Computer Network

3. • Share resources from one computer to another.
• Create files and store them in one computer, access those
files from the other computer(s) connected over the network.
• Scalability increases the system performance by adding
more processors
• Security is the main characteristics of Computer network
where you can take necessary steps for protecting your data
from unauthorized access

6. Different Types of Networks
Local Area Network (LAN)
Metropolitan Area Network (MAN)
Wide Area Network (WAN)
Personal Area Network (PAN)

7. LAN
 It's a group of computers
which all belong to the same
organization.
 Data transfer speeds is up to
10 Mbps.
 A local area network can
reach as many as 100, or
even 1000, users.
LAN provides two different
operating modes
1. Peer-to-peer network
2. Client/server network

8. MAN
The metropolitan area network (MAN) is designed to
extend over an entire city.
It may be a single network such as cable television
network available in many cities.
A MAN uses distributed queue dual bus.
Range: Within 100 km (a city).
Bus A
Bus B
MAN

9. WAN

10. PAN
•A PAN is a network that is used for communicating
among computers and computer devices (including
telephones) in close proximity of around a few meters
within a room.
• It can be used for communicating between the
devices themselves, or for connecting to a larger
network such as the internet.
• PAN’s can be wired or wireless.

12. Network Topologies

13. Topology
•Topology refers to the layout of connected
devices on a network.
•The most common shapes are:
• Star
• Ring
• Bus
• Tree
• Hybrid

14. Star Topology
•A star topology is also called a hub topology, or a
centralized topology.
•A traditional approach to connecting devices where all
transmitted data passed through a central controller.
•This topology make routing very easy since the central
controller is connected to all other hosts, and knows the path
to all hosts.

15. Star Topology

16. Star Topology

17. Ring Topology
•A ring topology is one where all hosts are
connected together in a closed loop.

18. Ring Topology

19. Ring Topology
•Data is passed around in packets and typically is
passed in one direction around the loop.
•The packet knows its Source and Destination hosts.
•It will loop from the Source, around to the Destination
host, which makes a copy of the packet, and the original
packet continues the loop back to the Source.

20. Ring Topology

21. Bus Topology
•A bus topology is one where all the sites are
connected to a single communications line (or bus)
running the length of the network.

22. Bus Topology

23. Bus Topology
•Hosts can send data from one host to another via
the bus, the message will usually be sent in both
directions, and will keep travelling until they reach
the End-Point Controllers.
•So if I want to send from Host 1 to Host 3.

24. Bus Topology

25. Bus Topology
•Some bus topologies only allow the packets to
travel in one direction until the reach the end-point
controller, who can send it back in the opposite
direction if the destination hasn’t received the packet
yet.

26. Bus Topology

27. Tree Topology
•A tree topology is a combination of bus topologies.
The cables branch out, and there are no closed
loops.
•The tree begins at a Head End Controllers and
each branch terminates at an End Point Controller.

28. Tree
Topology

29. Tree Topology
•A packet from one node to another will be sent
down all branches, and will be absorbed by the End
Point Controllers of the branches that does not
contain the Destination host.
•Let’s do an example of going from Host 4 to Host
5.

30. Tree
Topology

31. Hybrid Topology
•A hybrid topology is one which combines any two
of the previous topologies.

32. Hybrid Topology

33. Hybrid Topology

34. Hybrid Topology
RING + BUS

35. Hybrid Topology

36. Hybrid Topology

37. Hybrid Topology
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38. Hybrid Topology
STAR + RING

39. Hybrid Topology

40. Hybrid Topology

41. Hybrid Topology
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42. Network Architecture

43. Client Server Model

44. Peer to Peer Connection