basic concepts of computer network

2. Learning Outcomes
• Describe advantages of networking
• Describe the characteristic of two types of networks
• Describe the various classification of networks
• List the elements common to all client/server networks
• Describe the various computer network topologies
• Compare the characteristics of the different network
topologies
• State the organizations that set standards for
networking

3. What is Network?
• A combination of computer hardware, cabling,
network devices and computer software that
allows computers to communicate with each
other.
• The goal of any network is to allow computers
to communicate.
• Communication examples: web browser, AIM,
text messaging, email

4. Advantages of Comp. Network
• Data Exchange
• Hardware Resource Sharing
• Software Resource Sharing
• Data Security
• Increased Communication Capabilities
• Entertainment
• Backup - Avoid File Duplication and Corruption

5. Types of Networks
• Peer-to-Peer (P2P)
• Client Server

6. • Single computer / node CONNECTED to single
computer / node.
Peer to Peer
Network
Peer to Peer (P2P) Network

7. Peer to Peer (P2P) Network (cont…)
• P2P members usually perform similar tasks, sharing
of resources. Support 10 computers. Users of P2P is
located in the same geographical area
Advantages of a peer-to-peer network:
• Less initial expense - No need for a dedicated server.
• Setup - An operating system (such as Windows XP)
already in place may only need to be reconfigured for
peer-to-peer operations.

8. Peer to Peer (P2P) Network (cont…)
Disadvantages of a peer-to-peer network:
• Decentralized - No Centralized server.
• Security - Does not provide the security available on a
peer-to-peer network.

9. Client Server Network
• Multiple computer / device (CLIENTS) connected to a
SERVER to perform any network activities
File Server
Other
equipment

10. Client Server Network (cont…)
Advantages of a client/server network
• Centralized - Resources and data security are
controlled through the server.
• Security - More security then Peer-to-peer network.
• Flexibility - New technology can be easily integrated
into system.
• Interoperability - All components (client /server) work
together.
• Accessibility - Server can be accessed remotely and
across multiple platforms.

11. Client Server Network (cont…)
Disadvantages of a client/server network
• Expense - Requires initial investment in dedicated
server.
• Maintenance - Large networks will require a staff to
ensure efficient operation.
• Dependence - When server goes down, operations
will cease (stop) across the network.

12. RECAP!!
Can you explain differences
between Peer to Peer and
Client Server Network?

13. Category of Networks

14. Local Area Network (LAN)
• Simple connection within limited size of area
• Example: Single-building LAN or Multiple-building LAN

15. Metropolitan Area Network (MAN)
• Connection over the city
• Example: JB networks to Melaka networks

16. Wide Area Network (WAN)
• Large-size of area connection which connects all
over the world
• Example: Malaysia networks to Japan networks

17. RECAP!!
Can you explain your
understand on category of
networks?

18. • CLIENT
– Clients are the computers that can access the shared network resources
provided by a server
• SERVER
– Servers are the computers that provide the shared resources to network
users
• NIC (Network Interface Card)
– Device inside a computer that connects a computer to the network (network
adapter)
• NETWORK OPERATING SYSTEM (NOS)
– The software that runs on servers that enables the servers to manage data,
users, groups, security, applications, and other network functions.
Example: Windows Server 2008 R2, Mac OSX, UNIX, Linux
Elements of Client Server Networks

19. Elements of Client Server Networks (cont…)
• BACKBONE
– The devices that connect all of the clients and servers across the
network. Example Switches, routers, access points
• SEGMENT
– A segment is a specially-configured subset of a larger network. The
ways of increasing available bandwidth on the LAN
• TOPOLOGY
– A topology is a arrangement of a network, including its nodes and
connecting lines. Network geometry: 1) Physical topology 2) Logical
(or signal) topology.
• TRANSMISSION MEDIA
– The physical or nonphysical means through which data is
transmitted and received across the network. Example: Wire and
cables, radio waves

20. Network Topologies
Two categories of network topology
are:
• Physical – topology map recorded each host is
located, wiring is installed and the locations of the
networking devices that connect the hosts.
• Logical – host names, addresses, group
information and applications can be recorded on
the logical topology map. Describes the logical
pathway a signal follows as it passes among the
network nodes

21. Physical Network Topology

22. Logical Network Topology

23. Network Topologies
TOPOLOGY
BUS RING STAR HYBRID
TREE MESH

24. Bus Topology
• It is a multipoint topology.
• One long cable acts as a backbone to link all
the devices in the network.

25. Ring Topology
• Each device has a dedicated point-to-point line
configuration.
• Message will be passed to each device until it
reach the destination

26. Star Topology
 Each device has a dedicated point-to-point link only
to a central controller.
 It does not allow direct traffic between devices.

27. Mesh Topology
• A mesh topology provides redundant communication
paths between some or all devices .
Full Mesh
Partial Mesh

28. Tree Topology
 A tree topology integrates the star and bus
topologies in a hybrid approach to improve network
scalability.

29. Hybrid Topology
• The combination of two or more topologies.

30. Consideration to Choose Topology
• Money. A linear bus network may be the least
expensive way to install a network; you do not have
to purchase concentrators.
• Length of cable needed. The linear bus network uses
shorter lengths of cable.
• Future growth. With a star topology, expanding a
network is easily done by adding another
concentrator.
• Cable type. The most common cable is unshielded
twisted pair, which is most often used with star
topologies.
• Stability

31. Advantages & Disadvantages
TOPOLOGY ADVANTAGES DISADVANTAGES
Bus • Use of cable is economical.
• Media is inexpensive and
easy to work with.
• System is simple and
reliable.
• Bus is easy to extend.
• Network can slow down in heavy
traffic.
• Problems are difficult to isolate.
• Cable break can affect many users.
• Entire network shuts down if there
is a break in the main cable.
• Terminators are required at both
ends of the backbone cable.
Ring • System provides equal
access for all computers.
• Performance is even
despite many users.
• Failure of one computer can
impact the rest of the network.
• Problems are hard to isolate.
• Unmanageable in a large network
Star • Modifying system and
adding new computers is
easy.
• Centralized monitoring and
management are possible.
• Failure of one computer
does not affect the rest of
the network.
• If the centralized point fails, the
network fails.
• Costs are usually higher than with
bus or ring networks

32. Advantages & Disadvantages (cont…)
TOPOLOGY ADVANTAGES DISADVANTAGES
Mesh • System provides increased
redundancy and reliability
as well as ease of
troubleshooting.
• System is expensive to install
because it uses a lot of cabling.
Tree • Point-to-point wiring for
individual segments.
• Supported by several
hardware and software
venders.
• Overall length of each segment is
limited by the type of cabling
used.
• If the backbone line breaks, the
entire segment goes down.
• More difficult to configure and wire
than other topologies.

33. Type of Cable, Speed & Protocol
Topology Cable Speed Protocol
Bus, Star, Tree
Twisted Pair,
Coaxial, Fiber
10 Mbps Ethernet
Star
Twisted Pair,
Fiber
100 Mbps Fast Ethernet
Linear or Star Twisted Pair .23 Mbps LocalTalk
Star-Wired Ring Twisted Pair 4 Mbps - 16 Mbps Token Ring
Dual ring Fiber 100 Mbps FDDI
Bus, Star, Tree
Twisted Pair,
Fiber
155-2488 Mbps ATM

34. RECAP!!
What is differences between
all the various computer
network topologies??

35. Networking Standard Organization
• International Standard Organization (ISO)
• American National Standard Institute (ANSI)
• Institute of Electrical and Electronic Engineer (IEEE)
• Electronics Industries Association (EIA)
• International Telecommunication Union (ITU)
• Internet Architecture Board (IAB)
• Internet Engineering Task Force (IETF)
• Internet Society (ISOC)
• Internet Assigned Numbers Authority (IANA)

36. Source, Channel & Destination
• SOURCE - network or data resource (where the data
packets come from)
• CHANNEL - Transmission medium(in physics and
telecommunications, any material substance which
can propagate waves or energy) to ensure that the
data packets can be sent through the networks
• DESTINATION - network or data platform (where the
data packets is sent to)

37. Function of Hardware
• REPEATER - increasing the signals energy
• HUB / SWITCH
– Centralizing connection for all network devices (LAN only)
– Sending packets using MAC address
HUB
SWITCH
REPEATER

38. Function of Hardware (cont…)
• ROUTER - Forwarding packets in the network using MAC
and IP address (INTERNET)
ROUTER

39. • BRIDGE - Connecting two or
more different networks for
communication
Function of Hardware (cont…)
BRIDGE
GATEWAYS
• GATEWAYS - a device that acts
as a ‘MAIN PATH’ for all network
traffics.
• “Gate” to the Internet.

40. INDIVIDUALEXERCISE1
1. Describe the history and function of organizations the set
standards of networking?
2. Search and study all network topology , and from the
result draw your own network topology by using
physical network topology view.
• Individual Exercise. Submit on 29/06/2015
• Try to write and explain using your own words.
No Organization Description

41. I don’t stop when I’m tired.
I only stop when I’m done…