A general purpose computer has four main sections: the arithmetic and logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by buses, often made of groups of wires.
The control unit, ALU, registers, and basic I/O (and often other hardware closely linked with these) are collectively known as a central processing unit (CPU). Early CPUs were composed of many separate components but since the mid-1970s CPUs have typically been constructed on a single integrated circuit called a microprocessor.
Saturday, October 11, 2008
laptop computer
A laptop computer or simply laptop (also notebook computer, notebook and notepad) is a small mobile computer, typically weighing 3 to 12 pounds (1.4 to 5.4 kg), although older laptops may weigh more.
Laptops usually run on a single main battery or from an external AC/DC adapter that charges the battery while also supplying power to the computer itself even in the event of a power failure. This very powerful main battery should not be confused with the much smaller battery nearly all computers use to run the real-time clock and backup BIOS configuration into the CMOS memory when the computer is without power.
Laptops contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturized and optimized for mobile use and efficient power consumption, although typically less powerful for the same price. Laptops usually have liquid crystal displays and most of them use different memory modules for their random access memory (RAM), for instance, SO-DIMM in lieu of the larger DIMMs. In addition to a built-in keyboard, they may utilize a touchpad (also known as a trackpad) or a pointing stick for input, though an external keyboard or mouse can usually be attached
Laptops usually run on a single main battery or from an external AC/DC adapter that charges the battery while also supplying power to the computer itself even in the event of a power failure. This very powerful main battery should not be confused with the much smaller battery nearly all computers use to run the real-time clock and backup BIOS configuration into the CMOS memory when the computer is without power.
Laptops contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturized and optimized for mobile use and efficient power consumption, although typically less powerful for the same price. Laptops usually have liquid crystal displays and most of them use different memory modules for their random access memory (RAM), for instance, SO-DIMM in lieu of the larger DIMMs. In addition to a built-in keyboard, they may utilize a touchpad (also known as a trackpad) or a pointing stick for input, though an external keyboard or mouse can usually be attached
Computer hardware
Computer hardware is the physical part of a computer, including its digital circuitry, as distinguished from the computer software that executes within the hardware. The hardware of a computer is infrequently changed, in comparison with software and hardware data, which are "soft" in the sense that they are readily created, modified or erased on the computer. Firmware is a special type of software that rarely, if ever, needs to be changed and so is stored on hardware devices such as read-only memory (ROM) where it is not readily changed (and is, therefore, "firm" rather than just "soft").
Most computer hardware is not seen by normal users. It is in embedded systems in automobiles, microwave ovens, electrocardiograph machines, compact disc players, and other devices. Personal computers, the computer hardware familiar to most people, form only a small minority of computers (about 0.2% of all new computers produced in 2003). See Market statistics.
* Motherboard
* Power supply
* Storage controllers
* Video display controller
* Removable media devices
* Internal storage
* Sound card
* Networking
* Other peripherals
* Input
* Output
Most computer hardware is not seen by normal users. It is in embedded systems in automobiles, microwave ovens, electrocardiograph machines, compact disc players, and other devices. Personal computers, the computer hardware familiar to most people, form only a small minority of computers (about 0.2% of all new computers produced in 2003). See Market statistics.
* Motherboard
* Power supply
* Storage controllers
* Video display controller
* Removable media devices
* Internal storage
* Sound card
* Networking
* Other peripherals
* Input
* Output
Types of networks
Personal Area Network (PAN)
A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that are used in a PAN are printers, fax machines, telephones, PDAs or scanners. The reach of a PAN is typically within about 20-30 feet (approximately 6-9 metres).
Personal area networks may be wired with computer buses such as USB and FireWire. A wireless personal area network (WPAN) can also be made possible with network technologies such as IrDA and Bluetooth..
Local Area Network (LAN)
A network covering a small geographic area, like a home, office, or building. Current LANs are most likely to be based on Ethernet technology. For example, a library may have a wired or wireless LAN for users to interconnect local devices (e.g., printers and servers) and to connect to the internet. On a wired LAN, PCs in the library are typically connected by category 5 (Cat5) cable, running the IEEE 802.3 protocol through a system of interconnection devices and eventually connect to the internet. The cables to the servers are typically on Cat 5e enhanced cable, which will support IEEE 802.3 at 1 Gbit/s. A wireless LAN may exist using a different IEEE protocol, 802.11b or 802.11g. The staff computers (bright green in the figure) can get to the color printer, checkout records, and the academic network and the Internet. All user computers can get to the Internet and the card catalog. Each workgroup can get to its local printer. Note that the printers are not accessible from outside their workgroup.
Typical library network, in a branching tree topology and controlled access to resources
All interconnected devices must understand the network layer (layer 3), because they are handling multiple subnets (the different colors). Those inside the library, which have only 10/100 Mbit/s Ethernet connections to the user device and a Gigabit Ethernet connection to the central router, could be called "layer 3 switches" because they only have Ethernet interfaces and must understand IP. It would be more correct to call them access routers, where the router at the top is a distribution router that connects to the Internet and academic networks' customer access routers.
The defining characteristics of LANs, in contrast to WANs (wide area networks), include their higher data transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines. Current Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to 10 Gbit/s. This is the data transfer rate. IEEE has projects investigating the standardization of 100 Gbit/s, and possibly 40 Gbit/s.
A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that are used in a PAN are printers, fax machines, telephones, PDAs or scanners. The reach of a PAN is typically within about 20-30 feet (approximately 6-9 metres).
Personal area networks may be wired with computer buses such as USB and FireWire. A wireless personal area network (WPAN) can also be made possible with network technologies such as IrDA and Bluetooth..
Local Area Network (LAN)
A network covering a small geographic area, like a home, office, or building. Current LANs are most likely to be based on Ethernet technology. For example, a library may have a wired or wireless LAN for users to interconnect local devices (e.g., printers and servers) and to connect to the internet. On a wired LAN, PCs in the library are typically connected by category 5 (Cat5) cable, running the IEEE 802.3 protocol through a system of interconnection devices and eventually connect to the internet. The cables to the servers are typically on Cat 5e enhanced cable, which will support IEEE 802.3 at 1 Gbit/s. A wireless LAN may exist using a different IEEE protocol, 802.11b or 802.11g. The staff computers (bright green in the figure) can get to the color printer, checkout records, and the academic network and the Internet. All user computers can get to the Internet and the card catalog. Each workgroup can get to its local printer. Note that the printers are not accessible from outside their workgroup.
Typical library network, in a branching tree topology and controlled access to resources
All interconnected devices must understand the network layer (layer 3), because they are handling multiple subnets (the different colors). Those inside the library, which have only 10/100 Mbit/s Ethernet connections to the user device and a Gigabit Ethernet connection to the central router, could be called "layer 3 switches" because they only have Ethernet interfaces and must understand IP. It would be more correct to call them access routers, where the router at the top is a distribution router that connects to the Internet and academic networks' customer access routers.
The defining characteristics of LANs, in contrast to WANs (wide area networks), include their higher data transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines. Current Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to 10 Gbit/s. This is the data transfer rate. IEEE has projects investigating the standardization of 100 Gbit/s, and possibly 40 Gbit/s.
Types of networks
Campus Area Network (CAN)
A network that connects two or more LANs but that is limited to a specific and contiguous geographical area such as a college campus, industrial complex, or a military base. A CAN may be considered a type of MAN (metropolitan area network), but is generally limited to an area that is smaller than a typical MAN. This term is most often used to discuss the implementation of networks for a contiguous area. This should not be confused with a Controller Area Network. A LAN connects network devices over a relatively short distance. A networked office building, school, or home usually contains a single LAN, though sometimes one building will contain a few small LANs (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet.
Metropolitan Area Network (MAN)
A Metropolitan Area Network is a network that connects two or more Local Area Networks or Campus Area Networks together but does not extend beyond the boundaries of the immediate town/city. Routers, switches and hubs are connected to create a Metropolitan Area Network.
Wide Area Network (WAN)
A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.
Global Area Network (GAN)
Global area networks (GAN) specifications are in development by several groups, and there is no common definition. In general, however, a GAN is a model for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc. The key challenge in mobile communications is "handing off" the user communications from one local coverage area to the next. In IEEE Project 802, this involves a succession of terrestrial Wireless local area networks (WLAN).
A network that connects two or more LANs but that is limited to a specific and contiguous geographical area such as a college campus, industrial complex, or a military base. A CAN may be considered a type of MAN (metropolitan area network), but is generally limited to an area that is smaller than a typical MAN. This term is most often used to discuss the implementation of networks for a contiguous area. This should not be confused with a Controller Area Network. A LAN connects network devices over a relatively short distance. A networked office building, school, or home usually contains a single LAN, though sometimes one building will contain a few small LANs (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet.
Metropolitan Area Network (MAN)
A Metropolitan Area Network is a network that connects two or more Local Area Networks or Campus Area Networks together but does not extend beyond the boundaries of the immediate town/city. Routers, switches and hubs are connected to create a Metropolitan Area Network.
Wide Area Network (WAN)
A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.
Global Area Network (GAN)
Global area networks (GAN) specifications are in development by several groups, and there is no common definition. In general, however, a GAN is a model for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc. The key challenge in mobile communications is "handing off" the user communications from one local coverage area to the next. In IEEE Project 802, this involves a succession of terrestrial Wireless local area networks (WLAN).
Network Classification
Network Classification
The following list presents major categories used for classifying networks.
Scale
Based on the scale networks can be classified as Local Area Network (LAN), Wide Area Network (WAN) , Metropolitan Area Network (MAN) etc.,
Connection method
Computer networks can also be classified according to the hardware technology that is used to connect the individual devices in the network such as Optical fibre, Ethernet, Wireless LAN, HomePNA, or Power line communication.
Ethernet uses physical wiring to connect devices. Often deployed devices are hubs, switches, bridges, and/or routers.
Wireless LAN technology is designed to connect devices without wiring. These devices use radio waves as transmission medium.
Functional relationship (Network Architectures)
Computer networks may be classified according to the functional relationships which exist among the elements of the network, e.g., Active Networking, Client-server and Peer-to-peer (workgroup) architecture.
Network topology
Computer networks may be classified according to the network topology upon which the network is based, such as Bus network, Star network, Ring network, Mesh network, Star-bus network, Tree or Hierarchical topology network, etc.
Network Topology signifies the way in which devices in the network see their logical relations to one another. The use of the term "logical" here is significant. That is, network topology is independent of the "physical" layout of the network. Even if networked computers are physically placed in a linear arrangement, if they are connected via a hub, the network has a Star topology, rather than a Bus Topology. In this regard the visual and operational characteristics of a network are distinct; the logical network topology is not necessarily the same as the physical layout.
The following list presents major categories used for classifying networks.
Scale
Based on the scale networks can be classified as Local Area Network (LAN), Wide Area Network (WAN) , Metropolitan Area Network (MAN) etc.,
Connection method
Computer networks can also be classified according to the hardware technology that is used to connect the individual devices in the network such as Optical fibre, Ethernet, Wireless LAN, HomePNA, or Power line communication.
Ethernet uses physical wiring to connect devices. Often deployed devices are hubs, switches, bridges, and/or routers.
Wireless LAN technology is designed to connect devices without wiring. These devices use radio waves as transmission medium.
Functional relationship (Network Architectures)
Computer networks may be classified according to the functional relationships which exist among the elements of the network, e.g., Active Networking, Client-server and Peer-to-peer (workgroup) architecture.
Network topology
Computer networks may be classified according to the network topology upon which the network is based, such as Bus network, Star network, Ring network, Mesh network, Star-bus network, Tree or Hierarchical topology network, etc.
Network Topology signifies the way in which devices in the network see their logical relations to one another. The use of the term "logical" here is significant. That is, network topology is independent of the "physical" layout of the network. Even if networked computers are physically placed in a linear arrangement, if they are connected via a hub, the network has a Star topology, rather than a Bus Topology. In this regard the visual and operational characteristics of a network are distinct; the logical network topology is not necessarily the same as the physical layout.
Computer networking
Computer networking is the engineering discipline concerned with communication between computer systems or devices. Networking, routers, routing protocols, and networking over the public Internet have their specifications defined in documents called RFCs.Computer networking is sometimes considered a sub-discipline of telecommunications, computer science, information technology and/or computer engineering. Computer networks rely heavily upon the theoretical and practical application of these scientific and engineering disciplines. A computer network is any set of computers or devices connected to each other with the ability to exchange data. Examples of networks are:
local area network (LAN), which is usually a small network constrained to a small geographic area.
wide area network (WAN) that is usually a larger network that covers a large geographic area.
wireless LANs and WANs (WLAN & WWAN) is the wireless equivalent of the LAN and WAN All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, coaxial cable, optical fiber, and various wireless technologies. The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the
local area network (LAN), which is usually a small network constrained to a small geographic area.
wide area network (WAN) that is usually a larger network that covers a large geographic area.
wireless LANs and WANs (WLAN & WWAN) is the wireless equivalent of the LAN and WAN All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, coaxial cable, optical fiber, and various wireless technologies. The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the
Clients
Clients
Remember, all computers on the Internet (a wide area network, or WAN) can be lumped into two groups: servers and clients, which communicate with one another.
Independent computers connected to a server are called clients. Most likely, your home or office computer does not provide services to other computers. Therefore, it is a client.
Clients run multiple client software applications that perform specific functions.
For example,
An email application such as Microsoft Outlook is client software.
Your web browser (such as Internet Explorer or Netscape) is client software.
Remember, all computers on the Internet (a wide area network, or WAN) can be lumped into two groups: servers and clients, which communicate with one another.
Independent computers connected to a server are called clients. Most likely, your home or office computer does not provide services to other computers. Therefore, it is a client.
Clients run multiple client software applications that perform specific functions.
For example,
An email application such as Microsoft Outlook is client software.
Your web browser (such as Internet Explorer or Netscape) is client software.
server
server
All computers on the Internet (a wide area network, or WAN) can be lumped into two groups: servers and clients. In a network, clients and servers communicate with one another.
A server is the common source that :
Provides shared services (for example, network security measures) with other machines
AND
Manages resources (for example, one printer many people use) in a network.
The term server is often used to describe the hardware (computer), but the term also refers to the software (application) running on the computer. Many servers are dedicated, meaning they only perform specific tasks.
For example,
An email server is a computer that has software running on it allowing it to "serve" email-related services.
A web server has software running on it that allows it to "serve" web-related services.
All computers on the Internet (a wide area network, or WAN) can be lumped into two groups: servers and clients. In a network, clients and servers communicate with one another.
A server is the common source that :
Provides shared services (for example, network security measures) with other machines
AND
Manages resources (for example, one printer many people use) in a network.
The term server is often used to describe the hardware (computer), but the term also refers to the software (application) running on the computer. Many servers are dedicated, meaning they only perform specific tasks.
For example,
An email server is a computer that has software running on it allowing it to "serve" email-related services.
A web server has software running on it that allows it to "serve" web-related services.
Servers and clients communicate
Servers and clients communicate
Your computer (client hardware) is running a web browser such as Internet Explorer (client software).
When you want to surf the web, your browser connects to a remote server and requests a web page.
The remote server (server hardware) runs web server software (server software).
The web server sends the web page to your computer's web browser.
Your web browser displays the page.
Your computer (client hardware) is running a web browser such as Internet Explorer (client software).
When you want to surf the web, your browser connects to a remote server and requests a web page.
The remote server (server hardware) runs web server software (server software).
The web server sends the web page to your computer's web browser.
Your web browser displays the page.
microprocessor
A microprocessor incorporates most or all of the functions of a central processing unit (CPU) on a single integrated circuit (IC). The first microprocessors emerged in the early 1970s and were used for electronic calculators, using BCD arithmetic on 4-bit words. Other embedded uses of 4 and 8-bit microprocessors, such as terminals, printers, various kinds of automation etc, followed rather quickly. Affordable 8-bit microprocessors with 16-bit addressing also led to the first general purpose microcomputers in the mid-1970s.
Computer processors were for a long period constructed out of small and medium-scale ICs containing the equivalent of a few to a few hundred transistors. The integration of the whole CPU onto a single VLSI chip therefore greatly reduced the cost of processing capacity. From their humble beginnings, continued increases in microprocessor capacity have rendered other forms of computers almost completely obsolete (see history of computing hardware), with one or more microprocessor as processing element in everything from the smallest embedded systems and handheld devices to the largest mainframes and supercomputers.
Since the early 1970s, the increase in capacity of microprocessors has been known to generally follow Moore's Law, which suggests that the complexity of an integrated circuit, with respect to minimum component cost, doubles every 18 months. In the late 1990s, heat generation (TDP), due to current leakage and other factors, emerged as a leading developmental constraint.
Computer processors were for a long period constructed out of small and medium-scale ICs containing the equivalent of a few to a few hundred transistors. The integration of the whole CPU onto a single VLSI chip therefore greatly reduced the cost of processing capacity. From their humble beginnings, continued increases in microprocessor capacity have rendered other forms of computers almost completely obsolete (see history of computing hardware), with one or more microprocessor as processing element in everything from the smallest embedded systems and handheld devices to the largest mainframes and supercomputers.
Since the early 1970s, the increase in capacity of microprocessors has been known to generally follow Moore's Law, which suggests that the complexity of an integrated circuit, with respect to minimum component cost, doubles every 18 months. In the late 1990s, heat generation (TDP), due to current leakage and other factors, emerged as a leading developmental constraint.
motherboard
A motherboard is the central or primary printed circuit board (PCB) making up a complex electronic system, such as a modern computer or laptop. It is also known as a mainboard, baseboard, system board, planar board, or, on Apple computers, a logic board, and is sometimes abbreviated casually as mobo.
Most motherboards produced today are designed for so-called IBM-compatible computers, which held over 96% of the global personal computer market in 2005.Motherboards for IBM-compatible computers are specifically covered in the PC motherboard article.
A motherboard, like a backplane, provides the electrical connections by which the other components of the system communicate, but unlike a backplane also contains the central processing unit and other subsystems such as real time clock, and some peripheral interfaces.
A typical desktop computer is built with the microprocessor, main memory, and other essential components on the motherboard. Other components such as external storage, controllers for video display and sound, and peripheral devices are typically attached to the motherboard via edge connectors and cables, although in modern computers it is increasingly common to integrate these "peripherals" into the motherboard.
All of the basic circuitry and components required for a computer to function are onboard the motherboard or are connected with a cable. The most important component on a motherboard is the chipset. It often consists of two components or chips known as the Northbridge and Southbridge, though they may also be integrated into a single component. These chips determine, to an extent, the features and capabilities of the motherboard.
Most motherboards produced today are designed for so-called IBM-compatible computers, which held over 96% of the global personal computer market in 2005.Motherboards for IBM-compatible computers are specifically covered in the PC motherboard article.
A motherboard, like a backplane, provides the electrical connections by which the other components of the system communicate, but unlike a backplane also contains the central processing unit and other subsystems such as real time clock, and some peripheral interfaces.
A typical desktop computer is built with the microprocessor, main memory, and other essential components on the motherboard. Other components such as external storage, controllers for video display and sound, and peripheral devices are typically attached to the motherboard via edge connectors and cables, although in modern computers it is increasingly common to integrate these "peripherals" into the motherboard.
All of the basic circuitry and components required for a computer to function are onboard the motherboard or are connected with a cable. The most important component on a motherboard is the chipset. It often consists of two components or chips known as the Northbridge and Southbridge, though they may also be integrated into a single component. These chips determine, to an extent, the features and capabilities of the motherboard.
BIOS
BIOS in part refers to the firmware code run by a PC when first powered on, which is a type of boot loader. The primary function of the BIOS is to identify and initialize system component hardware (such as the video display card, hard disk, and floppy disk) and some other hardware devices. This is to prepare the machine into a known low capability state, so other software programs stored on various media can be loaded, executed, and given control of the PC. This process is known as booting, or booting up, which is short for bootstrapping. Among other classes of computers, the generic terms boot monitor, boot loader or boot ROM were commonly used. Some Sun and Macintosh PowerPC computers used Open Firmware for this purpose. There are a few alternatives for Legacy BIOS in the x86 world: Extensible Firmware Interface, Open Firmware (used on the OLPC XO-1) and coreboot.
The BIOSes of IBM PC class machines can also be said to be a coded program embedded on a chip that recognizes and controls various devices that make up x86 personal computers, and provides a small library of basic Input/Output functions that can be called to operate and control the peripherals such as the keyboard, primitive (800 x 600) display functions and so forth. Computers designed to run Windows ME or Windows 2000, or later, supersede this basic monitor functionality by taking over direct control of the interrupt table and replacing the monitor routines with faster and more robust low-level modules that, unlike the BIOS function set, are re-entrant. Various BIOS functions in ROM were left in control in earlier Windows versions, and the BIOS only comes into play today in the alternate shell CMD.exe, or if the machine is booted into a legacy DOS version.
The term first appeared in the CP/M operating system, describing the part of CP/M loaded during boot time that interfaced directly with the hardware (CP/M machines usually had a simple boot loader in ROM, and nothing else). Most versions of DOS have a file called "IBMBIO.COM" or "IO.SYS" that is analogous to the CP/M disk BIOS.
The BIOSes of IBM PC class machines can also be said to be a coded program embedded on a chip that recognizes and controls various devices that make up x86 personal computers, and provides a small library of basic Input/Output functions that can be called to operate and control the peripherals such as the keyboard, primitive (800 x 600) display functions and so forth. Computers designed to run Windows ME or Windows 2000, or later, supersede this basic monitor functionality by taking over direct control of the interrupt table and replacing the monitor routines with faster and more robust low-level modules that, unlike the BIOS function set, are re-entrant. Various BIOS functions in ROM were left in control in earlier Windows versions, and the BIOS only comes into play today in the alternate shell CMD.exe, or if the machine is booted into a legacy DOS version.
The term first appeared in the CP/M operating system, describing the part of CP/M loaded during boot time that interfaced directly with the hardware (CP/M machines usually had a simple boot loader in ROM, and nothing else). Most versions of DOS have a file called "IBMBIO.COM" or "IO.SYS" that is analogous to the CP/M disk BIOS.
chipset
A chipset is a group of integrated circuits, or chips, that are designed to work together, and are usually marketed as a single product.
Introduction to PC Components
Here you will learn computer hardware tutorials introduction, basic pc components, networking devices, ram, vga, monitor and printer etc. Computer hardware is the physical part of the computer including the digital circuits inside the computer as opposed to the software that carry out the computing instructions. The hardware of a computer is unlikely to change frequently unless due to the crash or for upgrading them. The devices that is capable of storing, executing system instructions and controlling other logical outputs.
Hardware comprises all of the physical part of the computer such as Monitor, CPU, motherboard, ram, CD-Rom, printer, scanner, hard disk, flash drive (AKA pen drive), processor, pci buses, floppy disk, power supply, VGA card, sound card, network interface card, peripherals, joystick, mouse, keyboard, foot pedal, computer fan, camera, headset and others.
On the other hard software is a logical part of a computer and is used to carry out the instructions, storing, executing and developing other software programs. A typical PC consists of a case or chassis in the desktop or tower case and these components.
Motherboard
• CPU
• Computer Fan
• RAM
• BIOS
• Digital Circuitry
• Computer Fan
• PCI Slots
PC Buses
• PCI
• USB
• Hyper-transport
• AGP
• ISA
• EISA
• VLB
Media
• CD-Rom
• DVD-Rom
• Combo box
• Joystick
• BD-Rom drive
Internal storage
• Hard disk (ATA & SATA)
• Data array controller
• Floppy disk
Other Peripheral Devices
• Mouse
• Modems
• Digital Camera
• Sound, Video Cards
• Printer
Output Devices
• Printer
• Scanner
• Monitor
• Speakers
• Headset
• Video output devices
CPU (Central Processing Unit): CPU or central processing unit relates to a specific or processor. The performance of the computer is determined by the CPU chip (processor speed) and the other computer circuitry. Currently, the Pentium chip (processor) is the most popular even though there are other chips available in the market today such as AMD, Motorola and others. The clocks speed becomes most important factor in determining the performance of a computer. The motherboard contains the hardware circuitry and connections that allow the different hardware components of the PC to interact and communicate with each other. Most computer software is being developed for the latest processors so it would be difficult to use the older systems.
Hard Disk Drives – Disk drive is the mechanism to run the disks. All disks need a drive to get the information, read it and put it back to the disks. Hard disk is used to store the data permanently. Often the terms disk and drive used to describe the same thing but it should be clear that a disk is a storage device.
Modem – A modem is used for the modulation and demodulation of the data that is transferred through the modem and the telephone lines. Modem translates the data from digital to analog from analog to digital. Because on the telephone lines data can travel in the form of the analog signals and in the computer data transmits in the form of digital signals. Modems are measured by the speed which is called baud rate. The typical baud rate is 56Kb.
Keyboard – The keyboard is used to type something or input information to the computer. There are different designs and models of the keyboards in the market. The most common layout of the keyboard is QWERTY layout. A standard keyboard has 101 keys and embedded keys.
Video cards-Video cards allow computer to display video, graphics and animation. Some video cards allow computers to display television. A video card with a digital video camera allows users to produce live video. A high speed broadband internet connection is required to watch the videos on net.
Network cards: Network interface cards allow PCs to connect with each other and communicate. Every network computer is required to have a NIC card. NIC cards are required both in wired and wireless networking.
Cables: There are two broad types of cables internal cables, which are embedded on the mother board circuit that performs the communication between the devices and CPU. The other types of the cables are the network cables like coaxial cable, CAT 5, Ethernet cables. These cables are used for the communication purposes between the devices or computers.
Memory – Memory is the one of the important piece of the hardware. Sometimes memory chip memory is confused with the hard disk memory. Sometimes unallocated space of the hard disk is used as virtual memory also known as page file. This type of memory is a temporary memory and is used actual memory is less and requires some additional memory to perform a specific task.
RAM (Random Access Memory) RAM is a memory that is being used by the computer to store the information temporarily. For example when some work is performed on some applications that work is temporarily stored in the RAM. More RAM in the computer more faster computer works. Today at least requirement of a modern PC is 64 RAM. RAM is in the form of a chip and different vendors have developed the RAM of different capacities.
Mouse – Every modern computer requires a mouse for faster operations. Generally a mouse has two buttons left and right to perform different functions. One type of the mouse has a round ball under the bottom. Another type of the mouse use optical system to track the movement of the mouse.
Monitors – The monitor is used to display the information on the screen. All the activities of a computer, functions and tasks are seen on the computer screen and this is called outputting information. Monitors come in many sizes and shapes, monochrome or full colors. Today most computers use LCD screens. It is light weight and consumes less power as compared to the monitors.
Printers – The printer takes the information from the PC and transfers it to the paper of different sizes, which are placed in the printer device. There are three basic types of a printer such as dot matrix, inkjet and laser.
Scanners- Scanners allow you to transfer pictures and photographs to your computer. A scanner is used to scan the images and pictures. You can then send the image to someone, modify it or take a print out of it. With optical character recognition software you can convert printed documents into the text that you can use in the word processor.
Digital camera- You can take the digital photographs with the digital cameras. The images are stored on the memory chip of the digital cameras and you can transfer them to your computer with the USB drive.
Case – Case or casing covers the whole computer’s circuitry. There are two types of casings desktop and tower casing. There is room inside the casing to add or remove components. Cases come in many sizes like desktop, mini, midi and tower. There are some additional empty slots inside the cases such as IDE, USB, ASI, PCI and firewire slots.
Cards – Cards are the hardware components that are added to the computer to increase their functionalities and capabilities.
Sound cards produce the sound like music and voice. The older cars were 8, 16 and then 32 bits.
Color cards allow computers to produce colors. Initially there were 2, 4 and then 16 bits. The main types of the graphic cards are EGA, VGA and SGA. The 32 cards are the standard to display almost billions of the colors on the monitor.
Hardware comprises all of the physical part of the computer such as Monitor, CPU, motherboard, ram, CD-Rom, printer, scanner, hard disk, flash drive (AKA pen drive), processor, pci buses, floppy disk, power supply, VGA card, sound card, network interface card, peripherals, joystick, mouse, keyboard, foot pedal, computer fan, camera, headset and others.
On the other hard software is a logical part of a computer and is used to carry out the instructions, storing, executing and developing other software programs. A typical PC consists of a case or chassis in the desktop or tower case and these components.
Motherboard
• CPU
• Computer Fan
• RAM
• BIOS
• Digital Circuitry
• Computer Fan
• PCI Slots
PC Buses
• PCI
• USB
• Hyper-transport
• AGP
• ISA
• EISA
• VLB
Media
• CD-Rom
• DVD-Rom
• Combo box
• Joystick
• BD-Rom drive
Internal storage
• Hard disk (ATA & SATA)
• Data array controller
• Floppy disk
Other Peripheral Devices
• Mouse
• Modems
• Digital Camera
• Sound, Video Cards
• Printer
Output Devices
• Printer
• Scanner
• Monitor
• Speakers
• Headset
• Video output devices
CPU (Central Processing Unit): CPU or central processing unit relates to a specific or processor. The performance of the computer is determined by the CPU chip (processor speed) and the other computer circuitry. Currently, the Pentium chip (processor) is the most popular even though there are other chips available in the market today such as AMD, Motorola and others. The clocks speed becomes most important factor in determining the performance of a computer. The motherboard contains the hardware circuitry and connections that allow the different hardware components of the PC to interact and communicate with each other. Most computer software is being developed for the latest processors so it would be difficult to use the older systems.
Hard Disk Drives – Disk drive is the mechanism to run the disks. All disks need a drive to get the information, read it and put it back to the disks. Hard disk is used to store the data permanently. Often the terms disk and drive used to describe the same thing but it should be clear that a disk is a storage device.
Modem – A modem is used for the modulation and demodulation of the data that is transferred through the modem and the telephone lines. Modem translates the data from digital to analog from analog to digital. Because on the telephone lines data can travel in the form of the analog signals and in the computer data transmits in the form of digital signals. Modems are measured by the speed which is called baud rate. The typical baud rate is 56Kb.
Keyboard – The keyboard is used to type something or input information to the computer. There are different designs and models of the keyboards in the market. The most common layout of the keyboard is QWERTY layout. A standard keyboard has 101 keys and embedded keys.
Video cards-Video cards allow computer to display video, graphics and animation. Some video cards allow computers to display television. A video card with a digital video camera allows users to produce live video. A high speed broadband internet connection is required to watch the videos on net.
Network cards: Network interface cards allow PCs to connect with each other and communicate. Every network computer is required to have a NIC card. NIC cards are required both in wired and wireless networking.
Cables: There are two broad types of cables internal cables, which are embedded on the mother board circuit that performs the communication between the devices and CPU. The other types of the cables are the network cables like coaxial cable, CAT 5, Ethernet cables. These cables are used for the communication purposes between the devices or computers.
Memory – Memory is the one of the important piece of the hardware. Sometimes memory chip memory is confused with the hard disk memory. Sometimes unallocated space of the hard disk is used as virtual memory also known as page file. This type of memory is a temporary memory and is used actual memory is less and requires some additional memory to perform a specific task.
RAM (Random Access Memory) RAM is a memory that is being used by the computer to store the information temporarily. For example when some work is performed on some applications that work is temporarily stored in the RAM. More RAM in the computer more faster computer works. Today at least requirement of a modern PC is 64 RAM. RAM is in the form of a chip and different vendors have developed the RAM of different capacities.
Mouse – Every modern computer requires a mouse for faster operations. Generally a mouse has two buttons left and right to perform different functions. One type of the mouse has a round ball under the bottom. Another type of the mouse use optical system to track the movement of the mouse.
Monitors – The monitor is used to display the information on the screen. All the activities of a computer, functions and tasks are seen on the computer screen and this is called outputting information. Monitors come in many sizes and shapes, monochrome or full colors. Today most computers use LCD screens. It is light weight and consumes less power as compared to the monitors.
Printers – The printer takes the information from the PC and transfers it to the paper of different sizes, which are placed in the printer device. There are three basic types of a printer such as dot matrix, inkjet and laser.
Scanners- Scanners allow you to transfer pictures and photographs to your computer. A scanner is used to scan the images and pictures. You can then send the image to someone, modify it or take a print out of it. With optical character recognition software you can convert printed documents into the text that you can use in the word processor.
Digital camera- You can take the digital photographs with the digital cameras. The images are stored on the memory chip of the digital cameras and you can transfer them to your computer with the USB drive.
Case – Case or casing covers the whole computer’s circuitry. There are two types of casings desktop and tower casing. There is room inside the casing to add or remove components. Cases come in many sizes like desktop, mini, midi and tower. There are some additional empty slots inside the cases such as IDE, USB, ASI, PCI and firewire slots.
Cards – Cards are the hardware components that are added to the computer to increase their functionalities and capabilities.
Sound cards produce the sound like music and voice. The older cars were 8, 16 and then 32 bits.
Color cards allow computers to produce colors. Initially there were 2, 4 and then 16 bits. The main types of the graphic cards are EGA, VGA and SGA. The 32 cards are the standard to display almost billions of the colors on the monitor.
How to Configure a Network
In this section you will learn how to configure a network, peer to peer, client server, workstation, server, basic data communication.
Peer to Peer network model
Before configuring a computer network, you have to decide that, which networking model you require. There are two main types of network models. Peer to peer and client-server network model. In the peer to peer network model you simply use the same Workgroup for all the computers and a unique name for each computer.
Additionally, you will have to give a unique IP address of the same class A, B, or C for all the computers in your network and its related subnet mask e.g if you decide to use class A IP address for your three computers in your Peer to Peer network then your IP address/Subnet mask settings can be as follows.
Computer Name IP Address Subnet Mask Workgroup
PC1 100.100.100.1 255.0.0.0 Officenetwork
PC2 100.100.100.2 255.0.0.0 Officenetwork
PC3 100.100.100.3 255.0.0.0 Officenetwor
Please note that the above example is for only illustration purpose so you can choose any IP address, computer name and workgroup name of your interest.
For doing this right click on My Computer and then click Properties then go to the Network Identification section and set these.
In a peer to peer network all computers acts as a client because there is not centralized server. Peer to peer network is used where not security is required in the network.
If a computer fails to work then all other computers work normally in peer to peer network.
Peer to Peer network model
Before configuring a computer network, you have to decide that, which networking model you require. There are two main types of network models. Peer to peer and client-server network model. In the peer to peer network model you simply use the same Workgroup for all the computers and a unique name for each computer.
Additionally, you will have to give a unique IP address of the same class A, B, or C for all the computers in your network and its related subnet mask e.g if you decide to use class A IP address for your three computers in your Peer to Peer network then your IP address/Subnet mask settings can be as follows.
Computer Name IP Address Subnet Mask Workgroup
PC1 100.100.100.1 255.0.0.0 Officenetwork
PC2 100.100.100.2 255.0.0.0 Officenetwork
PC3 100.100.100.3 255.0.0.0 Officenetwor
Please note that the above example is for only illustration purpose so you can choose any IP address, computer name and workgroup name of your interest.
For doing this right click on My Computer and then click Properties then go to the Network Identification section and set these.
In a peer to peer network all computers acts as a client because there is not centralized server. Peer to peer network is used where not security is required in the network.
If a computer fails to work then all other computers work normally in peer to peer network.
Client/Server Network Model
Client/Server Network Model
In the client/server network model a computer plays a centralized role and is known as a server all other computers in the network are known as clients. All client computers access the server simultaneously for files, database, docs, spreadsheets, web pages and resources like hard diver, printer, fax modem, CD/DVD ROM and others. In other words, all the client computes depends on the server and if server fails to respond or crash then networking/communication between the server and the client computes stops.
If you want to configure a client-server network model then first prepare the server. Install Windows 2000 or Windows 2003 Server from the CD on the server computer and make a domain. You can create a domain by this command on the Run “DCPROMO”. You can give this command once you install the server successfully. After you give the DCPROMO command you will be asked for a unique domain name. All the client computers will use the same unique domain name for becoming the part of this domain. This command will install the active directory on the server, DNS and other required things. A step by step wizard will run and will guide you for the rest of the steps. Make sure that a network cable is plugged in the LAN card of the server when you run the DCPROMO.exe command.
When the Active directory is properly installed on the server, restart the server. You can create network users on the server computer and also name/label the network resources like computers/printers etc.
Once you install the server successfully now come to the client computers. Install Windows 2000 professional on your all client computers. Once you install the Windows 2000 professional on the clients the next step is to make this computer (client computer) a part of the network.
Configuration Steps
1. Choose a unique name for each client computer
2. Choose unique IP address for each computer and relevant.
3. Use the same domain name for all client PCs.
Network/System administrators are required to do these administrative tasks on the server and client computers. Any shared resources on the network either on the server or the clients can be access through the My Network Places in the Windows 2000 platform. There is another way to connect to the shared resources by giving this command in the run \\ComputerName\SharedDriveLetter.
Network configurations steps can be implemented by right clicking the My Computer>Properties>
For giving the IP address you will have to right click on the My Network places>properties>Local Area Connection>Properties>Internet Protocols (TCP/IP)>Properties and then give the IP address and subnet mask of the same range and class for all the computers in the network.
In the client/server network model a computer plays a centralized role and is known as a server all other computers in the network are known as clients. All client computers access the server simultaneously for files, database, docs, spreadsheets, web pages and resources like hard diver, printer, fax modem, CD/DVD ROM and others. In other words, all the client computes depends on the server and if server fails to respond or crash then networking/communication between the server and the client computes stops.
If you want to configure a client-server network model then first prepare the server. Install Windows 2000 or Windows 2003 Server from the CD on the server computer and make a domain. You can create a domain by this command on the Run “DCPROMO”. You can give this command once you install the server successfully. After you give the DCPROMO command you will be asked for a unique domain name. All the client computers will use the same unique domain name for becoming the part of this domain. This command will install the active directory on the server, DNS and other required things. A step by step wizard will run and will guide you for the rest of the steps. Make sure that a network cable is plugged in the LAN card of the server when you run the DCPROMO.exe command.
When the Active directory is properly installed on the server, restart the server. You can create network users on the server computer and also name/label the network resources like computers/printers etc.
Once you install the server successfully now come to the client computers. Install Windows 2000 professional on your all client computers. Once you install the Windows 2000 professional on the clients the next step is to make this computer (client computer) a part of the network.
Configuration Steps
1. Choose a unique name for each client computer
2. Choose unique IP address for each computer and relevant.
3. Use the same domain name for all client PCs.
Network/System administrators are required to do these administrative tasks on the server and client computers. Any shared resources on the network either on the server or the clients can be access through the My Network Places in the Windows 2000 platform. There is another way to connect to the shared resources by giving this command in the run \\ComputerName\SharedDriveLetter.
Network configurations steps can be implemented by right clicking the My Computer>Properties>
For giving the IP address you will have to right click on the My Network places>properties>Local Area Connection>Properties>Internet Protocols (TCP/IP)>Properties and then give the IP address and subnet mask of the same range and class for all the computers in the network.
Network Communication Devices
In this tutorial you will learn get the basic introduction to network devices such as nic adapters, routers, hubs, switches, modems, communication cables, lan/wan routers, gateway and other devices. A network is consists of a larger number of the communication devices. The simplest device that is used in the communication is the NIC adapter which is attached with the every computer in a network. If you want to build a LAN, you will need to have computers, hubs, switches, network adapters, UTP/STP cables, routers, internal/external modems, connectors, cable testers and clipping tool.
On the other hand if you need to build WAN, you will need to have routers, switches, dedicated or leased telephone lines such as ISDN lines, frame relay connection and other types of wan communication connections.
There are different communication mediums such as Ethernet cables, copper wire, coaxial cable, fiber optic cables, leased telephone lines and ever air is also a communication medium for the satellite communication. The most common networking medium is the LAN is the Ethernet cable (UTP/STP), which is used in the star topology. Hub is a central device of a network and every computer in a network is directly connected with the hub.
If the hub fails to work, the communication between the computers stops till the hub again starts working. Hub broadcasts the data to its every port, and then finding the destined computer, the data sent toward it. The switch is an advance form of the hub similar in functions but the advanced switches has a switching table in them. A advanced switch stores the MAC address of every attached computer and the data is only sent to the destined computer, unlike the hubs where data is sent to all ports. A router is a key device in the internet communication and wan communication system. A router has software called routing table and the source and destination addresses are stored in the routing table.
A router connects two logically and physically different networks. Router finds the IP address of the next hop (next router) and the data is sent toward it and so on. The well known routers developing companies are Cisco systems, Nortel, DLink and others. Every ISP, banks, corporate offices and multinational companies use routers for LAN and WAN communications and communication in their private networks. A gateway can be device or software in a network.
A gateway device connects the LAN with the internet. A gateway is directly exposed to the internet so it should be securely configured and in and out traffic should be monitored. If you are using DSL connection, you must need a DSL modem in your network. The telephone line is connected with the DSL modem and UTP/STP cable attaches your computer with the DSL modem. Modems are the devices that are used to modulate and demodulate the data. They convert analogue signals to digital and digital signals to analogue so that signals can travel on the telephone lines.
There are certain types of the cables that are used to connect two or more computers in a network. Fiber optic cable acts as a backbone between the ISPs and corporate offices. Data travels at the speed of light on the fiber optic cables. The cost and the installation cost of the fiber optic cable is very high but it is becoming very popular in the home networking and LANs also. In the local area networking, 10baseT/CAT5 cable is most commonly in use.
A server is a computer in network that provides services to the client computers such as logon requests processing, files access and storage, internet access, printing access and many other types of services. Servers are mostly equipped with extra hardware such as plenty of external memory (RAM), more data store capacity (hard disks), high processing speed and other features.
On the other hand if you need to build WAN, you will need to have routers, switches, dedicated or leased telephone lines such as ISDN lines, frame relay connection and other types of wan communication connections.
There are different communication mediums such as Ethernet cables, copper wire, coaxial cable, fiber optic cables, leased telephone lines and ever air is also a communication medium for the satellite communication. The most common networking medium is the LAN is the Ethernet cable (UTP/STP), which is used in the star topology. Hub is a central device of a network and every computer in a network is directly connected with the hub.
If the hub fails to work, the communication between the computers stops till the hub again starts working. Hub broadcasts the data to its every port, and then finding the destined computer, the data sent toward it. The switch is an advance form of the hub similar in functions but the advanced switches has a switching table in them. A advanced switch stores the MAC address of every attached computer and the data is only sent to the destined computer, unlike the hubs where data is sent to all ports. A router is a key device in the internet communication and wan communication system. A router has software called routing table and the source and destination addresses are stored in the routing table.
A router connects two logically and physically different networks. Router finds the IP address of the next hop (next router) and the data is sent toward it and so on. The well known routers developing companies are Cisco systems, Nortel, DLink and others. Every ISP, banks, corporate offices and multinational companies use routers for LAN and WAN communications and communication in their private networks. A gateway can be device or software in a network.
A gateway device connects the LAN with the internet. A gateway is directly exposed to the internet so it should be securely configured and in and out traffic should be monitored. If you are using DSL connection, you must need a DSL modem in your network. The telephone line is connected with the DSL modem and UTP/STP cable attaches your computer with the DSL modem. Modems are the devices that are used to modulate and demodulate the data. They convert analogue signals to digital and digital signals to analogue so that signals can travel on the telephone lines.
There are certain types of the cables that are used to connect two or more computers in a network. Fiber optic cable acts as a backbone between the ISPs and corporate offices. Data travels at the speed of light on the fiber optic cables. The cost and the installation cost of the fiber optic cable is very high but it is becoming very popular in the home networking and LANs also. In the local area networking, 10baseT/CAT5 cable is most commonly in use.
A server is a computer in network that provides services to the client computers such as logon requests processing, files access and storage, internet access, printing access and many other types of services. Servers are mostly equipped with extra hardware such as plenty of external memory (RAM), more data store capacity (hard disks), high processing speed and other features.
Computer Network Topology
Here you will learn network topology introduction, how computers get connected, bus, star, hub, hybrid, mesh, tree topologies and network physical design. In Computer Networking “topology” refers to the layout or design of the connected devices. Network Topologies can be physical or logical. In this section I will illustrate on the different types of the topologies.
1.Computer network topologies can be categorized in the following categories.
• bus
• star
• ring
• mesh
• Tree.
Hybrid networks are the complex networks, which can be built of two or more above mentioned topologies.
Bus Topology:
Bus topology uses a common backbone to connect all the network devices in a network in a linear shape. A single cable functions as the shared communication medium for all the devices attached with this cable with an interface connector. The device, which wants to communicate send the broadcast message to all the devices attached with the shared cable but only the intended recipient actually accepts and process that message.
Ethernet bus topologies are easy to install and don’t require much cabling and only a main shared cable is used for network communication. 10Base-2 and 10BaseT are two popular types of the Ethernet cables used in the Bus topology. Also, Bus network works with very limited devices. Performance issues are likely to occur in the Bus topology if more than 12-15 computers are added in a Bus Network. Additionally, if the Backbone cable fails then all network becomes useless and no communication fails among all the computers. Unlike in the Star topology in which if one computer is detached from a network then there is not effect on the other computers in a network.
Ring Topology:
In ring Network, every computer or devices has two adjacent neighbors for communication. In a ring network, all the communication messages travel in the same directory whether clockwise or anti clockwise. Any damage of the cable of any cable or device can result in the breakdown of the whole network. Ring topology now has become almost obsolete.
FDDI, SONET or Token Ring Technology can be used to implement Ring Technology. Ring topologies can be found in office, school or small buildings.
Star Topology:
In the computer networking world the most commonly used topology in LAN is the star topology. Star topologies can be implemented in home, offices or even in a building. All the computers in the star topologies are connected to central devices like hub, switch or router. The functionality of all these devices is different. I have covered the detail of each networking devices in the separate portion of my website. Computers in a network are usually connected with the hub, switch or router with the Unshielded Twisted Pair (UTP) or Shielded Twisted Pair Cables.
As compared to the bus topology, a star network requires more devices & cables to complete anetwork. The failure of each node or cable in a star network, won’t take down the entire network
as compared to the Bus topology.
However if the central connecting devices such as hub, switch or router fails due to any reason,then ultimately all the network can come down or collapse.
Tree Topology:
Tree topologies are comprised of the multiple star topologies on a bus. Tree topologies integrate multiple star topologies together onto a bus. Only the hub devices can connect directly with the tree bus and each Hub functions as a root of a tree of the network devices. This bus/star/hybrid combination supports future expandability of the computer networks, much better than a bus or star.
Mesh Topology:
Mesh topology work on the concept of routes. In Mesh topology, message sent to the destination can take any possible shortest, easiest route to reach its destination. In the previous topologies star and bus, messages are usually broadcasted to every computer, especially in bus topology. Similarly in the Ring topology message can travel in only one direction i.e clockwise or anticlockwise. Internet employs the Mesh topology and the message finds its route for its destination. Router works in find the routes for the messages and in reaching them to their destinations.The topology in which every devices connects to every other device is called a full Mesh topology unlike in the partial mesh in which every device is indirectly connected to the other devices.
Summary:
Topologies are the important part of the network design theory. A better network can be built if you have the knowledge of these topologies and if you know the difference between each topology. Similarly you should have the knowledge of each network device so that you can properly use them according to your network needs. A misconfigured network can result in a waste of time and energy as well as a lots of troubleshooting methods to resolve the issue. So thebasic understanding of the network topologies and network devices is a must to build a good network.
1.Computer network topologies can be categorized in the following categories.
• bus
• star
• ring
• mesh
• Tree.
Hybrid networks are the complex networks, which can be built of two or more above mentioned topologies.
Bus Topology:
Bus topology uses a common backbone to connect all the network devices in a network in a linear shape. A single cable functions as the shared communication medium for all the devices attached with this cable with an interface connector. The device, which wants to communicate send the broadcast message to all the devices attached with the shared cable but only the intended recipient actually accepts and process that message.
Ethernet bus topologies are easy to install and don’t require much cabling and only a main shared cable is used for network communication. 10Base-2 and 10BaseT are two popular types of the Ethernet cables used in the Bus topology. Also, Bus network works with very limited devices. Performance issues are likely to occur in the Bus topology if more than 12-15 computers are added in a Bus Network. Additionally, if the Backbone cable fails then all network becomes useless and no communication fails among all the computers. Unlike in the Star topology in which if one computer is detached from a network then there is not effect on the other computers in a network.
Ring Topology:
In ring Network, every computer or devices has two adjacent neighbors for communication. In a ring network, all the communication messages travel in the same directory whether clockwise or anti clockwise. Any damage of the cable of any cable or device can result in the breakdown of the whole network. Ring topology now has become almost obsolete.
FDDI, SONET or Token Ring Technology can be used to implement Ring Technology. Ring topologies can be found in office, school or small buildings.
Star Topology:
In the computer networking world the most commonly used topology in LAN is the star topology. Star topologies can be implemented in home, offices or even in a building. All the computers in the star topologies are connected to central devices like hub, switch or router. The functionality of all these devices is different. I have covered the detail of each networking devices in the separate portion of my website. Computers in a network are usually connected with the hub, switch or router with the Unshielded Twisted Pair (UTP) or Shielded Twisted Pair Cables.
As compared to the bus topology, a star network requires more devices & cables to complete anetwork. The failure of each node or cable in a star network, won’t take down the entire network
as compared to the Bus topology.
However if the central connecting devices such as hub, switch or router fails due to any reason,then ultimately all the network can come down or collapse.
Tree Topology:
Tree topologies are comprised of the multiple star topologies on a bus. Tree topologies integrate multiple star topologies together onto a bus. Only the hub devices can connect directly with the tree bus and each Hub functions as a root of a tree of the network devices. This bus/star/hybrid combination supports future expandability of the computer networks, much better than a bus or star.
Mesh Topology:
Mesh topology work on the concept of routes. In Mesh topology, message sent to the destination can take any possible shortest, easiest route to reach its destination. In the previous topologies star and bus, messages are usually broadcasted to every computer, especially in bus topology. Similarly in the Ring topology message can travel in only one direction i.e clockwise or anticlockwise. Internet employs the Mesh topology and the message finds its route for its destination. Router works in find the routes for the messages and in reaching them to their destinations.The topology in which every devices connects to every other device is called a full Mesh topology unlike in the partial mesh in which every device is indirectly connected to the other devices.
Summary:
Topologies are the important part of the network design theory. A better network can be built if you have the knowledge of these topologies and if you know the difference between each topology. Similarly you should have the knowledge of each network device so that you can properly use them according to your network needs. A misconfigured network can result in a waste of time and energy as well as a lots of troubleshooting methods to resolve the issue. So thebasic understanding of the network topologies and network devices is a must to build a good network.
Ethernet
In this section you will learn about the lan terminology, basic ethernet networking overview, a general introduction to LAN, introduction to IEEE, lan topologies, wan standards. You can also find these categories in this site such as network tutorials, computer networking guide, what is networking, tech study guides, topologies, what is data recovery, wireless communication, computer interview questions and network certification. The IEEE standards have been developed by the International Standards Organization (ISO). The Institute of Electrical and Electronic Engineers (IEEE) in 1985 produced a series of standards for the Local Area Networks, which are called IEEE 802 standards.
These standards have been accepted widely throughout the IT world. One of the IEEE 802 standards, the IEEE 802.3 is known as “Ethernet”. Ethernet is the most widely used LAN technology. Ethernet was developed by Xerox corporations in 1972 and it was the first LAN.
According to the ISO standards allows manufactures to produce the devices and equipments, which are guaranteed to operate anywhere.
The Ethernet in its simplest form uses a passive bus that operates at 10 Mbps. The bus is formed from the co-axial cable, which connects all the PCs in the LAN.
A single LAN may have 1024 attached computers, although in the real practice most LANS have fewer computers than this number. One or more segments of the co-axial cable are attached to end to end to create the Ethernet Cable Segment. Each segment is terminated by 50 ohm resistors.
In today’s IT world the reliable and timely access to the information has become vital. Today coworkers thousands of miles apart from each other can share data, voice, video etc with the fractions of seconds. Similarly a larger number of the coworkers can review the research data simultaneously. The Internet allows businesses to share information and resources with their customers.
Ethernet is a communication protocol that is embedded in software and hardware devices that intended. Ethernet has become the standard computer networking protocol with the help of the Xerox, Intel and Digital
A basic LAN consists of the following components.
• Two or more computers.
• Network Interface card or LAN Card in each PC.
• Ethernet cable (Cat5, UTP/SPT) cable to connect the two computers.
• A hub, switch or router to route or direct the network traffic.
• Software for the communication/computer networking.
A network interface card (NIC) is attached and installed in each PC and is assigned a unique address. An Ethernet cable is used to connect two computers; Ethernet cable has RJ45connectors at both ends. There can be two scenarios 1. Two computers can directly connect with each other or 2. Each computer is directly connected with the hub/switch and hence communication occurs in the network. The hub or switch acts as relay.
Computer Network can be wireless. Despite of using Ethernet cable for the communication, Wireless Network Interface cards use radio waves to communicate with the wireless switch or hub. A small antenna is used in the wireless NICs, switches and hubs. Although the wireless networks are more easy to use as compared to the cabled networks, but more configurations and extra care is required to setup and run a wireless network.
The alternate technologies to Ethernet are “Token Ring”, which is used in the Ring Topologiesnetworks. Token Ring is designed by the IBM and ATM. In ATM networking, devices are connected with each other over a very large distance (thus forms the WAN), and behaves like LANs.
Ethernet is a well established and widely used network standard for small to medium sized Ethernet networks as well as for other networks. Ethernet has been used over the 3 decades and forms a very excellent networking/communication environment.
Ethernet Terms
Ethernet follows a simple set of rules. To understand these rules its important to understand the
following terminology.
• Node – The devices that are attached to the segments are nodes.
• Frame – The nodes (computers or network devices) communicates in the form of short messages that are known as frames. The frames are chunks of information with variable size.
• Segment – A single shared medium is known as a Ethernet segment.
• Medium – The Ethernet devices are attached to a common medium. The frames of the data travel along with that medium. This medium can be coaxial cable. Today most commonly used communication mediums are UTP/STP cable, fiber optic cables.
Frames are analogous in human language. We have some rules for constructed the sentences. The
Ethernet protocol specifies a set of rules for constructing the frames. The frames length varies. Each frame must contain source and destination address for the identification of the recipient and the send of the message. The nodes can be uniquely and easily identified. Each Ethernet devices must have a single unique address.
Compute networking standards has brought a revolution in the network computing and it made the communication very easy and standarized. Now every computer and networking devices has to to follow the same standard to communicate with each other.
These standards have been accepted widely throughout the IT world. One of the IEEE 802 standards, the IEEE 802.3 is known as “Ethernet”. Ethernet is the most widely used LAN technology. Ethernet was developed by Xerox corporations in 1972 and it was the first LAN.
According to the ISO standards allows manufactures to produce the devices and equipments, which are guaranteed to operate anywhere.
The Ethernet in its simplest form uses a passive bus that operates at 10 Mbps. The bus is formed from the co-axial cable, which connects all the PCs in the LAN.
A single LAN may have 1024 attached computers, although in the real practice most LANS have fewer computers than this number. One or more segments of the co-axial cable are attached to end to end to create the Ethernet Cable Segment. Each segment is terminated by 50 ohm resistors.
In today’s IT world the reliable and timely access to the information has become vital. Today coworkers thousands of miles apart from each other can share data, voice, video etc with the fractions of seconds. Similarly a larger number of the coworkers can review the research data simultaneously. The Internet allows businesses to share information and resources with their customers.
Ethernet is a communication protocol that is embedded in software and hardware devices that intended. Ethernet has become the standard computer networking protocol with the help of the Xerox, Intel and Digital
A basic LAN consists of the following components.
• Two or more computers.
• Network Interface card or LAN Card in each PC.
• Ethernet cable (Cat5, UTP/SPT) cable to connect the two computers.
• A hub, switch or router to route or direct the network traffic.
• Software for the communication/computer networking.
A network interface card (NIC) is attached and installed in each PC and is assigned a unique address. An Ethernet cable is used to connect two computers; Ethernet cable has RJ45connectors at both ends. There can be two scenarios 1. Two computers can directly connect with each other or 2. Each computer is directly connected with the hub/switch and hence communication occurs in the network. The hub or switch acts as relay.
Computer Network can be wireless. Despite of using Ethernet cable for the communication, Wireless Network Interface cards use radio waves to communicate with the wireless switch or hub. A small antenna is used in the wireless NICs, switches and hubs. Although the wireless networks are more easy to use as compared to the cabled networks, but more configurations and extra care is required to setup and run a wireless network.
The alternate technologies to Ethernet are “Token Ring”, which is used in the Ring Topologiesnetworks. Token Ring is designed by the IBM and ATM. In ATM networking, devices are connected with each other over a very large distance (thus forms the WAN), and behaves like LANs.
Ethernet is a well established and widely used network standard for small to medium sized Ethernet networks as well as for other networks. Ethernet has been used over the 3 decades and forms a very excellent networking/communication environment.
Ethernet Terms
Ethernet follows a simple set of rules. To understand these rules its important to understand the
following terminology.
• Node – The devices that are attached to the segments are nodes.
• Frame – The nodes (computers or network devices) communicates in the form of short messages that are known as frames. The frames are chunks of information with variable size.
• Segment – A single shared medium is known as a Ethernet segment.
• Medium – The Ethernet devices are attached to a common medium. The frames of the data travel along with that medium. This medium can be coaxial cable. Today most commonly used communication mediums are UTP/STP cable, fiber optic cables.
Frames are analogous in human language. We have some rules for constructed the sentences. The
Ethernet protocol specifies a set of rules for constructing the frames. The frames length varies. Each frame must contain source and destination address for the identification of the recipient and the send of the message. The nodes can be uniquely and easily identified. Each Ethernet devices must have a single unique address.
Compute networking standards has brought a revolution in the network computing and it made the communication very easy and standarized. Now every computer and networking devices has to to follow the same standard to communicate with each other.
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