed a new protocol in 1989 for information distribution which is now known as World Wide Web.

It took 38 years for radio to reach 50 million users, 13 years for TV, and only 5 years for the Internet.

http://www.internetworldstats.com/stats.htm

Image Source: http://www.teach-ict.com/technology_explained/packet_switching/packet.switching.gif

http://visualroute.visualware.com/

cmd – tracert www.websitename.com

Link What is inside the net?

http://video.google.ca/videoplay?docid=4523214973725842000&ei=JTW6Su_3PI-MqAKnouzyAQ&q=warriors+on+the+net&hl=en#

http://www.youtube.com/watch?v=Ve7_4ot-Dzs

Picture Source: http://www.portices.fr/formation/Res/Internet/Res/InternetMonde.gif

Overview Complications

Image Source: http://filipspagnoli.files.wordpress.com/2009/02/china-censorship-of-the-internet-cartoon.gif

http://sohomediatech.com/images/SOHO-MediaTech-wired-network.jpg

http://www.securitystats.com/

At its peak infection rate, about 1 in 12 emails on the Internet were MyDoom Viruses 

It is estimated that PC Viruses cost businesses approximately $55 Billion in damages in 2003.

FTC received 161,000 identity theft complaints last year, the FBI estimates the actual number of victims is probably closer to 500,000

Virus – Inside the machine Worm – Machine to machine Spyware – Collect information from the computer Adware – Ads popup Trojan – Type of malware control by a hacker Phishing – fool the recipient by asking personal

information Network intrusions Many more

Biometric

Firewall

Cryptography

Anti-Spyware

Antivirus

IDS

Mgmt rules

Security