Basics of Data Communication & Networking: Transmitting Data & Connecting Devices, Lecture notes of Data Communication Systems and Computer Networks

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COMMUNICATION AND

NETWORKING

COMMUNICATION AND NETWORKING

Data communications refers to the transmission of this digital data between two or more computers and a computer network or data network is a telecommunications network that allows computers to exchange data. The physical connection between networked computing devices is established using either cable media or wireless media. The best-known computer network is the Internet.

COMMUNICATION AND NETWORKING

This module should teach you basics of Data Communication and Computer Network (DCN) and will also take you through various advanced concepts related to Data Communication and Computer Network.

COMMUNICATION AND NETWORKING

Data communication refers to the exchange of data between two or more devices via a transmission medium.

Networking involves connecting multiple devices to facilitate communication and resource sharing.

The purpose of data communication and networking is to enable the efficient transfer of information.

COMMUNICATION

Data communication is the process of transmitting data or information from one point to another through a communication medium.

In the modern digital era, data communication has become an integral part of our daily lives and is crucial for businesses, organizations, and individuals to exchange information, collaborate, and access resources over networks.

COMMUNICATION

Key Concepts of Data Communication:

Data: Data refers to the raw and unprocessed facts, figures, or symbols that represent information.

Communication: Communication is the exchange of data or information between devices or entities using a common set of rules or protocols.

COMMUNICATION

…Data Transmission: Data transmission involves sending data from the source to the destination over a communication channel or medium.

Communication Medium: The communication medium is the physical path or channel through which data is transmitted, such as wired cables, fiber optics, or wireless radio waves.

COMMUNICATION

Components of Data Communication: Sender: The device that initiates the data communication process and generates the data to be transmitted. Receiver: The device that receives the data sent by the sender and processes it. Transmission Medium: The physical path through which data is transmitted, such as copper wires, fiber optics, or wireless channels. Message: The information or data being transmitted from the sender to the receiver. Protocol: The set of rules and procedures governing the format and transmission of the message.

COMMUNICATION

Characteristics of Data Communication:

Speed: The rate at which data is transmitted, usually measured in bits per second (bps) or megabits per second (Mbps).

Accuracy: The extent to which the transmitted data remains uncorrupted and error-free.

Reliability: The degree to which data transmission is consistent and free from failures or disruptions.

COMMUNICATION

Security: Measures taken to protect data from unauthorized access or tampering during transmission.

Scalability: The ability of a communication system to accommodate an increasing number of users or devices.

Compatibility: The ability of different devices and systems to work together and exchange data seamlessly.

COMMUNICATION

Standards

Standards are established guidelines, specifications, or criteria that serve as a basis for ensuring uniformity, interoperability, safety, and efficiency in various industries, products, systems, and processes. They play a crucial role in promoting innovation, supporting global trade, and enhancing quality and safety standards. Standards can be classified into different types based on their application and scope.

COMMUNICATION

International Standards Organisation (ISO)

ISO (International Organization for Standardization):

ISO is an international standard-setting body that develops and publishes standards covering various aspects of technology, industry, and commerce.

It is a non-governmental organization with a membership of national standards bodies from more than 160 countries.

COMMUNICATION

ISO standards are developed through a consensus-based process involving experts from different industries and countries.

ISO standards aim to promote global interoperability, quality, safety, and efficiency in products, services, and systems across various sectors.

Some well-known ISO standards include ISO 9001 for quality management systems, ISO 14001 for environmental management systems, ISO 27001 for information security management, and ISO 3166 for country codes, among many others.

COMMUNICATION

Communication standards are established sets of rules, protocols, and specifications that ensure interoperability, consistency, and seamless communication between various devices, systems, and networks. These standards are critical for enabling reliable data exchange and efficient communication in both wired and wireless environments. There are numerous communication standards developed by various standardization organizations, industry consortia, and governing bodies.

COMMUNICATION

OSI (Open Systems Interconnection) Model:

The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven distinct layers.

It was developed by the International Organization for Standardization (ISO) in the late 1970s and published in 1984 as ISO 7498-1.

COMMUNICATION

…The OSI model aims to promote interoperability between different network protocols and technologies by defining clear interfaces and responsibilities for each layer.

Each layer of the OSI model performs specific functions, and communication between devices relies on standardized protocols and data formats.

The seven layers of the OSI model, from the bottom to the top, are: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

COMMUNICATION

The OSI (Open Systems Interconnection) model is a conceptual framework used to understand and describe how different networking protocols and technologies interact and communicate within a network. It consists of seven layers, each with specific responsibilities and functions. The OSI model helps in the development of network protocols, ensuring interoperability and modular design.

COMMUNICATION AND NETWORKING

Layer 7: Application Layer:

The Application Layer is the topmost layer and provides network services directly to end-users or applications.

It enables communication between different software applications and interacts with users.

Examples of application layer protocols include HTTP (Hypertext Transfer Protocol), FTP (File Transfer Protocol), SMTP (Simple Mail Transfer Protocol), and DNS (Domain Name System).

COMMUNICATION AND NETWORKING

Layer 6: Presentation Layer:

The Presentation Layer is responsible for data representation, encryption, and compression.

It ensures that data is properly formatted and compatible between different systems.

Examples of presentation layer functions include data encryption/decryption, character encoding, and compression/decompression.

COMMUNICATION AND NETWORKING

Layer 5: Session Layer:

The Session Layer establishes, maintains, and terminates sessions between applications on different devices.

It manages communication sessions, synchronization, and data exchange between applications.

Examples of session layer functions are session establishment, data synchronization, and dialogue control.

COMMUNICATION AND NETWORKING

Layer 4: Transport Layer:

The Transport Layer provides end-to-end communication between devices and ensures reliable and error-free data transfer.

It segments data into smaller packets, adds sequence numbers, and handles flow control and error recovery.

Examples of protocols used at this layer include TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).

COMMUNICATION AND NETWORKING

Layer 3: Network Layer:

The Network Layer deals with logical addressing and routing of data packets from the source to the destination across multiple networks.

It uses IP (Internet Protocol) addresses to identify devices on the network and determines the best path for data delivery.

Examples of protocols used at this layer include IP (IPv4 and IPv6), ICMP (Internet Control Message Protocol), and OSPF (Open Shortest Path First).

COMMUNICATION AND NETWORKING

Layer 3: Network Layer:

The Network Layer deals with logical addressing and routing of data packets from the source to the destination across multiple networks.

It uses IP (Internet Protocol) addresses to identify devices on the network and determines the best path for data delivery.

Examples of protocols used at this layer include IP (IPv4 and IPv6), ICMP (Internet Control Message Protocol), and OSPF (Open Shortest Path First).

COMMUNICATION AND NETWORKING

Layer 2: Data Link Layer:

The Data Link Layer provides reliable data transfer between two directly connected devices over a physical link.

It is responsible for framing data into frames, adding MAC (Media Access Control) addresses, and performing error detection and correction.

Divided into two sub-layers: Logical Link Control (LLC) and Media Access Control (MAC).

Examples of protocols used at this layer include Ethernet, Wi-Fi (802.11), and PPP (Point-to-Point Protocol).