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perkakasan rangkaian

1.       Modem

a.       Perkakasan yang menukar isyarat digital kepada isyarat analog dan sebaliknya.

b.       Terdapat dua jenis modem iaitu modem luaran dan modem dalaman.

c.        Modem luaran adalah alat berasingan daripada komputer.

d.       Modem dalaman adalah expansion card yang boleh dimasukkan kepada expansion slot pada papan ibu komputer.

2.       Kad Antaramuka Rangkaian a.       Kad rangkaian dipasang ke dalam setiap komputer. b.       Ketika penghantaran maklumat di antara dua buah komputer dilakukan, maklumat yang akan dihantar akan melalui proses pengendalian. Kad rangkaian bertanggungjawab melakukan proses ini. c.        Kad antaramuka rangkaian mempunyai 3 kelajuan duplex penuh iaitu 10MB, 100MB dan 10/100MB.
3.       Hub a.       Berperanan untuk menghubungkan setiap komputer di dalam LAN. b.       Hub selalunya mengandungi 8, 12, 32 port untuk menyambungkan komputer-komputer atau alat-alat lain di dalam rangkaian. c.        Hub mempunyai 3 kelajuan duplex penuh iaitu 10MB, 100MB dan 10/100MB.
4.       Kabel a.       Talian sambungan di antara setiap peranti di dalam rangkaian merupakan kabel. b.       Dalam memainkan peranan sebagai perantara dalam penghantaran maklumat. c.        Spesifikasi kabel yang berbeza mempunyai kelajuan penghantaran yang berlainan.
5.       Repeater a.       Adalah sebuah alat yang menerima isyarat daripada media penghantaran, menguatkan semula isyarat tersebut dan menghantar semula isyarat berkenaan ke destinasinya.
6.       Bridges a.       Adalah sebuah alat yang menyambungkan 2 LAN yang menggunakan protokol yang sama seperti Ethernet.
7.       Routers a.       Adalah alat yang menyambungkan beberapa rangkaian termasuk rangkaian yang menggunakan protokol yang berbeza. b.       Ia adalah alat komunikasi pintar yang boleh membuat penghantaran data menggunakan laluan yang paling pantas.
8.       Gateways a.       Adalah kombinasi perkakasan dan perisian. b.       Kegunaanya adalah untuk menyamungkan rangkaian yang menggunakan protokol yang berbeza.

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topology

Network topology is the layout pattern of interconnections of the various elements (links, nodes, etc.) of a computer^[1][2] or biological network.^[3] Network topologies may be physical or logical. Physical topology refers to the physical design of a network including the devices, location and cable installation. Logical topology refers to how data is actually transferred in a network as opposed to its physical design. In general physical topology relates to a core network whereas logical topology relates to basic network.

Topology can be understood as the shape or structure of a network. This shape does not necessarily correspond to the actual physical design of the devices on the computer network. The computers on a home network can be arranged in a circle but it does not necessarily mean that it represents a ring topology.

Any particular network topology is determined only by the graphical mapping of the configuration of physical and/or logical connections between nodes. The study of network topology uses graph theory. Distances between nodes, physical interconnections, transmission rates, and/or signal types may differ in two networks and yet their topologies may be identical.

A local area network (LAN) is one example of a network that exhibits both a physical topology and a logical topology. Any given node in the LAN has one or more links to one or more nodes in the network and the mapping of these links and nodes in a graph results in a geometric shape that may be used to describe the physical topology of the network. Likewise, the mapping of the data flow between the nodes in the network determines the logical topology of the network. The physical and logical topologies may or may not be identical in any particular network.

IP ADDRESS

An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.^[1] An IP address serves two principal functions: host or network interfaceidentification and location addressing. Its role has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there."^[2]

The designers of the Internet Protocol defined an IP address as a 32-bit number^[1] and this system, known as Internet Protocol Version 4(IPv4), is still in use today. However, due to the enormous growth of the Internet and the predicted depletion of available addresses, a new addressing system (IPv6), using 128 bits for the address, was developed in 1995,^[3] standardized as RFC 2460 in 1998,^[4] and itsdeployment has been ongoing since the mid-2000s.

IP addresses are binary numbers, but they are usually stored in text files and displayed in human-readable notations, such as 172.16.254.1 (for IPv4), and 2001:db8:0:1234:0:567:8:1 (for IPv6).

The Internet Assigned Numbers Authority (IANA) manages the IP address space allocations globally and delegates five regional Internet registries (RIRs) to allocate IP address blocks to local Internet registries (Internet service providers) and other entities.

MOTHERBOARD

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In personal computers, a motherboard is the central printed circuit board (PCB) in many moderncomputers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple computers, the logic board.^[1] It is also sometimes casually shortened to mobo.

Motherboard for an Acer desktop personal computer, showing the typical components and interfaces that are found on a motherboard. This model was made by Foxconn in 2008, and follows the ATX layout (known as the "form factor") usually employed for desktop computers. It is designed to work with AMD's Athlon 64 processor.

[edit] History

Prior to the advent of the microprocessor, a computer was usually built in a card-cage case ormainframe with components connected by a backplane consisting of a set of slots themselves connected with wires; in very old designs the wires were discrete connections between card connector pins, but printed circuit boards soon became the standard practice. The Central Processing Unit, memory and peripherals were housed on individual printed circuit boards which plugged into the backplate. During the late 1980s and 1990s, it became economical to move an increasing number of peripheral functions onto the motherboard (see below). In the late 1980s, motherboards began to include single ICs (called Super I/O chips) capable of supporting a set of low-speed peripherals: keyboard, mouse, floppy disk drive, serial ports, and parallel ports. As of the late 1990s, many personal computer motherboards supported a full range of audio, video, storage, and networking functions without the need for any expansion cards at all; higher-end systems for 3Dgaming and computer graphics typically retained only the graphics card as a separate component.
The early pioneers of motherboard manufacturing were Micronics, Mylex, AMI, DTK, Hauppauge,Orchid Technology, Elitegroup, DFI, and a number of Taiwan-based manufacturers.
The most popular computers such as the Apple II and IBM PC had published schematic diagrams and other documentation which permitted rapid reverse-engineering and third-party replacement motherboards. Usually intended for building new computers compatible with the exemplars, many motherboards offered additional performance or other features and were used to upgrade the manufacturer's original equipment
The term mainboard is applied to devices with a single board and no additional expansions or capability. In modern terms this would include embedded systems and controlling boards in televisions, washing machines, etc. A motherboard specifically refers to a printed circuit board with expansion capability.

[edit] Overview

A motherboard, like a backplane, provides the electrical connections by which the other components of the system communicate, but unlike a backplane, it also connects the central processing unit and hosts other subsystems and devices.
A typical desktop computer has its microprocessor, main memory, and other essential components connected to the motherboard. Other components such as external storage, controllers for videodisplay and sound, and peripheral devices may be attached to the motherboard as plug-in cards or via cables, although in modern computers it is increasingly common to integrate some of these peripherals into the motherboard itself.
An important component of a motherboard is the microprocessor's supporting chipset, which provides the supporting interfaces between the CPU and the various buses and external components. This chipset determines, to an extent, the features and capabilities of the motherboard.
Modern motherboards include, at a minimum:

• sockets (or slots) in which one or more microprocessors may be installed^[2]
• slots into which the system's main memory is to be installed (typically in the form ofDIMM modules containing DRAM chips)
• a chipset which forms an interface between the CPU's front-side bus, main memory, and peripheral buses
• non-volatile memory chips (usually Flash ROM in modern motherboards) containing the system's firmware or BIOS
• a clock generator which produces the system clock signal to synchronize the various components
• slots for expansion cards (these interface to the system via the buses supported by the chipset)
• power connectors, which receive electrical power from the computer power supply and distribute it to the CPU, chipset, main memory, and expansion cards.^[3]

The Octek Jaguar V motherboard from 1993.^[4] This board has few onboard peripherals, as evidenced by the 6 slots provided for ISA cards and the lack of other built-in external interface connectors.

Additionally, nearly all motherboards include logic and connectors to support commonly used input devices, such as PS/2 connectors for a mouse and keyboard. Early personal computers such as theApple II or IBM PC included only this minimal peripheral support on the motherboard. Occasionally video interface hardware was also integrated into the motherboard; for example, on the Apple II and rarely on IBM-compatible computers such as the IBM PC Jr. Additional peripherals such as disk controllers and serial ports were provided as expansion cards.
Given the high thermal design power of high-speed computer CPUs and components, modern motherboards nearly always include heat sinks and mounting points for fans to dissipate excess heat.

[edit] CPU sockets

Main article: CPU socket

A CPU socket or slot is an electrical component that attaches to a printed circuit board (PCB) and is designed to house a CPU (also called a microprocessor). It is a special type of integrated circuit socket designed for very high pin counts. A CPU socket provides many functions, including a physical structure to support the CPU, support for a heat sink, facilitating replacement (as well as reducing cost), and most importantly, forming an electrical interface both with the CPU and the PCB. CPU sockets can most often be found in most desktop and server computers (laptops typically use surface mount CPUs), particularly those based on the Intel x86 architecture on the motherboard. A CPU socket type and motherboard chipset must support the CPU series and speed.

[edit] Integrated peripherals

Block diagram of a modern motherboard, which supports many on-board peripheral functions as well as several expansion slots.

With the steadily declining costs and size of integrated circuits, it is now possible to include support for many peripherals on the motherboard. By combining many functions on one PCB, the physical size and total cost of the system may be reduced; highly integrated motherboards are thus especially popular in small form factor and budget computers.
For example, the ECS RS485M-M,^[5] a typical modern budget motherboard for computers based onAMD processors, has on-board support for a very large range of peripherals:

• disk controllers for a floppy disk drive, up to 2 PATA drives, and up to 6 SATA drives (including RAID 0/1 support)
• integrated graphics controller supporting 2D and 3D graphics, with VGA and TV output
• integrated sound card supporting 8-channel (7.1) audio and S/PDIF output
• Fast Ethernet network controller for 10/100 Mbit networking
• USB 2.0 controller supporting up to 12 USB ports
• IrDA controller for infrared data communication (e.g. with an IrDA-enabled cellular phone or printer)
• temperature, voltage, and fan-speed sensors that allow software to monitor the health of computer components

Expansion cards to support all of these functions would have cost hundreds of dollars even a decade ago; however, as of April 2007 such highly integrated motherboards are available for as little as $30 in the US.

[edit] Peripheral card slots

A typical motherboard of 2009 will have a different number of connections depending on its standard.
A standard ATX motherboard will typically have one PCI-E 16x connection for a graphics card, two conventional PCI slots for various expansion cards, and one PCI-E 1x (which will eventually supersede PCI). A standard EATX motherboard will have one PCI-E 16x connection for a graphics card, and a varying number of PCI and PCI-E 1x slots. It can sometimes also have a PCI-E 4x slot. (This varies between brands and models.)
Some motherboards have two PCI-E 16x slots, to allow more than 2 monitors without special hardware, or use a special graphics technology called SLI (for Nvidia) and Crossfire (for ATI). These allow 2 graphics cards to be linked together, to allow better performance in intensive graphical computing tasks, such as gaming and video editing.
As of 2007, virtually all motherboards come with at least four USB ports on the rear, with at least 2 connections on the board internally for wiring additional front ports that may be built into the computer's case. Ethernet is also included. This is a standard networking cable for connecting the computer to a network or a modem. A sound chip is always included on the motherboard, to allow sound output without the need for any extra components. This allows computers to be far moremultimedia-based than before. Some motherboards contain video outputs on the back panel for integrated graphics solutions (either embedded in the motherboard, or combined with the microprocessor, such as the Intel HD Graphics). A separate card may still be used.

[edit] Temperature and reliability

Main article: Computer cooling

Motherboards are generally air cooled with heat sinks often mounted on larger chips, such as theNorthbridge, in modern motherboards. Insufficient or improper cooling can cause damage to the internal components of the computer and cause it to crash. Passive cooling, or a single fan mounted on the power supply, was sufficient for many desktop computer CPUs until the late 1990s; since then, most have required CPU fans mounted on their heat sinks, due to rising clock speeds and power consumption. Most motherboards have connectors for additional case fans as well. Newer motherboards have integrated temperature sensors to detect motherboard and CPU temperatures, and controllable fan connectors which the BIOS or operating system can use to regulate fan speed. Some computers (which typically have high-performance microprocessors, large amounts of RAM, and high-performance video cards) use a water-cooling system instead of many fans.
Some small form factor computers and home theater PCs designed for quiet and energy-efficient operation boast fan-less designs. This typically requires the use of a low-power CPU, as well as careful layout of the motherboard and other components to allow for heat sink placement.
A 2003 study^[6] found that some spurious computer crashes and general reliability issues, ranging from screen image distortions to I/O read/write errors, can be attributed not to software or peripheralhardware but to aging capacitors on PC motherboards. Ultimately this was shown to be the result of a faulty electrolyte formulation.^[7]

A microATX motherboard with some faulty capacitors.

For more information on premature capacitor failure on PC motherboards, see capacitor plague.

Motherboards use electrolytic capacitors to filter the DC power distributed around the board. These capacitors age at a temperature-dependent rate, as their water based electrolytes slowly evaporate. This can lead to loss of capacitance and subsequent motherboard malfunctions due to voltageinstabilities. While most capacitors are rated for 2000 hours of operation at 105 °C,^[8] their expected design life roughly doubles for every 10 °C below this. At 45 °C a lifetime of 15 years can be expected. This appears reasonable for a computer motherboard. However, many manufacturers have delivered substandard capacitors,^[9] which significantly reduce life expectancy. Inadequate case cooling and elevated temperatures easily exacerbate this problem. It is possible, but tedious and time