In the Linux/Unix system to check storage details, we use the df command.df (disk free) command the df command is used to report file system disk space usage using the terminal in the Linux system. It displays total space, used space, and available space.SyntaxThe general syntax of the df command is as follow:$ df [OPTION]... [FILE]...Brief description of options available in the df command.Sr.No.Option & Description1-a, --allInclude duplicate, pseudo, inaccessible file systems2-B, --block-size=SIZEScale sizes before printing3-h, --human-readableDisplay sizes in powers of 10244-H, --siDisplay sizes in powers of 10005-l, --localLimit listing to local file systems6--no-syncDon’t synchronize before getting usage info7--syncSynchronize before getting ... Read More

To change the shell working directory, we use the cd command in the Linux system.cd (change directory) The cd command used to change the current working directory in the Linux/Unix operating system. In the Windows operating system for the same purpose the cd or chdir command available. The cd command also available in the EFI shell (Extensible Firmware Shell). By default, the current shell working directory is home directory.SyntaxThe general syntax of the cd command is as follows −cd [-L| [-P [-e]] [-@]] [directory]A brief description of options available in the cd command.Sr.No.Option & Description1-LForce soft links to as followedResolve symbolic ... Read More

To change the file owner and group, we use the chown command in the Linux operating system.We know that Linux is a multiuser operating system so every file or directory belongs to an owner and group.To change ownership of files or directories we use chown command in the Linux system. This command is also available in the IBM i operating system. The chgrp command is also used to change only the group ownership of the file in the Linux system.SyntaxThe general syntax of the chown command is as followschown [OPTION]... [OWNER] [: [GROUP]] FILE... chown [OPTION]... --reference=RFILE FILE...A brief description ... Read More

We know that the Linux/Unix is a multiuser operating system files and directories are associated with permission so that only authorized users can access the files.The chmod command is used to change the access permission of files or directories.SyntaxThe general syntax of the chmod command is as follows −chmod [OPTION]... [Mode]... [File]...Syntax of chmod command is as followed, it contains some three parameters that will help to set or change the permission of the file.We will discuss each parameter in detail so that you can have a better idea of using the chmod command.A brief description of options available in ... Read More

ATM is a connection-oriented network at a point where the sender or user which access devices are known as end-point, these end-points connected through a user to network interface (UNI) to the switches on the network, these switches provide a network to network interface (NNI).The architecture of the ATM is shown in the figure below.ATM transfers the information through a transmission path which is made up of a logical virtual path and virtual channel. The transmission path consists of the physical cable, which is connected to an ATM switch. The cables have a transfer speed of up to 155 megabits ... Read More

ATM stands for Asynchronous transfer mode. It is a switching technique used by telecommunication networks that uses asynchronous time-division multiplexing to encode data into small, fixed-sized cells. ATMs can be used for efficient data transfer over highspeed data networks. ATM provides real-time and non-real-time services.ServicesThe services provided by ATM are as follows−Available Bit Rate: It provides a guaranteed minimum capacity, but data can be burst to higher capacities when network traffic is lower.Constant Bit Rate: It is used to specify a fixed bit rate so that data is sent in a steady stream. This is analogous to a leased line.Unspecified ... Read More

An ultimate form of multiplexing used in parts of the cellular telephone system and for some satellite communication is called Code Division Multiplexing (CDM). The specific version of CDM used in cell phones is called Code Division Multi-Access (CDMA).CDM does not rely on physical properties, including frequency or time. It can depend on an interesting numerical idea such as values from orthogonal vector spaces can be merged and separated without interference. The specific form used in the telephone network is the easiest to learn. Each sender is created a unique binary code Ci that is called chip sequence.Chip sequences are ... Read More

A transmission system is classified as asynchronous if the system enables the physical channel to be useless for an arbitrary time between two transmissions. The asynchronous design of communication is well-appropriated to applications that create data at random (e.g., a user classifying on a keyboard or a user that press on a link to include a web page, reads for a while, and then press on a link to include another page).The drawback of asynchrony improves from the lack of coordination between sender and receiver while the channel is empty. A receiver cannot know how long the channel will remain ... Read More

The alternative to parallel transmission, called serial transmission, sends one bit at a time. With the importance of speed, it may seem that anyone designing a data communications system would choose parallel transmission. However, most communication systems use serial mode.Following are the two main reasons for serial transmission−First, serial networks can be continued over long distances at much less cost because fewer physical wires are required, and intermediate electronic elements are less cheap.Second, using only one physical wire defines that there are never timing issues caused by one wire being slightly higher than another (a difference of millimetres can be ... Read More

To establish a reliable service between two machines on a network, transport protocols are implemented, which somehow resembles the data link protocols implemented at layer 2. The major difference lies in the fact that the data link layer uses a physical channel between two routers while the transport layer uses a subnet.Following are the issues for implementing transport protocols−Types of ServiceThe transport layer also determines the type of service provided to the users from the session layer. An error-free point-to-point communication to deliver messages in the order in which they were transmitted is one of the key functions of the ... Read More