IRIS EDUCATION

Network Security While working on a network, a computer can be accessed by many users. It is important to protect the network from unauthorised access and prevent the loss or  misuse of data or information. It is important to ensure that only authorized person access or modify data. Protecting data and resources from unauthorised access is known as network security. There are two general levels of network security. They are: Login Security It is important to give a unique login name and password to every person on the network. Rights security Based upon your username you are given the rights like Read-Only Access or Read-Write Access. A combination of rights can also be granted to the same user for network security.

Network Topology The approach of connecting different computers in a network is known as Topology. Network topology is an arrangement of layout in which various computers are connected to one another. On the basis of network topology, network can be classified into five main types: Bus Topology Ring Topology Star Topology Mesh Topology Tree Topology Bus Topology In Bus Topology a single cable known as backbone or bus carries all the data (traffic). Communication travels in both the directions along the line, and can be received by any node. All the computers, printers and other peripheral devices that are being shared are connected to the bus.  This topology is normally used for small network. Advantages:- Failure of any computer or device does not affect others. It is easy to install and economical, as it consumes a single communication cable. A new PC can be easily connected to the existing network with just a short cable. Disadvantages:- ...

Transmission Media Transmission media means to send the data from one place to another place through some medium like wire or wireless. The transmission media or medium can be classified into two categories Wired Transmission Media and Wireless Transmission Media. Wired Transmission Media Wired transmission media or medium uses wires or cables to transmit data from one place to another place. In this type of medium we use wires or cables. The data is transferred in the form of electrical or light signal. There are various types of cables that can be used for setting up a network. Some of them are as follows: Twisted Pair Cable Twisted pair cable was invented by Alexander Graham Bell in 1881. It is the most widely used medium for telecommunication. It consists of copper wires that are twisted into pairs. An ordinary telephone wire consists of two insulated copper wires twisted into pairs. Computer networking cables consists of four pair of copper wire that c...

Computer Architecture and Networks Types of Computer Networks There are various types of computer network which are widely used. These networks are classified according to the geographical area coverage. Basically there are four types of computer networks: Personal Area Network (PAN) – A PAN is a computer network which is connected around a person. It is used to communicate between devices like printers, phones, etc. Local Area Network (LAN) – In LAN two or more computers and peripheral devices are connected within a small area such as room, an office building, etc. In LAN computer terminals are physically connected with wires. Metropolitan Area Network (MAN) – A MAN is a network which covers more area than a LAN. It spreads across a city that is why it is called Metropolitan area network. Cable TV, Telephone Networks, etc. are some common example of MAN. Wide Area Network (WAN) – A wide area network is a telecommunication network that spread across cities, count...

Components of a network Component means parts, through which the network is made up of, some of them are: Modem – Modem is a device which helps the computer to send the data over networks. Usually the data is transmitted from one place to another place in the form of analog signal, but the computer processes digital data so the modem helps to convert this digital data into analog signal and send this data through telephone line or with the help of some other media. The word modem is derived from the term modulator and demodulator which mean to modulate the digital signal to analog signal and demodulate the analog to digital signal. Network Interface Card – A network interface card connects your computer to a network or the Internet. It is a circuit board installed in a computer. It is also called network interface controller, network adapter or LAN adapter. We connect to network with a unique id called MAC id (Media Access Control), we get this MAC id from the ROM chip which is ...

Types of Network Protocol Network protocols are formal rules, procedures and formats that define communication between two or more devices over a network. Network protocols govern the end to end process of network communication. There are wide ranges of protocol used in network communication some are given below: File Transfer Protocol (FTP) – The File Transfer Protocol or FTP is a protocol used for transferring files from one computer to another computer. FTP is the preferred method of exchanging files because it is faster than other protocols like HTTP (Hyper Text Transfer Protocol) or POP (Post Office Protocol). Simple Mail Transfer Protocol (SMTP) – This protocol is used for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another. The messages can then be retrieved with an e-mail client using either POP or IMAP . POP is the short form of Post Office Protocol, a protocol used t...