Topics Covered
- Computer Network – Introduction, Data Communication, Needs of Computer Networks, Advantages & Disadvantages of Network, Network Terminology, Node, Workstation, Server, Types of Server, Dedicated and Non-Dedicated Server, NIC, MAC Address, and IP Address
- Types of network: LAN, MAN, WAN, PAN, LAN vs WAN
- Networking Devices: Modem, Hub, Repeater, Switch, Bridge, Gateway
- Network Topology: Point to Point, Bus, Star, Ring, Mesh, Hybrid
Introduction to network
Network / Computer Networks
The collection of interconnected computers is called a computer network.
A computer network is a logical or physical interconnection between two or more computers such that they could communicate with each other.
Data Communication
Two computers are said to be interconnected if they are capable of sharing and exchanging information. The process of transferring data between computers is known as data communication.
Needs of Computer Networks
- Resource Sharing – Resource Sharing means to make all programs, data, and peripherals available to anyone on the network irrespective of the physical location of the resources and the user.
- Reliability – Reliability means to keep the copy of a file on two or more different machines, so if one of them is unavailable (due to some hardware crash or any other) then its other copy can be used.
- Cost Factor – The cost factor means it greatly reduces the cost since the resources can be shared.
- Communication Medium – Communication Medium means one can send messages and whatever the changes at one end are done can be immediately noticed at another.
Application of Networks
- Sharing of data, services, and resources
- Access to a remote database
- Communication facilities
Advantages of Computer Network
- The Computers on the Network can share hardware devices like printers, scanners, etc.
- Data and software can be shared within the computer on the network.
- Files can be transferred from one computer to another computer.
- Computers in the network can communicate with each other.
Disadvantages of Computer Network
- Data and information may be stolen by computer hackers.
- If any computer in the network gets affected by the virus, there is a high chance of spreading a computer virus.
- Computers on the network have to depend on the server.
Terminology of Networks
Nodes / Workstations – The term nodes refer to the computers that are attached to a network and are seeking to share the resources.
Server – A computer that facilitates the sharing of data, software, and hardware resources on the network, is called Server. A network can have more than one server also. Each server has a unique name on the network and all users of the network identify the server by its unique name.
Types of Server
There are two types of servers:-
(a) Non-dedicated –
A workstation, that can work as a Server is also, called a Non-dedicated server, It can facilitate resource-sharing. It is slower and requires less memory. Networks with a non-dedicated server are known as PEER-TO-PEER networks.
(b) Dedicated server –
A Computer, specially reserved for the Server purpose, is called Dedicated Server. Its only job is to help workstations access data, software, and hardware resources. Networks with Dedicated server is known as MASTER-SLAVE networks.
File Server – storing files, controlling access and amount of storage for users.
Printer Server – takes care of the printing requirement.
Modem Server – helps a group of network users use a modem to transmit long-distance messages.
Network Interface Unit (NIU) / MAC Address
A network interface unit is a device (network card) / interpreter that helps in establishing the communication between the server and the client.
Network interface Unit, has a unique number to identify the node/workstation, called Node address. The NIC manufacturer assigns a unique physical address to each NIC card, known as the Media Access Control address (MAC Address). MAC address is a 6-bytes address with each byte separated by a colon(:). It has two parts – Manufacturer ID (First 3 bytes) and Card No(Next 3 bytes).
Example :=> AB : 8C : 32 : 89 : B4 : 6E
manufacturer id card-no
MAC address is unique for each network card. To check your computer MAC address, do the following: –
Open cmd (Command Prompt),
type ipconfig or ipconfig/all, and press enter key.
IP Address
A set of rules are called Protocols. TCP/IP is the most common networking protocol, which follows by the Internet also.
Every computer on TCP/IP network has a unique identifying number, called an IP address. IP addresses are needed so that different networks can communicate with each other. Each IP address is actually a series containing four numbers separated by dots or periods e.g. 192.168.100.10 . IP addresses are normally written in dotted decimal form
IPv4 address – an older version of IP address is 32-bit long.
IPv6 address – a newer version of IP address is 128-bit long.
Example
2001 : 0db8 : 85a3 : 0000 : 0000 : 8a2e : 0370 :7334 (each group is 16 bits long)
