Introduction HILI subcommittee (IEEE802.1) of the IEEE identified the following possible internetworking scenarios. A single LAN Two LANs connected together (LAN-LAN) A LAN connected to a WAN (LAN-WAN) Two LANs connected through a WAN (LAN-WAN-LAN) Various internetworking devices such as hubs, bridges, switches, routers and gateways are required to link them together. RJ-45 RJ-45 , […]
Data Communication and Networking Tutorials and Study Notes
Before Moving Ahead with the Data Communication And Networking tutorials, Lets have a look at what we will learn in these Topics.
Data communication refers to the exchange of digital information between two or more devices through a transmission medium, such as a wired or wireless network. Networking, on the other hand, is the process of connecting these devices together to enable data communication.
In today’s digital age, data communication and networking are crucial to our daily lives. They allow us to send and receive information quickly and efficiently, which has revolutionized the way we work, communicate, and access information. For example, we use data communication and networking to send emails, stream videos, make phone calls, and browse the internet.
In learning about data communication and networking, we will explore topics such as network architecture, protocols, routing, wireless communication, and security. We will also examine different types of networks, including LANs, WANs, and the Internet.
Understanding data communication and networking is important for several reasons. First, it helps us to troubleshoot and fix network-related issues. Second, it enables us to design and implement efficient and secure networks. Finally, it provides us with the knowledge necessary to stay safe online and protect our personal and sensitive information.
Overall, data communication and networking are fundamental to our modern world, and learning about them is essential for anyone interested in technology or pursuing a career in the field.
At the end of a data communication and networking learning journey, you will have gained a comprehensive understanding of how information is transmitted and exchanged between different devices and networks.
You will have learned about the fundamentals of data communication, including the various components involved in the process, such as protocols, data transmission media, and network topologies.
You will also have learned about different networking concepts, such as LANs, WANs, and the Internet, as well as the basics of network architecture and design.
Additionally, you will have gained an understanding of the various protocols and technologies used in networking, such as TCP/IP, Ethernet, Wi-Fi, and DNS.
Other topics you may cover during your learning journey could include network security, network management, network performance optimization, and cloud networking.
Overall, the knowledge and skills gained during a data communication and networking learning journey are crucial for professionals in various fields, including network administration, cybersecurity, software development, and more.
Specifically, you will learn about:
Introduction In the early 1970’s there were many data communication networks (also known as Public Networks), which were owned by private companies, organizations and governments agencies. Since those public networks were quite different internally, and the interconnection of networks was growing very fast, there was a need for a common network interface protocol. In 1976 […]
DATA COMMUNICATION AND NETWORK CONCEPTS Network The collection of interconnected computers is called acomputer network. Two computers are said to be interconnected if they are capable of sharing and exchanging information. Need Resource Sharing Reliability Cost Factor Communication Medium Resource Sharing means to make all programs, data and peripherals available to anyone on the network […]
Network Security Concepts Viruses Viruses are programs which replicate and attach to other programs in order to corrupt the executable codes. Virus enters the computer system through an external source and become destructive. Worms Worms are also self- replicating programs that do not create multiple copies of itself on one computer but propagate through the […]
The International Standards Organization created a model called the Open Systems Interconnection, which allows diverse systems to communicate. The seven-layer OSI model provides guidelines for the development of universally compatible networking protocols. The physical, data link, and network layers are the network support layers. The session, presentation, and application layers are the user support layers. […]
Data must be transformed to electromagnetic signals to be transmitted. Data can be analog or digital. Analog data are continuous and take continuous values. Digital data have discrete states and take discrete values. Signals can be analog or digital. Analog signals can have an infinite number of values in a range; digital ,signals can have […]
Digital-to-digital conversion involves three techniques: line coding, block coding, and scrambling. Line coding is the process of converting digital data to a digital signal. We can roughly divide line coding schemes into five broad categories: unipolar, polar, bipolar, multilevel, and multitransition. Block coding provides redundancy to ensure synchronization and inherent error detection. Block coding is […]
Digital-to-analog conversion is the process of changing one of the characteristics of an analog signal based on the information in the digital data. Digital-to-analog conversion can be accomplished in several ways: amplitude shift keying (ASK), frequency shift keying (FSK), and phase shift keying (PSK). Quadrature amplitude modulation (QAM) combines ASK and PSK. In amplitude shift […]
OPEN SYSTEMS INTER CONNECTION REFERENCE MODEL (OSIRM ) Introduction to OSI Model & its layers The Open Systems Interconnection (OSI) Model was developed by International Organization for Standardization (ISO). ISO is the organization, OSI is the model It was developed to allow systems with different platforms to communicate with each other. Platform could mean hardware, software or operating system. […]
Bandwidth utilization is the use of available bandwidth to achieve specific goals. Efficiency can be achieved by using multiplexing; privacy and antijamming can be achieved by using spreading. Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single data link. In a multiplexed system, n lines share the […]
Transmission Medium A transmission medium (plural media) is one which carries a signal from one computer to another. It is also known as communication channel. Transmission medium can be wired or wireless. Wired Transmission Media The data signal physically gets transferred from the transmitting computer to the receiving computer through the wired transmission medium. Some […]
A switched network consists of a series of interlinked nodes, called switches. Traditionally’ three methods of switching have been important: circuit switching, packet switching, and message switching. We can divide today’s networks into three broad categories: circuit-switched networks, packet-switched networks, and message-switched. Packet-switched networks can also be divided into two subcategories: virtual-circuit networks and datagram […]
The telephone, which is referred to as the plain old telephone system (POTS), was originally an analog system. During the last decade, the telephone network has undergone many technical changes. The network is now digital as well as analog. The telephone network is made of three major components: local loops, trunks, and switching offices. It […]
Data can be corrupted during transmission. Some applications require that errors be detected and corrected. In a single-bit error, only one bit in the data unit has changed. A burst error means that two or more bits in the data unit have changed. To detect or correct errors, we need to send extra (redundant) bits […]
Data link control deals with the design and procedures for communication between two adjacent nodes: node-to-node communication. Framing in the data link layer separates a message from one source to a destination, or from other messages going from other sources to other destinations, Frames can be of fixed or variable size. In fixed-size framing, there […]
Data communications are the transfer of data from one device to another via some form of transmission medium. A data communications system must transmit data to the correct destination in an accurate and timely manner. The five components that make up a data communications system are the message, sender, receiver, medium, and protocol. Text, numbers, […]
Multiple Access Protocol We can consider the data link layer as two sublayers. The upper sublayer is responsible for data link control, and the lower sublayer is responsible for resolving access to the shared media. Many formal protocols have been devised to handle access to a shared link. We categorize them into three groups: random […]
Ethernet is the most widely used local area network protocoL The IEEE 802.3 Standard defines I-persistent CSMA/CD as the access method for first-generation 10-Mbps Ethernet. The data link layer of Ethernet consists of the LLC sublayer and the MAC sublayer. The MAC sublayer is responsible for the operation of the CSMAlCD access method and framing. […]
The IEEE 802.11 standard for wireless LANs defines two services: basic service set (BSS) and extended service set (ESS). The access method used in the distributed coordination function (OCF) MAC sublayer is CSMAICA. The access method used in the point coordination function (PCF) MAC sublayer is polling. The network allocation vector (NAV) is a timer […]
A repeater is a connecting device that operates in the physical layer of the Internet model. A repeater regenerates a signal, connects segments of a LAN, and has no filtering capability. A bridge is a connecting device that operates in the physical and data link layers of the Internet model. A transparent bridge can forward […]
Cellular telephony provides communication between two devices. One or both may be mobile. A cellular service area is divided into cells. Advanced Mobile Phone System (AMPS) is a first-generation cellular phone system. Digital AMPS CD-AMPS) is a second-generation cellular phone system that is a digital version of AMPS. Global System for Mobile Communication CGSM) is […]
Synchronous Optical Network (SONET) is a standard developed by ANSI for fiber-optic networks: Synchronous Digital Hierarchy (SDH) is a similar standard developed by ITU-T. SONET has defined a hierarchy of signals called synchronous transport signals (STSs). SDH has defined a similar hierarchy of signals called synchronous transfer modules (STMs). An OC-n signal is the optical […]
Virtual-circuit switching is a data link layer technology in which links are shared. A virtual-circuit identifier (VCI) identifies a frame between two switches. Frame Relay is a relatively high-speed, cost-effective technology that can handle bursty data. Both PVC and SVC connections are used in Frame Relay. The data link connection identifier (DLCI) identifies a virtual […]
At the network layer, a global identification system that uniquely identifies every host and router is necessary for delivery of a packet from host to host. An IPv4 address is 32 bits long and uniquely and universally defines a host or router on the Internet. In classful addressing, the portion of the IP address that […]
IPv4 is an unreliable connectionless protocol responsible for source-to-destination delivery. Packets in the IPv4 layer are called datagrams. A datagram consists of a header (20 to 60 bytes) and data. The maximum length of a datagram is 65,535 bytes. The MTU is the maximum number of bytes that a data link protocol can encapsulate. MTUs […]
Delivery of a packet to a host or router requires two levels of addresses: logical and physical. A physical address identifies a host or router at the physical level. Mapping of a logical address to a physical address can be static or dynamic. Static mapping involves a list of logical and physical address correspondences; maintenance […]
The delivery of a packet is called direct if the deliverer (host or router) and the destination are on the same network; the delivery of a packet is called indirect if the deliverer (host or router) and the destination are on different networks. In the next-hop method, instead of a complete list of the stops […]
In the client/server paradigm, an application program on the local host, called the client, needs services from an application program on the remote host,’ called a server. Each application program has a port number that distinguishes it from other programs running at the same time on the same machine. The client program is assigned a […]
The average data rate, peak data rate, maximum burst size, and effective band width are qualitative values that describe a data flow. A data flow can have a constant bit rate, a variable bit rate, or traffic that is bursty. Congestion control refers to the mechanisms and techniques to control congestion and keep the load […]
IP Security (IPSec) is a collection of protocols designed by the IETF (Internet Engineering Task Force) to provide security for a packet at the network level IPSec operates in the transport mode or the tunnel mode. In the transport mode, IPSec protects information delivered from the transport layer to the network layer. IPSec in the […]
The Domain Name System (DNS) is a client/server application that identifies each host on the Internet with a unique user-friendly name. DNS organizes the name space in a hierarchical structure to decentralize the responsibilities involved in naming. DNS can be pictured as an inverted hierarchical tree structure with one root node at the top and […]
TELNET is a client/server application that allows a user to log on to a remote machine, giving the user access to the remote system. TELNET uses the network virtual terminal (NVT) system to encode characters on the local system. On the server machine, NVT decodes the characters to a form acceptable to the remote machine. […]
Lets See some Basic WWW HTTP study notes The World Wide Web (WWW) is a repository of information linked together from points all over the world. Hypertexts are documents linked to one another through the concept of pointers. Browsers interpret and display a Web document. A browser consists of a controller, client programs, and interpreters. […]
The five areas comprising network management are configuration management, fault management, performance management, accounting management, and security management. Configuration management is concerned with the physical or logical changes of network entities. It includes the reconfiguration and documentation of hardware, software, and user accounts. Fault management is concerned with the proper operation of each network component. […]
Audio/video files can be downloaded for future use (streaming stored audio/video) or broadcast to clients over the Internet (streaming live audio/video). The Internet can also be used for live audio/video interaction. Audio and video need to be digitized before being sent over the Internet. Audio files are compressed through predictive encoding or perceptual encoding. Joint […]
Cryptography is the science and art of transforming messages to make them secure and immune to attacks. The plaintext is the original message before transformation; the ciphertext is the message after transformation. An encryption algorithm transforms plaintext to ciphertext; a decryption algorithm transforms ciphertext to plaintext. A combination of an encryption algorithm and a decryption […]
Cryptography can provide five services. Four of these are related to the message exchange between Alice and Bob. The fifth is related to the entity trying to access a system for using its resources. Message confidentiality means that the sender and the receiver expect privacy. Message integrity means that the data must arrive at the […]
Topology is the pattern of interconnection of nodes in a local area network(LAN).The topology used helps to select the communication medium and the other network devices.While choosing a topology,care has to be taken that the installation cost is minimum,the network so designed should be reliable and flexible. Network topologies are categorized into the following basic […]
A protocol is the special set of rules that two or more machines on a network follow to communicate with each other. They are the standards that allow computers to communicate. A protocol defines how computers identify one another on a network, the form that the data should take in transit, and how this information is processed once it […]