1. Computer networks
Internet, Intranet, Extranet, Lan, Wan, characteristics and differences.

2. Table of Content Generally about Computer Network
Network Classification
Types of Networks
Network Hardware Componenets
Local Area Network (LAN)
Ethernet
Star Topology
Mesh networking
Wireless Network: Wi-Fi
Wide area network

3. Table of Content Internet TCP Protocol Packet/Switching
Client/Server Networking
Internet Functions
Intranet
Extranet
LAN & WAN comparison
Intranet & Extranet comparison

4. Generally about Computer Network…
group of interconnected computers
allows computers to communicate
share resources and information

5. Network Classification

6. Types of Networks

7. Network Hardware Componenets

8. Local Area Network (LAN)
small geographic area (e.g. room, office)
contrast to wide-area networks (WANs)
controlled by one administrative authority
usually high speed
always shared

9. Ethernet developed by Xerox in 1973–1975 standardized as IEEE 802.3
has replaced token ring, FDDI and ARCNET
usually uses twisted pair cable ( RJ-45)

10. Star Topology one of the most common
hub accepts data from a sender and delivers it to the receiver
reduces the chance of failure by connecting to a central node
good performance - passing the Data through unnecessary nodes is prevented

11. Mesh networking
continuous connections around blocked paths by “hopping” from node to node until the destination is reached.
can still operate even when a node breaks down
Wi-Fi mesh is typical

12. Wireless Network: Wi-Fi
cheap networking solution
radio waves instead of cables
three standards :
802.11a, b and g
2 modes – Infrastructure, and Ad-hoc
Hotspots – easy internet access

13. Wide Area Network (WAN)
computer network that covers a broad area
crosses metropolitan, regional, or national boundaries
uses routers and public communications links
Example: Internet

14. Wide Area Network (WAN)
used to connect LANs and other types of networks together
Option for WAN connectivity
Leased Line
Circuit switching
Packet switching
Cell relay
Speed from 1200 bits/s to 6 Mbit/s

15. Wide Area Network (WAN)
Turning into VPN to interconnect their networks, in that way

16. Internet
Vision Appeared first in a 1946 comic science-fiction story “A Logic Named Joe”
SAGE program connecting, radar systems
On August 6, 1991, CERN, straddled the border between France and Switzerland
During the 1990s, it was estimated grew by 100% per year, with boom in 1996 and 1997

17. Internet global system of interconnected computer networks
consists of millions of private and public networks

18. TCP Protocol TCP= Transmission Control Protocol
Developed by US Department of Defense in 70s
Set of network rules
4 layers structure

19. IP protocol provides addressing for computers
IP Version 4 is the initial version
~4.3 billion (109) Internet hosts
IP v6 provides vastly larger addressing capabilities
IPv6 will be not compatible with IPv4

20. Packet/Switching Slicing digital message into packets (parcels)
Size of a packet = 128 bytes (X.25)
Security of the data

21. Client/Server Networking
Model of networking
Balanced architecture
one or more Server Computers
Example: Internet

22. Internet Functions E-mail File-sharing Instant messaging Internet fax
World Wide Web
Voice over IP
Mobile VoIP

23. Intranet Private computer network
secure sharing organization's information or operational systems with its employees.
The same architecture as in Internet
private version of the Internet

24. Intranet
possible access to the Internet, then geteway with firewall is applied
Intranet delivers
tools and applications,
collaboration (to facilitate working in groups and teleconferencing)
sophisticated corporate directories
sales and Customer relationship management tools
project management etc
In large intranets, traffic is often similar to public website traffic

25. Extranet Uses Internet protocols, network connectivity
Share informations as intranet
The number of clients is extended to people outside the company
interconnections are over a shared network rather than through dedicated physical lines as in intranet

26. LAN & WAN comparison LAN WAN Small area covered
Use public communication links
Usually low speed
Uses Wi-Fi, Ethernet cables
Large area area covered
Use public communication links
Usually fast speed
Uses optic wires, microwaves, satellites

27. Intranet and Extranet comparison
connects users in company
shared network
single company's administrator
Don’t need so much security
connects user inside and outside company
Dedicated physical lines
multiple company's administrator
Requires more securtity

28. The End