Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Economics & Finance
High-Level Data Link Control (HDLC) is a bit-oriented protocol developed by the International Organization for Standardization (ISO) under standards ISO 3309 and ISO 4335. It defines a packetization standard for serial connections and has been widely adopted worldwide due to its versatility in supporting both half-duplex and full-duplex communication, point-to-point and multi-point networks, and switched or unswitched media. HDLC provides different modes of operation, including a sliding window mode for reliable delivery and an unnumbered data mode for unreliable delivery used by some Internet applications where higher-level protocols like TCP handle retransmission. HDLC Station ... Read More
The full form of ISCII is Indian Script Code for Information Interchange. It was established by the Bureau of Indian Standards in 1991 and is based on the earlier Indian Standard IS 10401:1982. ISCII is a coding scheme specifically designed for representing Indian languages in digital format. ISCII is an 8-bit encoding standard where the lower 128 characters (0-127) conform to the ASCII standard, and the higher 128 characters (128-255) are used to encode characters from Indian scripts. This design ensures backward compatibility with ASCII while providing support for Indic languages. ISCII 8-bit Character ... Read More
Many users are unaware that sending emails can disclose more information than intended, particularly through email headers that may contain sensitive data like your IP address. This information can reveal your approximate location and other private details to recipients. When you compose and send an email, additional metadata called header information is automatically attached. Depending on your email provider and the method used to send emails, this header may include your IP address, which recipients can use to determine your general location and other personal information. Email Header Information Flow ... Read More
The Bifid Cipher is a polygraphic substitution cipher invented by French amateur cryptographer Felix Delastelle in the late 19th century. Unlike monoalphabetic ciphers such as the Caesar Cipher, it encrypts pairs of letters at a time, making it significantly more secure. The cipher is based on a Polybius square, a 5×5 grid containing the alphabet (usually combining I and J into one cell). The grid is typically filled using a keyword first, followed by the remaining letters of the alphabet in order. Polybius Square with Keyword "CRYPTO" ... Read More
The rapid evolution of the internet has brought forth the pressing need for a new generation of network infrastructure, with Internet Protocol version 6 (IPv6) at the forefront. As we approach exhaustion of available IPv4 addresses, IPv6 adoption is not only necessary but transformative for digital connectivity worldwide. IPv6 is reshaping our understanding of internet communication and has undeniable impact on emerging technologies like the Internet of Things (IoT). This protocol provides the foundation for connecting billions of devices in our increasingly digital world. Understanding IPv4 vs IPv6 IPv4 and IPv6 differ primarily in address space capacity, ... Read More
Let us understand the key differences between Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA), two fundamental multiple access techniques used in wireless communication systems. TDMA (Time Division Multiple Access) TDMA represents Time Division Multiple Access. It is a cellular mobile technology that depends on time-division multiplexing (TDM) techniques. In TDMA, each user is allocated the entire bandwidth of the medium for a specific time slot. After this time expires, control is transferred to the next user in a round-robin fashion. A simple example is television broadcasting where a 10-minute program is followed by ... Read More
HDLC (High-Level Data Link Control) is a bit-oriented synchronous data link layer protocol that provides error-free transmission of data between network points. It supports both connection-oriented and connectionless services, organizing data into structured units called frames for reliable transmission across networks. HDLC frames are transmitted over synchronous or asynchronous links using frame delimiters called flags, which contain specific bit sequences that mark the beginning and end of each frame without appearing within the frame content itself. Types of HDLC Frames HDLC defines three distinct types of frames, each serving different communication purposes: Information Frames (I-Frames) ... Read More
NetMeeting was Microsoft's pioneering video conferencing solution that came pre-installed with Windows 95 and Windows XP. This application provided basic video calling, desktop sharing, and collaborative features before being replaced by Windows Meeting Space in Windows Vista. While no longer supported, understanding NetMeeting helps appreciate the evolution of modern video conferencing tools. NetMeeting offered a simple, menu-driven interface that made it accessible to users with basic technical knowledge. It supported both audio and video communication over network connections, making it an early solution for remote collaboration. How NetMeeting Worked NetMeeting used a directory server model where users ... Read More
POP3 and IMAP are the most widely used standard protocols for email retrieval. Both protocols are supported by almost all current email clients and servers. Understanding their differences is crucial for choosing the right email setup for your needs. What is POP3? Post Office Protocol Version 3 (POP3) is an application layer protocol used by email clients to retrieve email messages from mail servers over TCP/IP networks. POP3 operates on a simple principle: download messages from the server to the local device, typically removing them from the server afterward. POP3 uses port 110 for standard connections and ... Read More
Binary Synchronous Communication (BISYNC) is a character-oriented communication protocol developed by IBM that uses synchronous transmission to transfer data between devices. In BISYNC, data is transmitted in structured blocks called frames, which include control characters for synchronization and error detection. BISYNC was designed to provide reliable data communication by using a complex set of control characters to manage data flow and maintain synchronization between sender and receiver. The protocol uses either EBCDIC or ASCII encoding for character representation and was commonly used with 3270 terminals for mainframe communication. BISYNC Frame Structure ... Read More