NETWORK???

                    ASSALAMUALAIKUM and HELLO everyone.....This is my second semester in College Matriculation Pahang.This is my third post and its about the network.The topic of network is first topic that I learn in my second semester.I'm so excited nowww...

                 

       What the means by network ?

• Network is the collection of the computer and devices that connect together via communication                devices and transmission media.        

      Basic concept of network.

      Type of communication device :

1.  Router

• A communication device that connect multiple computers or other routers together and transmit data to its correct destination on a network.

2.   Dial-up modem

•  A communication device that can convert digital signals to analog signal and analog signals to digital       signals.

3.  Network card

• A communication devices that enable a computer or device that does not have built-in networking capability to access a network.

4.  Switch

• A connection device similar to hub but more sophisticated including functionality that allows it to control and manage data transmission.

5.  Hub

• A connection device that allows multiple connection to the network.

6.  Wireless access point (WAP) 

• A central communication device that allows computers and devices to transfer data wirelessly among themselves or to transfer data wirelessly to a wire network using wireless technologies such as Wi-Fi.

           Two type of transmission media

1.  Guided Media (wired)

• Shielded Twisted Pair
• Untwisted Pair (UTP) 
• Coaxial Cable
• Fiber Optic

2.  Unguided Media (wireless)

• Cellular Radio
• Infrared
• Microwave
• Satellite

        What is network architecture?

• The configuration of design computers, devices and media on network.

       Client/Server Network;

   
http://www.ianswer4u.com/2011/05/client-server-architectures.html#axzz4Vn66VmHM

• On a client/server network,one or more computers act asa server, and the other computer on the network request services from the server.

       Peer-to-Peer network;

http://ejj3611.blogspot.my/2009/06/6-difference-between-client-server.html

• Each computer, called a peer has equal responsibilities and capabilities, sharing hardware (such as printer) , data, or information with other computers on the peer-to -peer network.

      What is network topology?

• A network topology refers to the layout of the computers and devices in a communications network.

              Bus Network Topology;

• A  bus network consists of a single central cable (backbone), to which all computers and other devices connect.

                 

http://www.bbc.co.uk/schools/gcsebitesize/ict/datacomm/2networksrev4.shtml

         Advantages:

1. Inexpensive and easy to install.
2. Failure of one node usually does not affect the rest of the bus network.

         Disadvantages:

1. The break in the main cable (backbone) will prevent all systems from accessing the network.
2. It is difficult to identify the problem if the entire network shut down.

        Star Network Topology: 

https://www.kullabs.com/classes/subjects/units/lessons/notes/note-detail/1118

• All the computers and other nodes on the network connect to a central devices,thus forming a star.

    Advantages:

1. If one nodes fails, only that nodes is affected.
2. Nodes can be added or removed from network with no disruption.

    Disadvantages:

1. If the hub or switch fails , the entire network will be inoperable.
2. Expensive to set up due to the cost of hub/switch.

      Ring Network Topology:

 

http://swissen.in/ringtopology.php

•  On a ring network, a cable form a closed loop ( ring) with all computers and nodes arranged along the ring.

      Advantages:

1. All nodes in ring topology share the network resources fairly.
2. Transmission of data is simple as packets travel in one direction only.

   Disadvantages:

1. If one node fails it can take down entire network.
2. More difficult to install than a bus network.

          Classification of network:

  Local Area Network:

• is a network that connects computers and devices in a limited geographical area.
• Example, home and network in cyber cafe.

http://www.omnisecu.com/basic-networking/lan-and-wan-local-area-network-and-wide-area-network.php

  Advantages:

1. Easy to share devices.
2. Easy to share data.

  Disadvantages:

1. Security problem because exposed to viruses and hackers.
2. Area covered is limited.

   Metropolitan Area Network (MAN).

• Is a high-speed network that connects local area networks in a metropolitan area.
• Example city or town.

http://www.certiology.com/computing/computer-networking/types-of-networks.html

    Advantages:

1. Efficiency and shared access.
2. All the computer-owning residents of the area have equal ability to go online.

    Disadvantages:

1. Security problem because exposed to viruses and hackers.

     Wide Area Network (WAN)

• Is a network that covers a large geographic area ( such as a city,country, or a world) using a variety of wired and wireless transmission media.

http://computeroperatornepal.blogspot.my/2015/08/types-of-computer-network.html   

    Advantages:

1. Messages can be sent very quickly to anyone else on the network.
2. Share information/files over a large area.

    Disadvantages:

1. Security problems because exposed to viruses and hackers.