2. Unit No: I
Introduction to Computer Networking
Fundamentals
• A computer network is a collection of interconnected devices that
share resources and information.
• These devices can include computers, servers, printers, and other
hardware.
• Networks allow for the efficient exchange of data, enabling various
applications such as email, file sharing, and internet browsing.
3. Basic Terminologies of Computer Networks
• Network: A network is a collection of computers and devices that are
connected together to enable communication and data exchange.
• Nodes: Nodes are devices that are connected to a network. These can include
computers, Servers, Printers, Routers, Switches, and other devices.
• Protocol: A protocol is a set of rules and standards that govern how data is
transmitted over a network. Examples of protocols include TCP/IP, HTTP, and FTP.
• Topology: Network topology refers to the physical and logical arrangement of
nodes on a network. The common network topologies include bus, star, ring,
mesh, and tree.
4. Continue..
• Service Provider Networks : These types of Networks give permission to
take Network Capacity and Functionality on lease from the Provider. Service
Provider Networks include Wireless Communications, Data Carriers, etc.
• IP Address : An IP address is a unique numerical identifier that is assigned to
every device on a network. IP addresses are used to identify devices and enable
communication between them.
• DNS : The Domain Name System (DNS) is a protocol that is used to translate
human-readable domain names (such as www.google.com) into IP addresses that
computers can understand.
• Firewall : A firewall is a security device that is used to monitor and control
incoming and outgoing network traffic. Firewalls are used to protect networks
from unauthorized access and other security threats.
5. Working of Computer Network
• Basics building blocks of a Computer network are Nodes and Links. A
Network Node can be illustrated as Equipment for Data
Communication like a Modem, Router, etc., or Equipment of a Data
Terminal like connecting two computers or more.
• Link in Computer Networks can be defined as wires or cables or free
space of wireless networks.
• The working of Computer Networks can be simply defined as rules or
protocols which help in sending and receiving data via the links which
allow Computer networks to communicate.
• Each device has an IP Address, that helps in identifying a device.
6. Overview of data transmission systems
• Transferring data over a transmission medium between two or more
devices, systems, or places is known as data communication.
• Nowadays, computing and telecommunications depend heavily on
this data transmission, which makes a variety of applications
conceivable, including email, video chatting, the Internet, and many
more things.
7. Components of Data Communication
A communication system is made up of the following components:
Message:
• The most essential component of a data communication system is the message. A message refers to the data or
information that needs to be transmitted. It can take various forms, such as a text document, an audio recording, a video
file, or any other type of digital content.
Sender:
• To transfer message from source to destination, someone must be there who will play role of a source. Sender plays part of
a source in data communication system. It is simple a device that sends data message. The device could be in form of a
computer, mobile, telephone, laptop, video camera, or a workstation, etc.
Receiver:
• The receiver is the destination where the message sent by the source ultimately arrives. It is the device that receives the
message. Like the sender, the receiver can also be a computer, mobile phone, telephone, workstation, or any other
communication device."
Transmission Medium / Communication Channels:
• In the entire data communication process, a medium is required to connect the sender and the receiver—this role is
fulfilled by the transmission medium. It is the physical path through which data or messages travel from the sender to the
receiver. The transmission medium can be guided (using wires) or unguided (wireless). Examples include twisted pair
cables, fiber optic cables, radio waves, and microwaves."
9. • Set of rules (Protocol):
When data is sent by the sender, it must be in a form that the receiver can understand—otherwise, the
communication becomes meaningless.
For example, if Sonali sends a message to Sunita in Hindi, but Sunita doesn't understand Hindi, the message
loses its value, and effective communication fails."
10. • There are some set of rules (protocols) that is followed by every
computer connected to the internet and they are:
TCP(Transmission Control Protocol):
It is responsible for dividing messages into packets on the source computer and
reassembling the received packet at the destination or recipient computer.
It also makes sure that the packets have the information about the source of the
message data, the destination of the message data, the sequence in which the
message data should be re-assembled, and checks if the message has been sent
correctly to the specific destination.
