Network its types benefits and Network Topology

 Network its types benefits and Network Topology

What are computer network. What are information network, describe its types in detail.

Computer Network

            Sharing of data and resources in a secure and reliable way by using fastest communication channels is called network. Two or more computers are connected together with each other by using any communication channel to share their data and resources like printer, hard disk, software, internet, scanner files. Standalone computer cannot work more effectively as compare with networked environment. Sharing of data and resources is direly needed by all the routine matters.

Benefits of Network

Today computer and other networks are playing very important role in exchange or information from one place to another place. Maximum benefits can only be achieved when information is transmitted all over the world easily and quickly for the benefit of the community. Due to the rapid advancement in communication channels the vital source of information can be transmitted and interpreted very easily and swiftly between different departments, organizations, universities and research centers. Due to digital convergence many organizations are using many resources of information collected by some other organizations.

Today information networks, cellular networks, banking networks and merging of organization has make our business and other transactions very easy. Universities are providing online enrollment, examination, result information sources. Banks are providing online transactions to transfer amount from one city or country to another country and bank. we can make transactions from our house and can transfer amount and view our bank statement. Hotels, restaurants, airlines, railways are also using the benefits of network to reserve tickets and other processing.

Architecture of Computer Network

Peer to peer                                         

Client Server

Decentralized     

Centralized

Work Group                                        

Domain Based

In client server architecture, server is the main computer to manage all the clients computer/nodes over the network. It also manages all the resources and clients will send all the requests to the server. All the resources are distributed from the server to the clients. Data, programs and resources will be shared by the clients.

In workgroup environment all the computers are using their own resources. There is no central or main computer to control the clients. All the computers are called peer in this type of network. There is no sharing of data and programs.

There are 3 types of network.

LAN, WAN, MAN.

LAN

LAN stands for local area network. This type of network is installed in a single building or some contiguous buildings but having single network id. The entire computer can be connected by wire or wireless media to make communication possible. This type of network is used for short distance communication. A network of a bank branch, a university/ college campus is an example of LAN. Almost all the offices use LAN to make communication possible to share their resources and data. LAN card or NIC (Network interface Card), Hub, cables, connectors, servers are used in LAN.

MAN

MAN stands for Metropolitan Area Network. This type of network is used to connect different LANs but within the area of the city. Different LANs with different networks id are connected with each other to share their local in-office information to the other offices and LANs. For example different branches (LANs) of banks are connected with each other within the geographical area of a city to exchange their information. Wireless, fiber optic, leased lines are used to install that type of network. It plays very important role to share information with in LAN of an organization and different organizations. NIC (Network interface Card), hub, switches, cables, connectors and special computers called servers are used in MAN. Network software also used to facilitate the users of the network. Print servers, database servers, DNS (domain name server) & ADS (active directory services server) servers and DHCP (dynamic host configuration protocol) protocols are used.

WAN

WAN stand for Wide Area Network. We can share information all over the world. Different LANs and MANs are connected together for the exchange of information from any place. Internet is the example of WAN. Any type of information can be obtained from any part of the world. Different organizations provide different applications to spread information for the general public. We can use our bank account globally and debit and credit card are used and this benefit can only be achieved by WAN.

Multinational companies, banks, universities and many other organizations provide their service globally and we can benefited by WAN.

We can download different software and many other resources. We can purchase many things online from any part of the country. Different communication software is used to make communication possible. NIC (Network interface Card), Hub, switches, routers, cables, connectors, web servers, FTP servers (file transfer protocol), HTTP servers (hyper text transfer protocol), File Server, Print Server, DNS(domain name server) & ADS (active directory services server) servers and DHCP(dynamic host configuration protocol) protocols are used in this type of network.

What is Network Topology? Describe its types in detail

The physical layout of a network is called topology. The order in which computers are physically connected with cable and cable is directly connected to other computer or hub/switch. Topology actually describes the network cabling and the way of communication that is direct or indirect. network is used to share our data and resources in a secure and reliable way and communication channel should be reliable and fast to transmit maximum data in time as well as there should minimum error ratio. There are 4 or 5 types of topologies. Bus, Star, Tree, Ring Mesh Topology.

Bus Topology

This topology is used where are few numbers of computer. All the computers are connected by using a single central cable. This topology is used for very small network of short distance and for 5 to 10 computers. It is easy to install and less expensive. Coaxial cable is used for bus topology. Currently this topology is not in use commonly. In this network computers are called nodes. It central cable is disconnected or damage the whole network will be jammed. This topology is not very stable and reliable. This topology is only used in LANs of very short distance. Message is sent to the computer with its id

Star Topology

This topology is commonly used in LANs. In this type of network a communication device called hub is used to connect the computers to make communication possible. Hub is also called multi port repeater. It has 8 16 or 24 ports. Each computer connects with the hub by a dedicated single cable. All the ports in the hub are internally connected with each other in the shape of a star. Hub receives the message or signals from the sender/transmitter computer and then boosts up the signal and transmits it to the target/receiver computer. Signal can not be weak due to the multi port repeater hub. it one cable of the computer is damaged then single computer will be disconnected from the network rest of the network will work properly. Number of computer in this network can be increased easily and quickly. UTP (unshielded twisted pair) STP (shielded twisted pair) cable is used in this network. LAN card, NIC and RJ 45 connectors are used in this topology. Installation, maintenance and trouble shooting in this topology are easy. CSMA/CD object is used in this type of topology to get avoid from dead lock.

Tree Topology

Tree topology is combination of many star networks. When we have to expand our star network then we use multiple hubs that are interconnected with each other and all the computers are connected with each other. This is actually connection of star topology to support large number of computer in a network.

Ring Topology

This topology is used where server computer are connected for synchronization of data. Database servers and web servers are linked together to synchronize and share their data and resources. Servers are multiplexed on different locations for the security purposes and make availability of data easy to the clients from the server. Different servers are located in different places and clients can connect to their local server. These servers are connected by using ring topology and each server has the address of its backward and forward computer. If we have to add or remove computer from this topology then we must have to reassign these addresses to the computers, so addition and deletion of computer in this topology is difficult and time consuming. Routers, switches, DNS servers are used in this type of network. A special signal called token is used in this topology. When the token is free then any computer can send data on the network by using this token.

Mesh Topology

In mesh topology each computer in network is directly connected to each computer. Every two computers have their directed dedicated cable to make communication possible between them. The design of mesh topology provides high level of performance and less error chances. It is used at high level of communication systems. It is very expensive and not easy to install.