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VPN and VNC are two distinct technologies with different purposes. Both involve network connectivity, but they serve different functions and operate at separate layers of the networking stack. VNC is a graphical desktop-sharing system that allows network-based remote control and access to a computer's desktop environment. VPNs focus on establishing secure and private network connections over public networks while providing encryption and anonymity. What is VPN? A Virtual Private Network (VPN) is a technology that creates a secure and encrypted connection over a public network, such as the internet. It allows users to connect to a private ... Read More
Local Area Networks are of two types − Peer to Peer network and client/server network. A client/server network is a network architecture where certain computers act as servers that provide resources and services, while other computers act as clients that request and use these services. This centralized approach forms the foundation of most modern business networks. How Client/Server Networks Work In this architecture, a server is a dedicated computer that provides network resources and services to other computers when requested. A client is a computer running programs that request services from servers. All network resources such as ... Read More
Fletcher's checksum is an error-detection technique that uses two checksums to determine single-bit errors in a message transmitted over network channels. It is a block code technique that was devised by John G. Fletcher in the 1970s at Lawrence Livermore Labs, USA. The checksums are created based on the data values in the data blocks to be transmitted and appended to the data. When the receiver gets this data, the checksums are re-calculated and compared with the existing checksums. A non-match indicates an error. The error-detection capabilities of this method are nearly the same as that of Cyclic ... Read More
High-Level Data Link Control (HDLC) is a bit-oriented data link layer protocol standardized by the International Organization for Standardization (ISO). It enables reliable, high-speed communication by providing error detection, flow control, and frame sequencing for data transmission between network devices. HDLC was developed based on IBM's Synchronous Data Link Control (SDLC) protocol. Unlike character-oriented protocols, HDLC can transmit bit strings of variable length, making it more flexible and efficient. The basic unit of data communication in HDLC is called a frame. HDLC Frame Types HDLC defines three types of frames to support different communication modes and configurations: ... Read More
As network administrators or anyone working with network troubleshooting, you will often encounter the commands ifconfig and ip. Both these commands are used in Unix-based operating systems for network interface configuration, but they have significant differences in capabilities, syntax, and maintenance status. Introduction to Ifconfig Ifconfig (Interface Configuration) is a system administration utility in Unix and Unix-like operating systems to configure, control, and query TCP/IP network interface parameters. It is part of the net-tools package which has been present since the early days of Linux. Let's examine a basic ifconfig command: $ ifconfig ... Read More
HDLC (High-Level Data Link Control) and PPP (Point-to-Point Protocol) are two widely used data link layer protocols for communication between network devices. While both protocols facilitate data exchange between connected devices, they differ significantly in their design, features, and applications. What is HDLC? High-Level Data Link Control (HDLC) is a synchronous, bit-oriented data link layer protocol used for transmitting data over point-to-point and multipoint links. It provides reliable and efficient data transmission between network devices. HDLC operates in two primary modes: Normal Response Mode (NRM) − One device (primary station) controls communication by initiating and ... Read More
A Wireless Sensor Network (WSN) is a distributed network of small, autonomous devices called sensor nodes that can sense, process, and communicate data wirelessly. These networks combine distributed communication, computing, and sensing capabilities to monitor physical or environmental conditions such as temperature, humidity, pressure, or motion. WSNs are characterized as infrastructure-less, fault-tolerant, and self-organizing networks that provide opportunities for low-cost, easy-to-apply, rapid, and flexible installations in various environments for diverse applications. Wireless Sensor Network Architecture Base Station Data Sink ... Read More
A polynomial code is a linear code where valid codewords are represented as polynomials that are divisible by a shorter fixed polynomial called the generator polynomial. These codes are fundamental in digital communication systems for error detection and correction during data transmission and storage. The key principle behind polynomial codes is that data bits are treated as coefficients of polynomials, enabling mathematical operations that can detect and correct transmission errors effectively. Types of Polynomial Codes The main types of polynomial codes include: Cyclic Redundancy Code (CRC) − Most commonly used for error detection in networking ... Read More
A mode in HDLC defines the relationship between two machines in a network and describes who controls the link. HDLC determines three types of stations: primary, secondary, and combined. A primary station is the controlling station on a connection. It controls the secondary stations and handles data flow and error recovery. A secondary station exists on a connection where there is a primary station. The secondary station is controlled by the primary station and has no explicit authority for maintaining the connection. A combined station combines the functions of both primary and secondary stations, operating as an ... Read More
Voice over LTE (VoLTE) is a standard for delivering voice communication and data services over 4G LTE networks using an all-IP architecture. Unlike traditional voice calls that use circuit-switched networks, VoLTE transmits voice as data packets over the LTE data network. VoLTE leverages the IP Multimedia Subsystem (IMS) to provide high-quality voice, video, and messaging services. This technology enables faster call setup times, better voice quality, and the ability to use voice and data services simultaneously. How VoLTE Works VoLTE operates entirely on packet-switched technology, converting all voice communications into IP packets. When a user makes a ... Read More