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Router adalah peralatan yang melakukan fungsi routing, router bisa menjalankan tugasnya dikarenakan konfigurasi yang dibuat, pada saat kita akan melakukan konfigurasi dan masuk melaui console maka pada router cisco tersebut terdapat 3 mode, yaitu user mode, privilege mode, dan global configuration mode. Kita perlu memahami perbedaan mode ini pada saat mengkonfigurasi router sehingga kita akan tahu berada di mode manakah kita pada saat melakukan konfigurasi dan apa yang bisa kita lakukan pada  mode tersebut.
Mode-mode pada router
Pada saat kita melakukan konfigurasi pada Router Cisco banyak perintah atau command yang terdapat  pada setiap mode, dimana perintah tersebut ada pada suatu mode tetapi tidak terdapat pada mode lain
ModePromptPenggunaan
User ModeRouter>Pada saat kita pertama kali login melalui console maka kita akan masuk ke user mode, dimana pada mode ini kita tidak dapat melakukan konfigurasi, pada mode ini kita hanya dapat melihat informasi dasar dari router, dan untuk melihat perintah apa yang tersedia pada mode ini ketikkan perintah show ?
Privileged ModeRouter#Dari user mode untuk masuk ke privilege mode ketikkan perintahenable dan untuk kembali ke user mode ketikkan perintah disable pada mode ini kita bisa melihat informasi routing, interface protocol, konfigurasi yang sedang berjalan, konfigurasi yang disimpan, dan sedikit konfigurasi misal mengatur clock pada router. Untuk melihat perintah yang tersedia pda mode ini ketikkan perintah show ?
Global Configuration ModeRouter(config#)Untuk masuk ke mode ini pada privilege mode ketikkan perintahconfigure terminal dan pada mode ini kita mulai bisa melakukan konfigurasi antara lain: mengubah hostname, mengubah password, melakukan konfigurasi access list dan lain-lain, dan untuk melihat perintah yang tersedia pada mode ini ketikkan perintah show ?
Dari mode ini jugalah kita bisa masuk ke mode yang lebih spesifik misalnya masuk ke interface mode, mode untuk melakukan konfigurasi routing dan lain-lain
Setelah kita memahami mode inilah maka kita akan mengerti apa yang bisa kita lakukan pada setiap mode pada saat melakukan konfigurasi router dan mengerti susunan hirarki mode pada Cisco Router. Untuk bisa lebih memahami mari kita lihat contoh dibawah ini.
Pada saat pertama kali masuk ke console router mode pertama yang akan kita temui adalah user mode yang ditandai dengan tanda Router>
Router>
Untuk melihat daftar perintah yang tersedia pada mode ini cukup ketikkan tanda tanya “?” tanpa harus menekan enter.
Router>?
Exec commands:
<1-99>      Session number to resume
connect          Open a terminal connection
disable            Turn off privileged commands
disconnect      Disconnect an existing network connection
enable            Turn on privileged commands
exit                 Exit from the EXEC
logout             Exit from the EXEC
ping                Send echo messages
resume           Resume an active network connection
show              Show running system information
ssh                 Open a secure shell client connection
telnet              Open a telnet connection
terminal          Set terminal line parameters
traceroute       Trace route to destination
Router>
Dari user mode tingkatan mode berikutnya adalah Privileged Mode, untuk masuk ke Privileged Mode ketikkan perintah enable dan tekan enter.
Router>enable
Perhatikan promt sudah berubah dari Router> menjadi Router#
Router#
Sama seperti sebelumnya untuk melihat daftar perintah yang terdapat pada mode ini ketikkan tanda tanya “?
Router#?
Exec commands:
<1-99>      Session number to resume
auto                Exec level Automation
clear               Reset functions
clock              Manage the system clock
configure        Enter configuration mode
connect          Open a terminal connection
copy               Copy from one file to another
debug             Debugging functions (see also ‘undebug’)
delete             Delete a file
dir                  List files on a filesystem
disable            Turn off privileged commands
disconnect      Disconnect an existing network connection
enable            Turn on privileged commands
erase              Erase a filesystem
exit                 Exit from the EXEC
logout             Exit from the EXEC
mkdir             Create new directory
more              Display the contents of a file
no                  Disable debugging informations
ping                Send echo messages
reload             Halt and perform a cold restart
–More–
Tekan enter jika ingin melihat daftar perintah selanjutnya dan jika ingin kembali ke prompt Router#cukup menekan sembarang tombol pada keyboard komputer
Dari Privileged Mode kita bisa masuk ke mode yang lebih tinggi yaitu Global Configuration Mode dan untuk masuk ke mode ini kita cukup mengetikkan perintah configure terminal dan tekan enter
Router#configure terminal
Perhatikan kembali bahwa prompt sudah berubah dari Router# menjadi Router(config)#
Router(config)#
Untuk melihat daftar perintah pada Gobal Configuration Mode, ketikkan tanda tanya “?
Router(config)#?
Configure commands:
aaa                             Authentication, Authorization and Accounting.
access-list                   Add an access list entry
banner                        Define a login banner
boot                           Modify system boot parameters
cdp                                        Global CDP configuration subcommands
class-map                   Configure Class Map
clock                          Configure time-of-day clock
config-register Define the configuration register
crypto                        Encryption module
dial-peer                     Dial Map (Peer) configuration commands
do                              To run exec commands in config mode
dot11                         IEEE 802.11 config commands
enable                        Modify enable password parameters
end                             Exit from configure mode
ephone                       define ethernet phone
ephone-dn                  Configure ephone phone lines (Directory Numbers)
exit                             Exit from configure mode
hostname                    Set system’s network name
interface                     Select an interface to configure
ip                               Global IP configuration subcommands
ipv6               Global IPv6 configuration commands
–More–
Sama seperti dengan keterangan sebelumnya jika ingin melihat daftar perintah selanjutnya silahkan tekan enter dan jika ingin kembali ke prompt Router(config)# cukup menekan sembarang tombol pada keyboard komputer.
Ini merupakan hal yang sangat penting untuk dipahami sebab dengan mengerti pada mode apa kita berada maka kita akan mengerti perintah apa yang bisa kita jalankan dan konfigurasi apa yang bisa kita buat.
Global Configuration Mode merupakan mode konfigurasi utama dan kenapa disebut dengan konfigurasi utama sebab dari mode inilah kita bisa masuk ke mode-mode konfigurasi yang lebih spesifik, misal kita ingin melakukan konfigurasi pada interface seperti pemberian IP addres dan lain-lain maka kita harus masuk lagi ke mode yang lebih spesifik untuk melakukan konfigurasi tersebut yaitu interface mode. Spesifik-spesifik mode itu antara lain:
  • Interface mode
  • Line mode
  • Router mode
  • Subinterface mode
  • Controller mode
Misal kita ingin melakukan konfigurasi pada interface dan melihat daftar interface apa yang bisa kita konfigurasi cukup kita ketikkan Router(config)#interface ? maka akan terlihat daftar interface yang bisa kita konfigurasi. Penggunaan tanda tanya “?” merupakan perintah yang sangat membantu kita dalam mengetahui daftar perintah yang tersedia pada suatu mode maupun mengetahui daftar perintah yang mengikuti suatu perintah, sebab biasanya perintah pada Cisco merupakan suatu rangkaian perintah dalam artian setelah perintah tersebut sebenarnya ada perintah lain yang mengikuti perintah tersebut, untuk memeriksa apakah perintah tersebut masih ada yang mengikutinya periksalah dengan perintah “?”
Router(config)#interface ?
Async              Async interface
BRI                              ISDN Basic Rate Interface
BVI                              Bridge-Group Virtual Interface
CTunnel                       CTunnel interface
Dialer                           Dialer interface
FastEthernet                 FastEthernet IEEE 802.3
Group-Async               Async Group interface
Lex                              Lex interface
Loopback                    Loopback interface
MFR                            Multilink Frame Relay bundle interface
Multilink          Multilink-group interface
Null                              Null interface
Tunnel             Tunnel interface
Vif                                PGM Multicast Host interface
Virtual-Template           Virtual Template interface
Virtual-TokenRing        Virtual TokenRing
range                            interface range command
Terlihat disitu daftar perintah yang mengikuti perintah Interface, sekarang kita ambil contoh perintah FastEthernet dan jika ingin melihat nomor interface FastEthernet yang bisa kita konfigurasi cukup dengan mengetikkan perintah “?“lagi.
Router(config)#interface fastEthernet ?
<0-9>  FastEthernet interface number
Router(config)#interface fastEthernet 0?
/
Router(config)#interface fastEthernet 0/?
<0-24>  FastEthernet interface number
Router(config)#interface fastEthernet 0/0 ?
<cr>
<cr> merupakan singkatan dari carriage return atau dalam pengertian kita telah mencapai  ujung akhir dari rangkaian perintah tersebut, atau bisa kita katakan bahwa tidak ada lagi perintah yang mengikuti perintah tersebut dan kita bisa menekan enter.
Router(config)#interface fastEthernet 0/0
Router(config-if) #
Perhatikan kembali bahwa prompt sudah berubah dari Router(config)# menjadi Router(config-if)# dan ini menyatakan bahwa kita berada pada Interface Mode.
Jika kita ingin keluar dari Interface Mode dan kembali ke Global Configuration Mode ketikkan perintah exit kemudian enter
Router(config-if)#exit
Router(config)#
Seperti sudah dibahas sebelumnya bahwa Global Configuration Mode merupakan gerbang untuk menuju mode yang lebih spesifik, selain dari interface mode, terdapat juga antara lain line mode yang dipergunakan antara lain untuk mengatur password console, telnet, maupun aux.
Dari Global Configuration Mode ketik perintah line diikuti tanda tanya “?” maka terlihat perintah yang mengikuti perintah line
Router(config)#line ?
<0-70>   First Line number
aux                Auxiliary line
console          Primary terminal line
tty                 Terminal controller
vty                 Virtual terminal
Router(config)#line console ?
<0-0>  First Line number
Router(config)#line console 0 ?
<cr>
Router(config)#line console 0
Router(config-line)#
Perhatikan kembali bahwa prompt sudah berubah dari Router(config)# menjadi Router(config-line)#
Sekarang kita sudah berada pada Line Mode dan untuk kembali ke Global Configuration Mode ketik exit
Router(config-line)#
Router(config-line)#exit
Router(config)#
Untuk masuk ke  Line Mode yang lainnya sepeti telnet langkah yang kita perlukan sama dengan langkah yang diatas, manfaatkan “?” untuk menemukan perintah selanjutnya.
Router(config)#line vty 0 1180
Router(config-line)#
Untuk kembali ke Global Configuration Mode ketik exit
Router(config-line)#exit
Router(config)#
Untuk masuk ke Router Mode ketik router kemudian periksa dengan “?” apakah ada perintah yang mengikutinya seperti perintah dibawah ini.
Router(config)#router ?
bgp    Border Gateway Protocol (BGP)
eigrp  Enhanced Interior Gateway Routing Protocol (EIGRP)
ospf    Open Shortest Path First (OSPF)
rip      Routing Information Protocol (RIP)
Kita ambil contoh satu misalnya RIP kemudian pergunakan “?“untuk memeriksa apakah ada perintah setelah RIP
Router(config)#router rip ?
<cr>
Muncul <cr> atau carriage return berarti kita berada pada ujung akhir perintah dan kita bisa menekan enter
Router(config)#router rip
Router(config-router)#
Perhatikan kembali bahwa prompt sudah berubah dari Router(config)# menjadi Router(config-router)#
Dari Router Mode untuk kembali ke Global Configuration Mode ketik exit
Router(config-router)#exit
Ketik exit sekali lagi untuk kembali ke privileged mode
Router(config)#exit
%SYS-5-CONFIG_I: Configured from console by console
Router#
Kita bisa kembali ke privileged mode tanpa harus kembali lagi ke Global Configuration Mode dengan cara menekan ctrl+z yang pengertiannya kita menekan tombol ctrl pada keyboard disertai dengan menekan tombol huruf z
Router(config-router)#ctrl+z
Router#
Maka kita akan berada pada privileged mode.

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Explain IT industry certifications.
This course is focused on the following two industry-standard certifications:
       -          CompTIA A+
       -          European Certification of Informatics Professional (EUCIP) IT Administrator Certification (Modules 1 and 2)

After completing this section, you will meet these objectives:
      -          Identify education and certifications.
      -          Describe the A+ Certification.
      -     Describe the EUCIP Certification.
Identify education and certifications.
Information Technology (IT) is a term that encompasses the relationship between hardware, software, networks, and technical assistance provided to users.
This course covers the following topics:
      -          Personal computers
      -          Safe lab procedures
      -          Troubleshooting
      -          Operating systems
      -          Laptop computers
      -          Printers and scanners
      -          Networks
      -          Security
      -          Communication skills
A technician may continue to study and earn the following certifications:
      -          CCNA – Cisco Certified Networking Associate
      -          CCNP – Cisco Certified Networking Professional
      -          CCIE – Cisco Certified Internetworking Expert
      -          CISSP – Certified Information Systems Security Professional
      -          MCP – Microsoft Certified Professional
      -          MCSA – Microsoft Certified Systems Administrator
      -          MCSE – Microsoft Certified Systems Engineer
      -          Network+ – CompTIA Network Certification
      -          Linux+ – CompTIA Linux Certification

Describe the EUCIP certification.
 The EUCIP IT Administrator program offers a recognized certification of competence in IT.
The EUCIP IT Administrator Certification consists of five modules, with a corresponding exam for each module. This course will prepare you for Modules 1 and 2.
      -          Module 1: PC Hardware
The PC Hardware module requires that the candidate understand the basic makeup of a personal computer and the functions of the components.
       -          Module 2: Operating Systems
The Operating Systems module requires that the candidate be familiar with the procedures for installing and updating most common operating systems and applications.
      -          Module 3: Local Area Network and Network Services
The Local Area Network and Network Services module requires that the candidate be familiar with the procedure of installing, using, and managing local area networks. The candidate should be able to add and remove users and shared resources. The candidate should know how to use system tools for troubleshooting and repairing networks.
       -          Module 4: Expert Network Use
This module is beyond the scope of the IT Essentials course, although some of the topics are covered. The Expert Network Use module requires that the candidate understand LAN communication.
       -          Module 5: IT Security
This module is beyond the scope of the IT Essentials course, although some of the topics are covered. The IT Security module requires that the candidate be familiar with security methods and features that are available for a standalone or networked computer.

Describe cases   
A computer case contains the framework to support the internal components of a computer while providing an enclosure for added protection.
Computer cases are referred to in a number of ways:
-          Computer chassis
-          Cabinet
-          Tower
-          Box
-          Housing
There are many factors that must be considered when choosing a case:
-          The size of the motherboard
-          The number of external or internal drive locations called bays
-          Available space.

Power Supply is a hardware device that serves to supply power directly to the chassis kekomponen requiring voltage.
Describe power supplies          
Power Supply is a hardware device that serves to supply power directly to the chassis kekomponen requiring voltage.
Connectors
Different connectors are used to connect specific components to various ports on the motherboard:
-          A Molex connector is a keyed connector used to connect to an optical drive or a hard drive.
-          A Berg connector is a keyed connector used to connect to a floppy drive. A Berg connector is smaller than a Molex connector.
-          A 20-pin or 24-pin slotted connector is used to connect to the motherboard. The 24-pin slotted connector has two rows of 12 pins each, and the 20-pin slotted connector has two rows of 10 pins each.
-          A 4-pin to 8-pin auxiliary power connector has two rows of two to four pins and supplies power to all areas of the motherboard. The 4-pin to 8-pin auxiliary power connector is the same shape as the main power connector, but smaller.
Electricity and Ohm's Law
These are the four basic units of electricity:
-          Voltage (V)
-          Current (I)
-          Power (P)
-          Resistance (R)
Voltage, current, power, and resistance are electronic terms that a computer technician must know:
Voltage is a measure of the force required to push electrons through a circuit.
Power is a measure of the pressure required to push electrons through a circuit, called voltage, multiplied by the number of electrons going through that circuit, called current.
Resistance is the opposition to the flow of current in a circuit. Resistance is measured in ohms.
Identify the names, purposes, and characteristics of motherboards 
The motherboard is the main printed circuit board and contains the buses, or electrical pathways, found in a computer.
Identify the names, purposes, and characteristics of CPUs           
The central processing unit (CPU) is considered the brain of the computer.
 There are two major CPU architectures related to instruction sets:
-          Reduced Instruction Set Computer (RISC) : Architectures use a relatively small set of instructions, and RISC chips are designed to execute these instructions very rapidly.
-          Complex Instruction Set Computer (CISC) : Architectures use a broad set of instructions, resulting in fewer steps per operation.
 The speed of a CPU is rated in cycles per second. The speed of current CPUs is measured in millions of cycles per second, called megahertz (MHz), or billions of cycles per second, called gigahertz (GHz).Current processors have a 32-bit or a 64-bit processor data bus.
Overclocking is a technique used to make a processor work at a faster speed than its original specification.
MMX is a set of multimedia instructions built into Intel processors.
The latest processor technology has resulted in CPU manufacturers finding ways to incorporate more than one CPU core onto a single chip. Figure 2 lists the most common multiple core processors. These CPUs are capable of processing multiple instructions concurrently:
-          Single Core CPU : One core inside a single CPU that handles all of the processing capability. A motherboard manufacturer may provide sockets for more than one single processor, providing the ability to build a powerful, multi-processor computer.
-          Dual Core CPU : Two cores inside a single CPU in which both cores can process information at the same time.
-          Triple Core CPU : Three cores inside a single CPU that is actually a quad-core processor with one of the cores disabled.
-          Quad Core CPU : Four cores inside a single CPU in which all cores can process information simultaneously for enhanced software applications.
Identify the names, purposes, and characteristics of ROM and RAM        
-          ROM
Read-only memory (ROM) chips are located on the motherboard. ROM chips contain instructions that can be directly accessed by the CPU. Basic instructions for booting the computer and loading the operating system are stored in ROM.
-          RAM
Random access memory (RAM) is the temporary storage for data and programs that are being accessed by the CPU. RAM is volatile memory, which means that the contents are erased when the computer is powered off.
-          Memory Modules
Early computers had RAM installed on the motherboard as individual chips.
Double Data Rate (DDR) technology doubles the maximum bandwidth of SDRAM. DDR2 offers faster performance while using less energy. DDR3 operates at even higher speeds than DDR2; however, none of these DDR technologies are backward- or forward-compatible. See Figure 4 for a chart comparing different memory types and speeds.
Cache
SRAM is used as cache memory to store the most frequently used data. SRAM provides the processor with faster access to the data than retrieving it from the slower DRAM, or main memory.
Identify the names, purposes, and characteristics of adapter cards  
Adapter cards are used to expand and customize the capability of the computer:
-          Network Interface Card (NIC) : Connects a computer to a network using a network cable
-          Wireless NIC : Connects a computer to a network using radio frequencies
-          Sound adapter : Provides audio capability
-          Video adapter :  Provides graphic capability
-          Capture card : Sends a video signal to a computer so that the signal can be recorded to the computer hard drive with Video Capture software
-          TV tuner :  Provides the ability to watch and record TV signals on a PC by connecting a TV source, such as cable TV, satellite, or an antenna, to the installed tuner card
-          Modem adapter : Connects a computer to the Internet using a phone line
-          Small Computer System Interface (SCSI) adapter : Connects SCSI devices, such as hard drives or tape drives, to a computer
-          Redundant Array of Independent Disks (RAID) adapter : Connects multiple hard drives to a computer to provide redundancy and to improve performance
-          Universal Bus port (USB) Serial: Menghubungkan komputer ke perangkat peripheral
-          Port paralel: Menghubungkan komputer ke perangkat peripheral
-          Serial port: Menghubungkan komputer ke perangkat peripheral
Identify the names, purposes, and characteristics of storage drives        
Here are some common types of storage drives:

Floppy drive
Hard drive
Optical drive
Flash drive
Floppy Drive

A floppy drive, or floppy disk drive, is a storage device that uses removable 3.5-inch floppy disks.

Hard Drive
A hard drive, or hard disk drive, is a magnetic storage device that is installed inside the computer. The hard drive is used as permanent storage for data.

Optical Drive
An optical drive is a storage device that uses lasers to read data on the optical media. There are three types of optical drives:

Compact Disc (CD)
Digital versatile Disc (DVD)
Blu-ray Disc (BD)


There are several types of optical media:

-          CD-ROM   CD read-only memory media that is pre-recorded.
-          CD-R   CD recordable media that can be recorded one time.
-          CD-RW   CD rewritable media that can be recorded, erased, and re-recorded.
-          DVD-ROM   DVD read-only memory media that is pre-recorded.
-          DVD-RAM   DVD random access memory media that can be recorded, erased, and re-recorded.
-          DVD+/-R   DVD recordable media that can be recorded one time.
-          DVD+/-RW   DVD rewritable media that can be recorded, erased, and re-recorded.
-          BD-ROM   BD read-only media that is pre-recorded with movies, games, or software.
-          BD-R   BD recordable media that can record HD video and PC data storage one time.
-          BD-RE   BD rewritable format for HD video recording and PC data storage.
External Flash Drive
An external flash drive, also known as a thumb drive, is a removable storage device that connects to a USB port.
Types of Drive Interfaces
Here are some common drive interfaces:
-          IDE   Integrated Drive Electronics.
-          EIDE   Enhanced Integrated Drive Electronics.
-          PATA  
-          SATA  
-          eSATA
-          SCSI
RAID provides a way to store data across multiple hard disks for redundancy. To the operating system, RAID appears as one logical disk. See Figure 2 for a comparison of the different RAID levels. The following terms describe how RAID stores data on the various disks:
-          Parity   A method used to detect data errors.
-          Striping   A method used to write data across multiple drives.
-          Mirroring   A method of storing duplicate data to a second drive.
Identify the names, purposes, and characteristics of ports and cables      
Input/output (I/O) ports on a computer connect peripheral devices, such as printers, scanners, and portable drives. The following ports and cables are commonly used:
-          Serial
-          USB
-          FireWire
-          Parallel
-          SCSI
-          Network
-          PS/2
-          Audio
-          Video
Serial Ports and Cables
The serial cable used to connect an external modem to a computer.
USB Ports and Cables
The Universal Serial Bus (USB) is a standard interface that connects peripheral devices to a computer.
FireWire Ports and Cables
FireWire is a high-speed, hot-swappable interface that connects peripheral devices to a computer.
Parallel Ports and Cables
A parallel port on a computer is a standard Type A DB-25 female connector.
SCSI Ports and Cables
A SCSI port can transmit parallel data at rates in excess of 320 MBps and can support up to 15 devices.
Network Ports and Cables
A network port, also known as an RJ-45 port, connects a computer to a network.
PS/2 Ports
A PS/2 port connects a keyboard or a mouse to a computer.
Audio Ports
An audio port connects audio devices to the computer.
Video Ports and Connectors
There are several video port and connector types:
-          Video Graphics Array (VGA)   VGA has a 3-row, 15-pin female connector and provides analog output to a monitor.
-          Digital Visual Interface (DVI)   DVI has a 24-pin female connector or a 29-pin female connector and provides an uncompressed digital output to a monitor. DVI-I provides both analog and digital signals. DVI-D provides digital signals only.
-          High-Definition Multimedia Interface (HDMi)   HDMi has a 19-pin connector and provides digital video and digital audio signals.
-          S-Video   S-Video has a 4-pin connector and provides analog video signals.
-          Component/RGB   RGB has three shielded cables (red, green, blue) with RCA jacks and provides analog video signals.
Identify the names, purposes, and characteristics of input devices  
Here are some examples of input devices:
-          Mouse and keyboard
-          Digital camera and digital video camera
-          Biometric authentication device
-          Touch screen
-          Scanner
The mouse and keyboard are the two most commonly used input devices. The mouse is used to navigate the graphical user interface (GUI). The keyboard is used to enter text commands that control the computer.
A keyboard, video, mouse (KVM) switch is a hardware device that can be used to control more than one computer using a single keyboard, monitor, and mouse.
Digital cameras and digital video cameras, create images that can be stored on magnetic media. The image is stored as a file that can be displayed, printed, or altered.
Biometric identification makes use of features that are unique to an individual user, such as fingerprints, voice recognition, or a retinal scan.
A touch screen has a pressure-sensitive transparent panel. The computer receives instructions specific to the place on the screen that the user touches.
A scanner digitizes an image or document. The digitization of the image is stored as a file that can be displayed, printed, or altered.
Identify the names, purposes, and characteristics of output devices         
Here are some examples of output devices:
-          Monitors and projectors
-          Printers, scanners, and fax machines
-          Speakers and headphones
-          Monitors and Projectors
Monitors and projectors are primary output devices for a computer. There are different types of monitors, The most important difference between these monitor types is the technology used to create an image:
-          CRT   The cathode-ray tube (CRT) has three electron beams. Each beam directs colored phosphor on the screen that glows either red, blue, or green. Areas not struck by an electron beam do not glow.
-          LCD   Liquid crystal display is commonly used in flat panel monitors, laptops, and some projectors.
-          DLP   Digital light processing is another technology used in projectors.
Pixels are the tiny dots that comprise a screen. Each pixel consists of red, green, and blue.
Dot pitch   Dot pitch is the distance between pixels on the screen. A lower dot pitch number produces a better image.
Contrast ratio   The contrast ratio is a measurement of the difference in intensity of light between the brightest point (white) and the darkest point (black).
Refresh rate   The refresh rate is how often per second the image is rebuilt.
Interlace/Non-Interlace   Interlaced monitors create the image by scanning the screen two times. The first scan covers the odd lines, top to bottom, and the second scan covers the even lines.
Horizontal Vertical Colors (HVC)   The number of pixels in a line is the horizontal resolution. The number of lines in a screen is the vertical resolution.
Aspect ratio   Aspect ratio is the horizontal to vertical measurement of the viewing area of a monitor.
Native resolution   Native resolution is the number of pixels that a monitor has.
pixels. Native mode is when the image sent to the monitor matches the native resolution of the monitor.
Here are some common monitor settings:
       -          Brightness   Intensity of the image
       -          Contrast   Ratio of light to dark
       -          Position   Vertical and horizontal location of image on the screen
       -          Reset   Returns the monitor settings to factory settings
-          Adding additional monitors increases the number of windows that are visible on the desktop.
All-in-One Printer
Printers are output devices that create hard copies of computer files.
Speakers and Headphones
Speakers and headphones are output devices for audio signals.
Explain system resources and their purposes
There are three common system resources:
-          Interrupt Requests (IRQ)
-          Input/Output (I/O) Port Addresses
-          Direct Memory Access (DMA)
-          Interrupt Requests

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  Ø THE INTERNET AND STANDAR

The Internet is a worldwide, publicly accessible network of networks.
The way people interact, share information, and even do business is changing to keep up with the continuous evolution of this global network. The Internet is creating a wider audience and consumer base for whatever message, product, or service can be delivered.
Some of the business uses of the Internet include:

 ü  E-Commerce
 ü  Communications
 ü  Collaboration and training


  Ø ISP AND SERVICE

An ISP is a company or organization through which a subscriber obtains Internet access.

ISP may also offer other services to customers, including:

 ü  Equipment co-location
 A business may opt to have some or all internal network equipment physically located on the ISP            premises.

 ü  Web hosting
The ISP provides the server and application software for storing web pages and web content for the business website.

 ü  FTP
The ISP provides the server and application software for the FTP site of a business.

 ü  Applications and media hosting
The ISP provides the server and software to allow a business to provide streaming media such as music, video, or applications such as online databases.

 ü  Voice over IP
A business can save on long distance telephone charges, especially for internal calls between geographically distant offices, by using Voice over IP (VoIP).

 ü  Technical support
Many businesses do not have the in-house technical expertise to manage large internal networks. Some ISPs provide technical support and consulting services for an additional fee.

 ü  Point of Presence (POP)

 ü  A business has the option of connecting to the ISP through POP, using a variety of access technologies.


  Ø  DELIVERING INTERNET SERVICE TO AND USER

The main connection methods used by home and small business users are:

 ü  Dialup access
Dialup access is an inexpensive option that uses any phone line and a modem. To connect to the ISP, a user calls the ISP access phone number. Dialup is the slowest connection option, and is typically used by mobile workers and in areas where higher speed connection options are not available.

 ü  DSL
Digital subscriber line, or DSL, is more expensive than dialup, but provides a faster connection. DSL also uses telephone lines, but unlike dialup access, DSL provides a continuous connection to the Internet. This connection option uses a special high-speed modem that separates the DSL signal from the telephone signal and provides an Ethernet connection to a host computer or LAN.

 ü  Cable modem
A cable modem is a connection option offered by cable television service providers. The Internet signal is carried on the same coaxial cable that delivers cable television to homes and businesses. A special cable modem separates the Internet signal from the other signals carried on the cable and provides an Ethernet connection to a host computer or LAN.

 ü  Satellite
Satellite connection is an option offered by satellite service providers. The user's computer connects through Ethernet to a satellite modem that transmits radio signals to the nearest Point of Presence, or POP, within the satellite network.

        · BANDWIDTH

Bandwidth is measured in bits per second (bps). Higher bandwidth speeds are measured in kilobits per second (kbps), megabits per second (Mbps), or gigabits per second (Gbps).

There are three main types of high-bandwidth connection options that are used by businesses:

 ü  T1 connections transmit data up to 1.544 Mbps.

 ü  T3 connections transmit data up to 45 Mbps.

 ü Metro Ethernet offers a wide range of high-bandwidth options, including Gbps links.  Metro Ethernet allows  the transfer of large amounts of data faster and less expensively than other high-bandwidth connection options.


  Ø INTERNET HIERARCHICAL

The Internet has a hierarchical structure. At the top of this hierarchy are the ISP organizations. The ISP POPs connect to an Internet Exchange Point (IXP). In some countries, this is called a Network Access Point (NAP). An IXP or NAP is where multiple ISPs join together to gain access to each other's networks and exchange information.

The Internet backbone is like an information super highway that provides high-speed data links to interconnect the POPs and IXPs in major metropolitan areas around the world. The primary medium that connects the Internet backbone is fiber-optic cable.

ISP level access to the Internet backbone:

 ü  Tier 1 ISPs are the top of the hierarchy. Tier 1 ISPs are huge organizations that connect directly with each other through private peering, physically joining their individual network backbones together to create the global Internet backbone.

 ü  Tier 2 ISPs are the next tier in terms of backbone access. Tier 2 ISPs can also be very large, even extending across several countries, but very few have networks that span entire continents or between continents.

 ü  Tier 3 ISPs are the farthest away from the backbone. Tier 3 ISPs are generally found in major cities and provide customers local access to the Internet. Tier 3 ISPs pay Tier 1 and 2 ISPs for access to the global Internet and Internet services.


  Ø USING TOOLS TO MAP THE INTERNET

The ping command sends an ICMP (Internet Control Message Protocol) echo request packet to the destination address and then waits for an echo reply packet to return from that host. ICMP is an Internet protocol that is used to verify communications.

To use the ping command, enter the following command at the Cisco command line interface (CLI) router prompt or at the Windows command prompt:

ping <ip address>

where <ip address> is the IP address of the destination device.


  Ø ISP REQUIREMENT

Some of the devices required to provide services include:

 ü  Access devices that enable end users to connect to the ISP, such as a DSL Access Multiplexer (DSLAM) for DSL connections, a Cable Modem Termination System (CMTS) for cable connections, modems for dialup connections, or wireless bridging equipment for wireless access.

 ü  Border gateway routers to enable the ISP to connect and transfer data to other ISPs, IXPs, or large business enterprise customers.

 ü  Servers for such things as email, network address assignment, web space, FTP hosting, and multimedia hosting.

 ü  Power conditioning equipment with substantial battery backup to maintain continuity if the main power grid fails.

 ü  High capacity air conditioning units to maintain controlled temperatures.
Loss of customers directly translates to loss of income for an ISP. For this reason, it is important that the ISP provides a reliable and scalable network.

Scalability is the capacity of a network to allow for future change and growth. Scalable networks can expand quickly to support new users and applications without affecting the performance of the service being delivered to existing users.

The most scalable devices are those that are modular and provide expansion slots for adding modules. Different modules can have different numbers of ports. In the case of a chassis router, some modules also offer different interface options, allowing for different connection options on the same chassis.

It is important for ISPs to provide a reliable and scalable network.
Scalability is the capacity of a network to allow for future change and growth. Scalable networks can expand quickly to support new users and applications without affecting the performance of the service being delivered to existing users.

The most scalable devices are those that are modular and provide expansion slots for adding modules. Different modules can have different numbers of ports. In the case of a chassis router, some modules also offer different interface options, allowing for different connection options on the same chassis.

  Ø ROLES AND RESPONSILIBITIES WITHIN AN ISP

Each of the network support service teams have their own roles and responsibilities:

 ü  Customer Service receives the order from the customer and ensures that the specified requirements of the customer are accurately entered into the order tracking database.

 ü  Planning and Provisioning determines whether the new customer has existing network hardware and circuits and if new circuits need to be installed.

 ü  The On-site Installation is advised of which circuits and equipment to use and then installs them at the customer site.

 ü  The Network Operations Center (NOC) monitors and tests the new connection and ensures that it is performing properly.

 ü  The Help Desk is notified by the NOC when the circuit is ready for operation and then contacts the customer to guide them through the process of setting up passwords and other necessary account information.




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