NETWORK..!!

Hey min'na !

Today I want to share to all my reader about network. Network basic is the first topic the I learn in subject computer science in this semester.

Network is the collection of the computers & devices that connected 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 others routers together & transmit data to its correct destination on a network.

2. Dial-up Modem

• A communication device that can convert digital signals to analog signal & 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 & 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 & devices to transfer data wireless among themselves or to transfer data wireless to a wire network using wireless technologies such as wi-fi.

Two Types 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
• Satelite

NETWORK ARCHITECTURE

(design of computers, devices & media in a network)

Client/Server

• A client/server network is a network in which the shared files & applications are in the server but network users (client) can still store files on their individual PC's. A server is a computer that shares information & resources with other computers on a network. A client is a computer which request services or files from a server computer.

Peer-To-Peer

• Peer-to-peer network is a network with all the nodes acting as both servers & clients. A PC can access another PC & can also provides files to other PC's. With peer-to-peer network no server is needed each computer in the network is called a peer. All computers in the peer-to-peer network has equal responsibilities to use the resources available on the network.

NETWORK TOPOLOGY

(a network topology refers to the layout of the computers & devices in a communications network)

3 types of network topology :

• Ring Topology

A network topology that is set up in a circular fashion in which data travels around the ring in one direction & each device on the ring acts as a repeater to keep the signal strong as it travels. Each device incorporates a receiver for the incoming signal & a transmitter to send the data on to the next device in the ring. The network is dependent on the ability of the signal to travel around the ring. When a device sends data, it must travel through each device on the ring until it reaches its destination. Every node is a critical link. In a ring topology, there is no server computer present. All nodes work as a server & repeat the signal. The disadvantage of this topology is that if one node stops working, the entire network is affected or stops working.

• Star Topology

In local area networks with a star topology, each network host is connected to a central hub with a point-to-point connection. In Star topology every node (computer workstation or any other peripheral) is connected to a central node called hub or switch. The switch is the server & the peripherals are the clients. The network does not necessarily have to resemble a star to be classified as a star network, but all of the nodes on the network must be connected to one central device. All traffic that traverses the network passes through the central hub. The hub acts as a signal repeater. The star topology is considered the easiest topology to design and implement. An advantage of the star topology is the simplicity of adding additional nodes. The primary disadvantage of the star topology is that the hub represents a single point of failure.

• Bus Topology

In local area networks where bus topology is used, each node is connected to a single cable. Each computer or server is connected to the single bus cable. A signal from the source travels in both directions to all machines connected on the bus cable until it finds the intended recipient. If the machine address does not match the intended address for the data, the machine ignores the data. Alternatively, if the data matches the machine address, the data is accepted. Because the bus topology consists of only one wire, it is rather inexpensive to implement when compared to other typologies. However, the low cost of implementing the technology is offset by the high cost of managing the network. Additionally, because only one cable is utilized, it can be the single point of failure.