22081633-IT-Essentials-Chapter-1-15-Notes

Chapter 1 Notes Introduction A firewire port can support up to 63 Firewire Devices USB: Universal Serial Bus A USB port can support up to 127 USB Devices. USB 2.0 has a maximum Data Speed of 480 Mbps IEEE 1394a Standard has a Maximum Data Rate of 400 Mbps CEPIS: Council of European Professional Informatics Societies CompTIA: Computing Technology Industry Association A computer system consists of hardware and software components. Hardware is the physical equipment such as the case, storage drives, keyboards, monitors, cables, speakers, and printers. Software includes the operating system and programs. Operating System (OS): instructs the computer how to operate. Programs/Applications: Programs vary widely depending on the type of information that will be accessed or generated. (i.e. Instructions for balancing a checkbook are very different from instructions for simulating a virtual reality world on the Internet.) Computer Case: provides protection and support for the internal components of the computer. (AKA: Computer chassis, Cabinet, Tower, Box, and Housing) A/C power: Alternating Current (Found in wall plugs): the movement (or flow) of electric charge periodically reverses direction. D/C power: Direct Current: is the unidirectional flow of electric charge. Electricity and Ohm's Law these are the four basic units of electricity: Voltage: a measure of the force required to push electrons through a circuit. Measured in volts (V). A computer power supply usually produces several different voltages. Current: a measure of the amount of electrons going through a circuit. Measured in amperes, or amps (A). Computer power supplies deliver different amperages for each output voltage. Power: 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. The measurement is called watts (W). Computer power supplies are rated in watts. Resistance: the opposition to the flow of current in a circuit. Measured in ohms. Lower resistance allows more current, and therefore more power, to flow through a circuit. A good fuse will have low resistance or a measurement of almost 0 ohms. Power Supply: converts alternating-current (AC) power from the wall socket into direct-current (DC) power. Form Factor: The size and layout of a case. 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 and Available space. Connectors Most connectors today are keyed connectors. Keyed connectors are designed to be inserted in only one direction. Each part of the connector has a colored wire with a different voltage running through it, as seen in Figure 2. Different connectors are used to connect specific components and various locations on the motherboard: Molex: A keyed connector used to connect to an optical drive or a hard drive. Berg: A keyed connector used to connect to a floppy drive. (A Berg connector is smaller than a Molex connector. 20-pin or 24-pin: used to connect to the motherboard. The 24-pin slotted connector has two rows of 12-pins each. The 20-pin slotted connector has two rows of 10-pins each. 4-pin to 8-pin auxiliary power: two rows of two to four pins and supplies power to all areas of the motherboard and are the same shape as the main power connector, but smaller. Older standard power supplies used two connectors called P8 and P9 to connect to the motherboard. P8 and P9 were un-keyed connectors. They could be installed backwards, potentially damaging the motherboard or power supply. The installation required that the connectors were lined up with the black wires together in the middle. Motherboard Motherboard: the main printed circuit board and contains the buses, or electrical pathways, found in a computer. (AKA system board, the backplane, or the main board) Bus: allows data to travel between the various components that comprise a computer. The motherboard accommodates the central processing unit (CPU), RAM, expansion slots, heat sink/fan assembly, BIOS chip, chip set, and the embedded wires that interconnect the motherboard components. Sockets, internal and external connectors, and various ports are also placed on the motherboard. Chip Set: various integrated circuits attached to the motherboard that control how system hardware interacts with the CPU and motherboard. The chip set of a motherboard allows the CPU to communicate and interact with the other components of the computer, and to exchange data with system memory, or RAM, hard disk drives, video cards, and other output devices. The chip set establishes how much memory can be added to a motherboard. The chip set also determines the type of connectors on the motherboard. Most chip sets are divided into two distinct components, Northbridge and Southbridge. Northbridge: controls access to the RAM, video card, and the speeds at which the CPU can communicate with them. The video card is sometimes integrated into the Northbridge. Southbridge: in most cases, allows the CPU to communicate with the hard drives, sound card, USB ports, and other I/O ports. CPU: Central Processing Unit: considered the brain of the computer. CPU Socket/Slot: the connector that interfaces between the motherboard and the processor itself. PGA: pin grid array ZIF: zero insertion force 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. Hyper threading: the CPU has multiple pieces of code being executed simultaneously on each pipeline. To an operating system, a single CPU with hyper threading appears to be two CPUs. MHz: Megahertz GHz: Gigahertz FSB: Front Side Bus Current processors have a 32-bit or a 64-bit processor data bus. Over clocking: a technique used to make a processor work at a faster speed than normal. Over clocking is not reliable can result in damaging the CPU. MMX: a set of multimedia instructions built into Intel processors. Enabled microprocessors can handle many common multimedia operations that are handled by a separate sound or video card. Only software especially written to call MMX instructions can take advantage of the instruction set.Many CPUs are capable of processing multiple instructions concurrently: Single Core CPU – One core inside a single CPU chip 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 chip in which both cores can process information at the same time. GPU: graphics-processing unit RAM: Random Access Memory DRAM: Dynamic RAM: Dynamic RAM is a memory chip that is used as main memory. DRAM must be constantly refreshed with pulses of electricity in order to maintain the data stored within the chip. SRAM: Static RAM: Static RAM is a memory chip that is used as cache memory. SRAM is much faster than DRAM and does not have to be refreshed as often. FPM Memory: Fast Page Mode DRAM is memory that supports paging. Paging enables faster access to the data than regular DRAM. Most 486 & Pentium systems from ’95 and earlier use FPM memory. EDO Memory: Extended Data Out RAM is memory that overlaps the consecutive data accesses. This speeds up the access time to retrieve data from memory, because the CPU does not have to wait for one data access cycle to end before another data access cycle begins. SDRAM: Synchronous DRAM is DRAM that operates in synchronization with the memory bus. The memory bus is the data path between the CPU and the main memory. DDR SDRAM: Double Data Rate SDRAM is memory that xfers data twice as fast as SDRAM. DDR SDRAM increases performance by xferring data twice per cycle. DDR2 SDRAM: Double Data Rate 2 SDRAM is a faster than DDR-SDRAM memory. DDR2 improves performance over DDR by decreasing noise and crosstalk between the signal wires. RDRAM: RAM Bus DRAM is a memory chip that was developed to communicate at very high rates of speed. RDRAM chips are not commonly used. ROM: Read-only memory chip: Information written when manufactured and cannot be erased. PROM: Programmable read-only memory: Information written when manufactured and cannot be erased or rewrittten EPROM: Erasable programmable read-only memory: Information written AFTER chip is manufactured and can be erased with exposure to a UV light. Special equipment required. EEPROM: Electrically erasable programmable read-only memory (AKA Flash ROM): Information is written AFTER manufactured and can be erased and re-written without removal from computer. DIP: dual inline package: individual memory chip: dual rows of pins used to attach to computer. SIMM: Single Inline Memory Module: Small circuit board that holds several memory chips: 30-pin and 72-pin configurations. DIMM: Dual Inline memory module: circuit board that holds SDRAM, DDR SDRAM and DDR2 SDRAM chips. There are 168-pin SDRAM DIMMs, 184-pin DDR DIMMs, and 240-pin DDR2 DIMMs. RIMM: RAM Bus Inline Memory Module: a circuit board that holds RDRAM chip. RIMM typically has a 184-pin configuration. L1 Cache: is internal cache and is integrated into the CPU. L2 Cache: is external cache and was originally mounted on the motherboard near the CPU and is now integrated into the CPU. L3 Cache: is used on some high-end workstations and server CPUs. Nonparity memory: does not check for errors in memory. Parity Memory: contains 8 bits for data and 1 bit for error checking. Parity Bit: The 1 bit that does check for errors within the Parity Memory. ECC Memory: Error Correction Code: can detect multiple bit errors in memory and correct single bit errors in memory. Adapter cards are used to expand and customize the capability of the computer: 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 Modem adapter – Connects a computer to the Internet using a phone line CSI adapter – Connects SCSI devices, such as hard drives or tape drives, to a computer RAID adapter – Connects multiple hard drives to a computer to provide redundancy and to improve performance USB port – Connects a computer to peripheral devices Parallel port – Connects a computer to peripheral devices Serial port – Connects a computer to peripheral devices A riser card was used in computer systems with the LPX form factor to allow adapter cards to be installed horizontally. The riser card was mainly used in slim-line desktop computers. ISA: Industry Standard Architecture: 8 or 16-bit expansion slot. This older technology is seldom used. EISA: Extended Industry Standard Architecture: 32-bit expansion slot. This older technology is seldom used. MCA: Micro channel Architecture: an IBM-proprietary 32-bit expansion slot. This older technology is seldom used. PCI: Peripheral Component Interconnect: 32 or 64-bit expansion slot currently used in most computers. AGP: Advanced Graphics Port: 32-bit expansion slot designed for video adapters. PCI-Express (PCI-E): a serial bus expansion slot. Software that is compatible has x1, x4, x8 and x16 slots. A storage drive reads or writes information to magnetic or optical storage media. The drive can be used to store data permanently or to retrieve information from a media disk. Storage drives can be installed inside the computer case, such as a hard drive. For portability, some storage drives can connect to the computer using a USB port, a FireWire port, or an SCSI port. These portable storage drives are sometimes referred to as removable drives and can be used on multiple computers. Here are some common types of storage drives: Floppy Drive: a storage device that uses removable 3.5-inch floppy disks that can store 720 KB or 1.44 MB of data. In a computer, the floppy drive is usually configured as the A: drive. The floppy drive can be used to boot the computer if it contains a bootable floppy disk. A 5.25-inch floppy drive is older technology and is seldom used. Hard Drive: a magnetic storage device that is installed inside the computer. The hard drive is used as permanent storage for data. In a computer, the hard drive is usually configured as the C: drive and contains the operating system and applications. The hard drive is usually configured as the first drive in the boot sequence. The storage capacity of a hard drive is measured in billions of bytes, or gigabytes (GB). The speed of a hard drive is measured in revolutions per minute (RPM). Multiple hard drives can be added to increase storage capacity. Optical Drive An optical drive is a storage device that uses lasers to read data on the optical media. There are two types of optical drives: CD: Compact disc DVD: Digital Versatile Disc CD and DVD media can be pre-recorded (read-only), recordable (write once), or re-recordable (read and write multiple times). CDs have a data storage capacity of approximately 700 MB. DVDs have a data storage capacity of approximately 8.5 GB on one side of the disc. 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 once. CD-RW – CD-rewritable media that can be recorded, erased, and re-recorded. DVDRRO – DVD read-only memory media that is pre-recorded. DVDRRA – DVD-random access memory media that can be recorded, erased, and re-recorded. DVD+/-R – DVD-recordable media that can be recorded once. DVD+/-RW – DVD-rewritable media that can be recorded, erased, and re-recorded. Flash Drive (AKA a thumb drive): is a removable storage device that connects to a USB port. A flash drive uses a type of memory that requires no power to maintain the data. These drives can be accessed by the operating system in the same way other types of drives are accessed. Types of Drive Interfaces Hard drives and optical drives are manufactured with different interfaces that are used to connect the drive to the computer. To install a storage drive in a computer, the connection interface on the drive must be the same as the controller on the motherboard. Here are some common drive interfaces: IDE – Integrated Drive Electronics, also called Advanced Technology Attachment (ATA) is an early drive controller interface that connects computers and hard disk drives. An IDE interface uses a 40-pin connector. EIDE – Enhanced Integrated Drive Electronics, also called ATA-2, is an updated version of the IDE drive controller interface. EIDE supports hard drives larger than 512 MB, enables Direct Memory Access (DMA) for speed, and uses the AT Attachment Packet Interface (ATAPI) to accommodate optical drives and tape drives on the EIDE bus. An EIDE interface uses a 40-pin connector. PATA – Parallel ATA refers to the parallel version of the ATA drive controller interface. SATA – Serial ATA refers to the serial version of the ATA drive controller interface. A SATA interface uses a 7-pin connector. SCSI – Small Computer System Interface is a drive controller interface that can connect up to 15 drives. SCSI can connect both internal and external drives. An SCSI interface uses a 50-pin, 68-pin, or 80-pin connector. Data cables connect drives to the drive controller, which is located on an adapter card or on the motherboard. Here are some common types of data cables: Floppy disk drive (FDD) data cable – Data cable has up to two 34-pin drive connectors and one 34-pin connector for the drive controller. PATA (IDE/EIDE) 40-conductor data cable -Originally, the IDE interface supported two devices on a single controller. With the introduction of Extended IDE, two controllers capable of supporting two devices each were introduced. 40-pin connectors are used on 40-conductor ribbon cable. The cable has two connectors for the drives and a third for the controller. PATA (EIDE) 80-conductor cable -As the data rates available over the EIDE interface increased, the chances of corruption of the data being transmitted increased. The use of 80-conductor cable was introduced for devices transmitting at 33.3MBps and over, allowing for a more reliable balanced data transmission. The connectors are still of the 40-pin variety. SATA data cable – Serial ATA data cable has seven conductors, one keyed connector for the drive, and one keyed connector the drive controller. SCSI data cable – There are three types of SCSI data cables. A narrow SCSI data cable has 50-conductors, up to seven 50-pin connectors for drives, and one 50-pin connector for the drive controller, also called the host adapter. A wide SCSI data cable has 68-conductors, up to fifteen 68-pin connectors for drives, and one 68-pin connector for the host adapter. An Alt-4 SCSI data cable has 80-conductors, up to "15" 80-pin connectors for drives, and one 80-pin connector for the host adapter. 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 and Video Serial Ports and Cables a serial port can be either a DB-9 or a DB-25 male connector. Serial ports transmit one bit of data at a time. To connect a serial device, such as a modem or printer, a serial cable must be used. A serial cable has a maximum length of 50 feet (15.2 m). USB Ports and Cables: is a standard interface that connects peripheral devices to a computer. It was originally designed to replace serial and parallel connections. Hot-Swappable: users can connect and disconnect the devices while the computer is powered on. USB connections can be found on computers, cameras, printers, scanners, storage devices, and many other electronic devices. A USB hub is used to connect multiple USB devices. A single USB port in a computer can support up to 127 separate devices with the use of multiple USB hubs. Some devices can also be powered through the USB port, eliminating the need for an external power source. USB 1.1: allowed transmission rates of up to 12 Mbps in full-speed mode and 1.5 Mbps in low speed mode. USB 2.0: allows transmission speeds up to 480 Mbps. USB devices can only transfer data up to the maximum speed allowed by the specific port. FireWire Ports and Cables: a high-speed, hot-swappable interface that connects peripheral devices to a computer. A single FireWire port in a computer can support up to 63 devices. Some devices can also be powered through the FireWire port, eliminating the need for an external power source. FireWire uses the IEEE 1394 standard (AKA i.Link.)The IEEE 1394a standard supports data rates up to 400 Mbps and cable lengths up to 15 feet (4.5 m). This standard uses a 6-pin connector or a 4-pin connector. The IEEE 1394b standard allows for a greater range of connections, including CAT5 UTP and optical fiber. Depending on the media used, data rates are supported up to 3.2 Gbps over a 100m distance. Figure 3 shows FireWire cables with connectors. Parallel Ports and Cables: A parallel port on a computer is a standard Type A DB-25 female connector. The parallel connector on a printer is a standard Type B 36-pin Centronics connector. Some newer printers may use a Type C high-density 36-pin connector. Parallel ports can transmit 8 bits of data at one time and use the IEEE 1284 standard. To connect a parallel device, such as a printer, a parallel cable must be used. A parallel cable, as shown in Figure 4, has a maximum length of 15 feet (4.5 m). 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. If a single SCSI device is connected to an SCSI port, the cable can be up to 80 feet (24.4 m) in length. If multiple SCSI devices are connected to an SCSI port, the cable can be up to 40 (12.2 m) feet in length. An SCSI port on a computer can be one of three different types, (i.e. 50-pin connector, 68-pin connector and an 80-pin connector) NOTE: SCSI devices must be terminated at the endpoints of the SCSI chain. CAUTION: Some SCSI connectors resemble parallel connectors. Be careful not to connect the cable to the wrong port. The voltage used in the SCSI format may damage the parallel interface. SCSI connectors should be clearly labeled. Network Ports and Cables: A network port, also known as an RJ-45 port, connects a computer to a network. The connection speed depends on the type of network port. Standard Ethernet can transmit up to 10 Mbps, Fast Ethernet can transmit up to 100 Mbps, and Gigabit Ethernet can transmit up to 1000 Mbps. The maximum length of network cable is 328 feet (100 m). A network connector is shown in Figure 6. PS/2 Ports: connects a keyboard or a mouse to a computer. The PS/2 port is a 6-pin mini-DIN female connector. The connectors for the keyboard and mouse are often colored differently. If the ports are not color-coded, look for a small figure of a mouse or keyboard next to each port. Audio Ports: connects audio devices to the computer. The following audio ports are commonly used: Line In – Connects to an external source, such as a stereo system Microphone – Connects to a microphone Line Out – Connects to speakers or headphones Game port/MIDI – Connects to a joystick or MIDI-interfaced device Video Ports and Connectors: connects a monitor cable to a computer. 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 a compressed 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. SViide – 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. Input Device: is used to enter data or instructions into a computer. (I.e. Mouse, keyboard, Digital camera or digital video camera, Biometric authentication device, Touch screen and Scanner.) GUI: graphical user interface Biometric Identification: makes use of features that are unique to an individual user, such as fingerprints, voice recognition, or a retinal scan. When combined with ordinary usernames, biometrics guarantees that the authorized person is accessing the data. Touch Screen: has a pressure-sensitive transparent panel. The computer receives instructions specific to the place on the screen that the user touches. Scanner: machine that digitizes an image or document. The digitization of the image is stored as a file that can be displayed, printed, or altered. Bar Code Reader: is a type of scanner that reads Universal Product Code (UPC) bar codes. It is widely used for pricing and inventory information. An output device is used to present information to the user from a computer. (I.e. Monitors, projectors, Printers, scanners, 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: Cathode-ray tube monitor: is the most common monitor type. LCD: Liquid crystal display: is commonly used in laptops and some projectors. LCD comes in two forms. Active matrix: is sometimes called thin film transistor (TFT). Passive matrix: does not provide the same level of image control. DLP: Digital light processing: is another technology used in projectors. DMD: Digital Micro mirror Device. Monitor resolution refers to the level of image detail that can be reproduced. Figure 2 is a chart of common monitor resolutions. Higher resolution settings produce better image quality. There are several factors involved in monitor resolution: Pixels: the tiny dots that comprise a screen. Each pixel consists of red, green, and blue. Dot Pitch: the distance between pixels on the screen. A lower dot pitch number produces a better image. Refresh Rate: how often per second the image is rebuilt. A higher refresh rate produces a better image and reduces the level of flicker. Interlace: 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. Non-Interlace: Non-interlaced monitors create the image by scanning the screen, one line at a time from top to bottom. Most CRT monitors today are non-interlaced. HVC: Horizontal Vertical Colors: The number of pixels in a line is the horizontal resolution. The number of lines in a screen is the vertical resolution. The number of colors that can be reproduced is the color resolution. Aspect Ratio: the horizontal to vertical measurement of the viewing area of a monitor. Monitors have controls for adjusting the quality of the image. 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 Printers, Scanners, and Fax Machines: that creates hard copies of computer files. Some printers specialize in particular applications, such as printing color photographs. Other all-in-one type printers are designed to provide multiple services such as printing, fax, and copier functions. Speakers and Headphones: are output devices for audio signals. Most computers have audio support either integrated into the motherboard or on an adapter card. Audio support includes ports that allow input and output of audio signals. The audio card has an amplifier to power headphones and external speakers. IRQ: Interrupt Requests: used by computer components to request information from the CPU. Older computers only had eight IRQs to assign to devices. Newer computers have 16 IRQs, which are numbered 0 to 15. IRQ conflicts can cause components to stop functioning and even cause the computer to crash. Today, most IRQ numbers are assigned automatically with plug and play (PnP) operating systems and the implementation of PCI slots, USB ports, and FireWire ports. Input/Output (I/O) Port Addresses: are used to communicate between devices and software and is used to send and receive data for a component. There are 65,535 I/O ports in a computer, and they are referenced by a hexadecimal address in the range of 0000h to FFFFh. DMA: Direct Memory Access: are used by high-speed devices to communicate directly with main memory. These channels allow the device to bypass interaction with the CPU and directly store and retrieve information from memory. Only certain devices can be assigned a DMA channel, such as SCSI host adapters and sound cards. Older computers only had four DMA channels to assign to components. Newer computers have eight DMA channels that are numbered 0 to 7, as shown in Figure 3. Chapter 2 Notes ESD: Electric Static Discharge: Static electricity is the buildup of an electric charge resting on a surface. This buildup may zap a component and cause damage. ESD Protection Recommendations: Keep all components in antistatic bags until you are ready to install them. Use grounded mats on workbenches. Use grounded floor mats in work areas. Use antistatic wrist straps when working on computers. Climate Climate affects computer equipment in a variety of ways: If the environment temperature is too high, equipment can overheat. If the humidity level is too low, the chance of ESD increases. If the humidity level is too high, equipment can suffer from moisture damage. MSDS: Material Safety and Data Sheet: a fact sheet that summarizes information about material identification, including hazardous ingredients that can affect personal health, fire hazards, and first aid requirements. Proper Disposal of Batteries, Monitors or CRTs, Toner Kits, Cartridges, Developers, Chemical Solvents and Aerosol Cans: Recycling should be a standard practice for a technician. And a technician should always use disposal procedures that comply with local and federal environmental regulations. A technician MUST make sure that they are familiar with the necessary tools and software. A technician must document all repairs and computer problems. If anything for further reference or for other tech’s. ESD Tools: antistatic wrist strap: protects computer equipment when grounded to a computer chassis antistatic mat: protects computer equipment by preventing static electricity from accumulating on the hardware or on the technician Hand Tools: Flathead Screwdriver, Phillips head Screwdriver, Torx Screwdriver, Hex Driver, Needlenoos Pliers, Wire Cutters, Tweezers, Part Retriever and flashlight. Cleaning Tools: Soft Cloth: used to clean different computer components without scratching or leaving debris. Compressed Air: Used to blow away dust and debris from different computer parts without touching the components. Cable Ties: used to bundle cables neatly inside and outside of a computer. Parts Organizer: used to hold various parts and prevents them from getting mixed together. Diagnostic Tools:Digital Multimeter: used to test the integrity of circuits and the quality of electricity in components. Loopback Adapter: Used to test the basic functionality of computer ports. Disk Management Tools Fdisk or Disk Management – used to create and delete partitions on a hard drive Format – used to prepare a hard drive to store information Scandisk or Chkdsk – used to check the integrity of files and folders on a hard drive by scanning the file system. They may also check the disk surface for physical errors Defrag – used to optimize space on a hard drive to allow faster access to programs and data Disk Cleanup – used to clear space on a hard drive by searching for files that can be safely deleted Disk Management – a system utility used to manage hard drives and partitions, which performs tasks such as initializing disks, creating partitions, and formatting partitions System File Checker (SFC) – a command-line utility that scans the operating system critical files and replaces any files that are corrupted Protection Software Tools Windows XP Security Center – allows you to check the status of essential security settings on the computer. Antivirus Program – protects a computer against virus attacks. Spyware Remover – protects against software that sends information about web surfing habits to an attacker. Spyware can be installed without the knowledge or consent of the user. Firewall – a program that runs continuously to protect against unauthorized communications to and from your computer. Personal Reference Tools Notes – Make notes as you go through the investigation and repair process. Refer to these notes to avoid repeating previous steps and to determine what steps to take next. Journal – Document the upgrades and repairs that you perform. History of repairs – Make a detailed list of problems and repairs, including the date, replacement parts, and customer information. The history allows a technician to determine what work has been performed on a computer in the past. Internet Reference Tools The Internet is an excellent source of information about specific hardware problems and possible solutions: Internet search engines, News groups, Manufacturer FAQs (Frequently Asked Questions), online computer manuals, online forums and chat, Technical websites Chapter 3 Notes What needs to be done before the installation of the motherboard. Heat Sink/Fan Assembly 1. Align the CPU so that the Connection 1 indicator is lined up with Pin 1 on the CPU socket. Doing this ensures that the orientation notches on the CPU are aligned with the orientation keys on the CPU socket. 2. Place the CPU gently into the socket. 3. Close the CPU load plate and secure it in place by closing the load lever and moving it under the load lever retention tab. 4. Apply a small amount of thermal compound to the CPU and spread it evenly. Follow the application instructions provided by the manufacturer. 5. Align the heat sink/fan assembly retainers with the holes on the motherboard. 6. Place the heat sink/fan assembly onto the CPU socket, being careful not to pinch the CPU fan wires. 7. Tighten the heat sink/fan assembly retainers to secure the assembly in place. 8. Connect the heat sink/fan assembly power cable to the header on the motherboard. RAM installation 1. Align the notches on the RAM module to the keys in the slot and press down until the side tabs click into place. 2. Make sure that the side tabs have locked the RAM module. Visually check for exposed contacts. Plastic and metal standoffs are used to mount the motherboard and to prevent it from touching the metal portions of the case. You should install only the standoffs that align with the holes in the motherboard. Motherboard installation: 1. Install standoffs in the computer case. 2. Align the I/O connectors on the back of the motherboard with the openings in the back of the case. 3. Align the screw holes of the motherboard with the standoffs. 4. Insert all of the motherboard screws. 5. Tighten all of the motherboard screws. Drives that are installed in internal bays are called internal drives. A hard disk drive (HDD) is an example of an internal drive. HDD installation: · Position the HDD so that it aligns with the 3.5-inch drive bay. · Insert the HDD into the drive bay so that the screw holes in the drive line up with the screw holes in the case. · Secure the HDD to the case using the proper screws. Drives, such as optical drives and floppy drives, are installed in drive bays that are accessed from the front of the case. Optical drives and floppy drives store data on removable media. Drives in external bays allow access to the media without opening the case. An optical drive is a storage device that reads and writes information to CDs and DVDs and uses a Molex power connector and a PATA data connector. Optical drive installation: 1. Position the optical drive so that it aligns with the 5.25-inch drive bay. 2. Insert the optical drive into the drive bay so that the optical drive screw holes align with the screw holes in the case. 3. Secure the optical drive to the case using the proper screws. A floppy disk drive (FDD) is a storage device that reads and writes information to a floppy disk and uses a Berg power connector and a floppy data connector. FDD installation: · Position the FDD so that it aligns with the 3.5-inch drive bay. · Insert the FDD into the drive bay so that the FDD screw holes align with the screw holes in the case. · Secure the FDD to the case using the proper screws. Adapter cards are installed to add functionality to a computer. A NIC enables a computer to connect to a network. NIC: Network Integration Card NIC installation: 1. Align the NIC to the appropriate expansion slot on the motherboard. 2. Press down gently on the NIC until the card is fully seated. 3. Secure the NIC PC mounting bracket to the case with the appropriate screw. Wireless NIC installation: 1. Align the wireless NIC to the appropriate expansion slot on the motherboard. 2. Press down gently on the wireless NIC until the card is fully seated. 3. Secure the wireless NIC PC mounting bracket to the case with the appropriate screw. A video adapter card is the interface between a computer and a display monitor. An upgraded video adapter card can provide better graphic capabilities for games and graphic programs. Video adapter cards use PCI, AGP, and PCIe expansion slots on the motherboard. Video adapter card installation:1. Align the video adapter card to the appropriate expansion slot on the motherboard. 2. Press down gently on the video adapter card until the card is fully seated. 3. Secure the video adapter card PC mounting bracket to the case with the appropriate screw. Power cables are used to distribute electricity from the power supply to the motherboard and other components. Data cables transmit data between the motherboard and storage devices, such as hard drives. Additional cables connect the buttons and link lights on the front of the computer case to the motherboard. Motherboard Power Connections Motherboard power cable installation: 1. Align the 20-pin ATX power connector to the socket on the motherboard. 2. Gently press down on the connector until the clip clicks into place. 3. Align the 4-pin AUX power connector to the socket on the motherboard. 4. Gently press down on the connector until the clip clicks into place. SATA Power Connectors SATA power connectors use a 15-pin connector. SATA power connectors are used to connect to hard disk drives, optical drives, or any devices that have a SATA power socket. Molex Power Connectors Hard disk drives and optical drives that do not have SATA power sockets use a Molex power connector. Berg Power Connectors The 4-pin Berg power connector supplies power to a floppy drive. Follow these steps for power connector installation: 1. Plug the SATA power connector into the HDD. [Figure 3] 2. Plug the Molex power connector into the optical drive. [Figure 4] 3. Plug the 4-pin Berg power connector into the FDD. [Figure 5] 4. Connect the 3-pin fan power connector into the appropriate fan header on the motherboard, according to the motherboard manual. [Figure 6] 5. Plug the additional cables from the case into the appropriate connectors according to the motherboard manual. PATA Data Cables sometimes called a ribbon cable because it is wide and flat. The cable can have either 40 or 80 conductors, but usually has three 40-pin connectors. One connects to the motherboard. The other two connectors connect to drives. The master drive will connect to the end connector. The slave drive will connect to the middle connector. SATA Data Cables The SATA data cable has a 7-pin connector. One end is connected to the motherboard and the other is connected to any drive that has a SATA data connector. Floppy Data Cables the data cable has a 34-pin connector. Like the PATA data cable, the floppy drive cable has a stripe to denote the location of pin 1. A floppy drive cable usually has three 34-pin connectors. One connector at the end of the cable connects to the motherboard and the other(s) connect to drives. All FDD cables have a twist in the middle of the cable, which is usually a good sign of what the connector goes to. Data cable installation: 1. Plug the motherboard end of the PATA cable into the motherboard socket. 2. Plug the connector at the far end of the PATA cable into the optical drive. 3. Plug one end of the SATA cable into the motherboard socket. 4. Plug the other end of the SATA cable into the HDD. 5. Plug the motherboard end of the FDD cable into the motherboard socket. 6. Plug the connector at the far end of the FDD cable into the floppy drive. Now that all the internal components have been installed and connected to the motherboard and power supply, the side panels are re-attached to the computer case. Once the cover is in place, make sure that it is secured at all screw locations. Some computer cases use screws that are inserted with a screwdriver. Other cases have knob-type screws that can be tightened by hand. If you are unsure about how to remove or replace the computer case, refer to the documentation or website of the manufacturer for more information. Chapter 4 Notes Preventive maintenance: prevent failure of parts, materials, and systems by ensuring that they are in good working order. Troubleshooting: a systematic approach to locating the cause of, or, a fault in a computer system. Preventive maintenance Hardware Check the condition of cables, components, and peripherals. Clean components in order to reduce the likelihood of overheating. Repair or replace any components that show signs of abuse or excess wear. Software Verify that installed software is current. Follow the policies when installing security updates, operating system updates, and program updates. Benefits be proactive in computer equipment maintenance and data protection. By performing regular maintenance routines, you can reduce potential hardware and software problems. Doing this will reduce computer down time and repair costs. Troubleshooting Backup Data A backup is a copy of the data on a computer hard drive that is saved to media such as a CD or DVD. If you are unsure that a backup has been done, do not attempt any troubleshooting activities until you check with the customer. Here is a list of items to verify with the customer about data backups: 1. Date of the last backup 2. Contents of the backup 3. Data integrity of the backup 4. Availability of all backup media for a data restore If the customer does not have a current backup and you are not able to create one, you should ask the customer to sign a liability release form. A liability release form should contain at least the following information: 1. Permission to work on the computer without a current backup available 2. Release from liability if data is lost or corrupted 3. Description of the work to be performed Conversation EtiquetteGather Data Get the customer information, name, address, and company and phone number. Find out the system information, such as: make and model, Operating System, Network Environment and connection type. When talking to the customer follow these guidelines: · Ask direct questions to gather information. · Do not use technical terms when talking to customers. · Do not talk down to the customer. · Do not insult the customer. · Do not accuse the customer of causing the problem. By communicating effectively, you will be able to determine the most relevant information about the problem from the customer. Open-Ended Questions Open-ended questions are used to obtain general information. Open-ended questions allow customers to explain the details of the problem in their own words. Closed-Ended Questions Based on the information from the customer, you can proceed with closed-ended questions. Closed-ended questions generally require a "yes" or "no" answer. These questions are intended to get the most relevant information in the shortest time possible. The information obtained from the customer should be documented in the work order and in the repair journal. Write down anything that you think may be important for you or another technician. Often, the small details can lead to the solution of a difficult or complicated problem. The second step in the troubleshooting process is to verify the obvious issues. Obvious Issues · Loose external cable connections · Incorrect boot order in BIOS · Non-bootable disk in the FDD · Power switch for an outlet is turned off · Surge protector is turned off · Device is powered off The next step in the troubleshooting process is to try quick solutions first. Obvious issues and quick solutions sometimes overlap each other and can be used together to repair the problem. Quick Solutions · Check that all cables are connected to the proper locations · Remove and reconnect cables · Reboot the computer or network device · Log in as a different user or administrator · Check the computer for the latest OS patches and updates Gather data from the computer · Error Messages · Beep Sequences · LEDs · POST Event Viewer when system, user, or software errors occur on a computer, the Event Viewer is updated with information about the errors. · What problem occurred · The date and time of the problem · The severity of the problem · The source of the problem · Event ID number · Which user was logged in when the problem occurred Device Manager: displays all of the devices that are configured on a computer. Any device that the operating system determines to be acting incorrectly will be flagged with an error icon. A yellow circle with an exclamation point ("!"). If a device is disabled, it will be flagged with a red circle and an "X". A yellow question mark "?" indicates that the hardware is not functioning properly because the system does not know what driver to install for the hardware. Beep Codes Each BIOS manufacturer has a unique beep sequence for hardware failures. When troubleshooting, power on the computer and listen. As the system proceeds through the POST, most computers will emit one beep to indicate that the system is booting properly. If there is an error, you may hear multiple beeps. Document the sequence and research the code to determine the specific hardware failure. BIOS Information If the computer boots and stops after the POST, you should investigate the BIOS settings to determine where to find the problem. A device may not be detected or configured properly. Refer to the motherboard manual to make sure that the BIOS settings are accurate. Diagnostic Tools Conduct research to determine what software is available to help diagnose and solve problems. There are many programs available that can help you troubleshoot hardware. Often, manufacturers of system hardware provide diagnostic tools of their own. A hard drive manufacturer, for instance, may provide a tool that can be used to boot the computer and diagnose problems with the hard drive when it will not boot Windows. Evaluate the problem and research possible solutions · Problem Solving Experience · Other Tech’s · Internet Search · Newsgroups · Manufacturer FAQs · Computer Manuals · Device Manuals · Online Forums · Technical Websites Close with the Customer · Discuss the solution taken · Have customer verify: Problem Solved · Provide customer with all paperwork · Document the steps taken in the work-order and journal · Document any and all components used in the repair · Document amount of time spent to resolve the problem Chapter 5 Notes OS: Operating System Control Hardware Access The operating system manages the interaction between applications and the hardware. To access and communicate with the hardware, the operating system installs a device driver for each hardware component. Device driver: a small program written by the hardware manufacturer and supplied with the hardware component, which When the hardware is installed, so is the device driver, allowing the OS to communicate with the hardware component.PnP: Plug and Play: process of assigning system resources and installing drivers System Registry: a database that contains all the information about the computer. (The registry contains information about applications, users, hardware, network settings, and file types.) File and Folder Management The operating system creates a file structure on the hard disk drive to allow data to be stored. File: a block of related data that is given a single name and treated as a single unit. (Program and data files are grouped together in a directory). Directories are called folders. Subdirectories are called subfolders. User Interface There are two types of user interfaces: CLI: Command Line Interface– The user types commands at a prompt GUI: Graphical User Interface– The user interacts with menus and icons Windows 2000 and Windows XP, include both a GUI and a CLI. Application Management The operating system locates an application and loads it into the RAM of the computer. Applications: software programs, (I.e. word processors, databases, spreadsheets, games, etc) The operating system ensures that each application has adequate system resources. API: Application programming interface: a set of guidelines used by programmers to ensure that the application they are developing is compatible with an operating system. Here are two examples of APIs: OpenGL: Open Graphics Library– Cross-platform standard specification for multimedia graphics DirectX – Collection of APIs related to multimedia tasks for Microsoft Windows The following terms are often used when comparing operating systems: Multi-user – Two or more users can work with programs and share peripheral devices, such as printers, at the same time. Multi-tasking – The computer is capable of operating multiple applications at the same time. Multi-processing – The computer can have two or more central processing units (CPUs) that programs share. Multi-threading – A program can be broken into smaller parts that can be loaded as needed by the operating system. Multi-threading allows individual programs to be multi-tasked. Almost all modern operating systems are multi-user and multi-tasking, and they support multi-processing and multithreaading Modes of Operation: the capability of the CPU and the operating environment which determines how the CPU will manage applications and memory. Real Mode A CPU that operates in real mode can only execute one program at a time, and can only address 1 MB of system memory at a time. Although all modern processors have real mode available, it is only used by DOS and DOS applications or by 16-bit operating systems, such as Windows 3.x. In real mode, when an application creates an error, the entire computer can be affected due to; the program has direct access to memory. This can cause the computer to stop responding, restart, or shut down due to corruption of the memory space. Protected Mode A CPU that operates in protected mode has access to all of the memory in the computer, including virtual memory. Virtual memory: is hard disk space that is used to emulate RAM. (Operating systems that use protected mode can manage multiple programs simultaneously. Protected mode provides 32-bit access to memory, drivers, and transfers between input and output (I/O) devices. Protected mode is used by 32-bit operating systems, such as Windows 2000 or Windows XP. In protected mode, applications are protected from using the memory reserved for another application that is currently running.)Virtual Real Mode: Allows a real-mode application to run within a protected-mode operating system. (This can be demonstrated when a DOS application runs in a 32-bit operating system, such as Windows XP.) Compatibility Mode: creates the environment of an earlier operating system for applications that are not compatible with the current operating system. (I.e. An application that checks the version of the operating system may be written for Windows NT and require a particular service pack. Compatibility mode creates the proper environment or version of the operating system to allow the application to run as if it is in the intended environment.) A desktop operating system (Desktop OS) is intended for use in a small office/home office (SOHO) with a limited number of users. A network operating system (Network OS) is designed for a corporate environment serving multiple users with a wide range of needs. Desktop OS: Supports a single user Runs single-user applications Shares files and folders on a small network with limited security The most commonly used desktop operating systems fall into three groups: Microsoft Windows, Apple Mac OS, and UNIX/Linux. Microsoft Windows Windows is one of the most popular operating systems today. The following products are desktop versions of the Microsoft Windows operating systems: Windows XP Professional – Used on most computers that will connect to a Windows Server on a network Windows XP Home Edition – Used on home computers and has very limited security Windows XP Media Center – Used on entertainment computers for viewing movies and listening to music Windows XP Tablet PC Edition – Used for tablet PCs (Laptops /Blueberry’s) Windows XP 64-bit Edition – Used for computers with 64-bit processors Windows 2000 Professional – Older Windows operating system that has been replaced by XP Professional Windows Vista – Next to Newest version of Windows Windows 7 – Newest version of Windows Apple Mac OS Apple computers are proprietary and use an operating system called Mac OS. Mac OS is designed to be a userfrieendl GUI operating system. Current versions of Mac OS are now based on a customized version of UNIX. UNIX/Linux UNIX, which was introduced in the late 1960s, is one of the oldest operating systems. There are many different versions of UNIX today. One of the most recent is the extremely popular Linux, and it is designed as an open-source operating system. Open-source programs allow the source code to be distributed and changed by anyone as a free download or from developers at a much lower cost than other operating systems. A network OS has the following characteristics: Supports multiple users Runs multi-user applications Is robust and redundant Provides increased security compared to desktop operating systems These are the most common network operating systems: Microsoft Windows – Network operating systems offered by Microsoft are Windows 2000 Server and Windows Server 2003. Windows Server operating systems use a central database called Active Directory to manage network resources. Novell Netware – Novell NetWare was the first OS to meet network OS requirements and enjoy widespread deployment in PC-based LANs back in the 1980s. Linux – Linux operating systems include Red Hat, Caldera, SuSE, Debian, and Slackware. UNIX – Various corporations offered proprietary operating systems, based on UNIX. HCL: Hardware Compatibility List: provide a detailed inventory of hardware that has been tested and is known to work with the operating system and can be found on the manufacturer's website. These lists provide a detailed inventory of hardware that has been tested and is known to work with the operating system. Operating System Setup: The installation and initial booting of the operating system. Partition: logically divided into one or more areas Format: the partitions are prepared to hold files and applications. During the installation phase, most operating systems automatically partition and format the hard drive. Hard Drive setup: Primary partition – This partition is usually the first partition. A primary partition cannot be subdivided into smaller sections. There can be up to four partitions per hard drive. Active partition – This partition is the partition used by the operating system to boot the computer. Only one primary partition can be marked active. Extended partition – This partition normally uses the remaining free space on a hard drive or takes the place of a primary partition. There can be only one extended partition per hard drive, and it can be subdivided into smaller sections called logical drives. Logical drive – This drive is a section of an extended partition that can be used to separate information for administrative purposes. Formatting – This process prepares a file system in a partition for files to be stored. Sector – A sector contains a fixed number of bytes, at least 512. Cluster – A cluster is also called a file allocation unit. It is the smallest unit of space used for storing data. It is made up of one or more sectors. Track – A track is one complete circle of data on one side of a hard drive platter. A track is broken into groups of sectors. Cylinder – A cylinder is a stack of tracks lined up one on top of another to form a cylinder shape. Drive mapping – Drive mapping is a letter assigned to a physical or logical drive. The Windows XP operating system can use one of two file systems: File Allocation Table, 32-bit (FAT32) – A file system that can support partition sizes up to 2 TB or 2,048 GB. The FAT32 file system is supported by Windows 9.x, Windows Me, Windows 2000, and Windows XP. New Technology File System (NTFS) – A file system that can support partition sizes up to 16 exabytes, in theory. NTFS incorporates more file system security features and extended attributes than the FAT file system. Some user information is needed for the OS installation, some examples are: Standards and formats that define currency and numerals Text input language Name of the user and company Product key Computer name Administrator password Date and time settings Network settings Domain or workgroup information When a computer boots up with the Windows installation CD, the Windows XP installation starts with three options: Setup XP – To run the setup and install the XP operating system, press ENTER. Repair XP – To repair an installation, press R to open the Recovery Console. Quit – To quit Setup without installing Windows XP, press F3. Sysprep: Microsoft System Preparation: prepares an operating system that will be used on computers with different hardware configurations.SID: System Security Identifier Disk Cloning: creates an image of a hard drive in a computer. Follow these steps for disk cloning: 1. Create a master installation on one computer. (The operating system, software applications, and configuration settings that will be used by the other computers in the organization.) 2. Run Sysprep. 3. Create a disk image of the configured computer using a third-party disk-cloning program. 4. Copy the disk image onto a server. When the destination computer is booted, a shortened version of the Windows setup program runs. (The setup will create a new SID, install drivers for hardware, create user accounts, and configure network settings to finish the OS install.) POST: Power-On Self Test The Windows XP Boot Process To begin the boot process, you first turn on the computer, which is called a cold boot. The computer performs the POST. Because the video adapter has not yet been initialized, any errors that occur at this point in the boot process will be reported by a series of audible tones, called beep codes. After POST, the BIOS locates and reads the configuration settings that are stored in the CMOS. This configuration setting is the order in which devices will be tried to see if an operating system is located there. The BIOS boots the computer using the first drive that contains an operating system. Once the drive with the operating system is located, the BIOS locates the Master Boot Record (MBR). The MBR locates the operating system boot loader. For Windows XP, the boot loader is called NT Loader (NTLDR). NTLDR and the Windows Boot Menu At this point NTLDR controls several installation steps. For instance, if more than one OS is present on the disk, BOOT.INI gives the user a chance to select which one to use. If there are no other operating systems, or if the user does not make a selection before the timer expires, then the following steps occur: · NTLDR runs NTDETECT.COM to get information about installed hardware. · NTLDR then uses the path specified in the BOOT.INI to find the boot partition. · NTLDR loads two files that make up the core of XP: NTOSKRNL.EXE and HAL.DLL. · NTLDR reads the Registry files, chooses a hardware profile, and loads device drivers. The Windows Registry The Windows Registry files are an important part of the Windows XP boot process. These files are recognized by their distinctive names, which begin with HKEY_, followed by the name of the portion of the operating system under their control. The NT Kernel At this point, the NT kernel, the heart of the Windows operating system, takes over. The name of this file is NTOSKRNL.EXE. It starts the login file called WINLOGON.EXE and displays the XP welcome screen. Post-installation modifications: Msconfig – This boot configuration utility allows you to set the programs that will run at startup and to edit configuration files. Regedit – This application allows you to edit the registry. Startup Modes You can boot Windows in one of many different modes. Pressing the F8 key during the boot process opens the Windows Advanced Startup Options menu, which allows you to select how to boot Windows. The following startup options are commonly used: Safe Mode – Starts Windows but only loads drivers for basic components, such as the keyboard and display. Safe Mode with Networking Support – Starts Windows identically to Safe Mode and also loads the drivers for network components. Safe Mode with Command Prompt – Starts Windows and loads the command prompt instead of the GUI interface. Last Known Good Configuration – Enables a user to load the configurations settings of Windows that was used the last time that Windows successfully started. It does this by accessing a copy of the registry that is created for this purpose. Control Panel Applets The names of various applets in the Control Panel differ slightly depending on the version of Windows installed. In Windows XP, the icons are grouped into categories: · Appearance and Themes – applets that control the look of windows: ○ Display ○ Taskbar and Start menu ○ Folder options · Network and Internet Connections – applets that configure all of the connection types: ○ Internet options ○ Network connections · Add or Remove Programs – an applet to add or remove programs and windows components safely · Sounds, Speech, and Audio Devices – applets that control all of the settings for sound: ○ Sounds and audio devices ○ Speech ○ Portable Media Devices · Performance and Maintenance – applets to find information about your computer or perform maintenance: ○ Administrative tools ○ Power options ○ Scheduled tasks ○ System · Printers and Other Hardware – applets to configure devices connected to your computer: ○ Game controllers ○ Keyboard ○ Mouse ○ Phone and modem options ○ Printers and faxes ○ Scanners and cameras · User Accounts – applets to configure options for users and their e-mail: ○ E-mail ○ User accounts · Date, Time, Language, and Regional Options – applets to change settings based on your location and language: ○ Date and time ○ Regional and language options · Accessibility Options – a wizard used to configure windows for vision, hearing, and mobility needs · Security Center – applet used to configure security settings for: ○ Internet options ○ Automatic updates ○ Windows firewall Display Settings You can change the display settings by using the Display Settings applet. Change the appearance of the desktop by modifying the resolution and color quality. You can change more advanced display settings, such as wallpaper, screen saver, power settings, and other options. Task Manager The Task Manager, allows you to view all applications that are currently running and to close any applications that have stopped responding. The Task Manager allows you to monitor the performance of the CPU and virtual memory, view all processes that are currently running, and view information about the network connections. Event Viewer The Event Viewer, logs a history of events regarding applications, security, and the system. These log files are a valuable troubleshooting tool. Remote Desktop The Remote Desktop allows one computer to remotely take control of another computer. This troubleshooting feature is only available with Windows XP Professional. Performance Settings to enhance the performance of the operating system, you can change some of the settings that your computer uses, such as virtual memory configuration settings. Preventive Maintenance Planning Preventive maintenance plans should include detailed information about the maintenance of all computers and network equipment, with emphasis on equipment that could impact the organization the most. Preventive maintenance includes the following important tasks: · Updates to the operating system and applications · Updates to anti-virus and other protective software · Hard drive error checking · Hard drive backup · Hard drive defragmentation A preventive maintenance program that is designed to fix things before they break, and to solve small problems before they affect productivity, can provide the following benefits to users and organizations: · Decreased downtime · Improved performance · Improved reliability · Decreased repair costs Normal Backup: AKA a full backup: all selected files on the disk are archived to the backup medium; these files are marked as having been archived by clearing the archive bit. Copy Backup: copies all selected files. It does not mark the files as having been archived. Differential Backup: backs up all the files and folders that have been created or modified since either the last normal backup or the last incremental backup. The differential backup does not mark the files as having been archived. Incremental Backup: backs up all the files and folders that have been created or modified since either the last normal or incremental backup. It marks the files as having been archived by clearing the archive bit. Chapter 8 Notes Types of networks: LAN: Local Area Network: a group of interconnected devices that is under the same administrative control. WAN: Wide Area Network: networks that connect LANs in geographically separated locations. (I.e. Internet) WLAN: Wireless LAN: wireless devices are used to transmit and receive data using radio waves to connect to LANs TSP: Telecommunications service provider: used to interconnect these LANs at different locations. Networks: systems that are formed by links. Social networking sites: Websites that allow individuals to link to each other’s pages. Conceptual network: a set of related ideas. Personal network: The connections you have with all your friends. People use the following networks every day: Mail delivery system Telephone system Public transportation system Corporate computer network The Internet Computer data network: a collection of hosts connected by networking devices. Host: any device that sends and receives information on the network. Peripherals: devices that are connected to hosts. Types of devices that can connect to a network: Desktop computers, Laptop computers, Printers, Scanners, PDAs, Smart phones, File/print servers A network can share many different types of resources: Services, such as printing or scanning Storage space on removable devices, such as hard drives or optical drives Applications, such as databases Network devices link together using a variety of connections: Copper cabling: Uses electrical signals to transmit data between devices Fiber-optic cabling: Uses glass or plastic wire, also called fiber, to carry information as light pulses Wireless connection: Uses radio signals, infrared technology (laser), or satellite transmissions The benefits of networking computers and other devices include lower costs and increased productivity. With networks, resources can be shared, which results in less duplication and corruption of data. Fewer Peripherals Needed Many devices can be connected on a network. Each computer on the network does not need to have its own printer, scanner, or backup device. Increased Communication Capabilities Networks provide several different collaboration tools that can be used to communicate between network users. Online collaboration tools include e-mail, forums and chats, voice and video and instant messaging. Avoid File Duplication and Corruption A server manages network resources. Servers store data and share it with users on a network. Confidential or sensitive data can be protected and shared with the users who have permission to access that data. Lower Cost Licensing Application licensing can be expensive for individual computers. The site license allows a group of people or an entire organization to use the application for a single fee. Centralized Administration Centralized administration reduces the number of people needed to manage the devices and data on the network, reducing time and cost to the company. Individual network users do not need to manage their own data and devices. One administrator can control the data, devices, and permissions of users on the network. Backing up data is easier because the data is stored in a central location. Conserve Resources Data processing can be distributed across many computers to prevent one computer from becoming overloaded with processing tasks. Peer-to-peer network: no dedicated servers or hierarchy among the computers, each device has equivalent capabilities and responsibilities. Individual users are responsible for their own resources and can decide which data and devices to share. Client/server network: client requests information or services from the server. The server provides the requested information or service to the client. Servers on a client/server network commonly perform some of the processing work for client machines. Bandwidth: amount of data that can be transmitted within a fixed time period: is measured in bits per second and is usually denoted by any of the following units of measure: · bps – bits per second · kbps – kilobits per second · Mbps – megabits per second NOTE: One byte is equal to 8 bits, and is abbreviated with a capital B. Simplex: AKA unidirectional: a single, one-way transmission. Half-duplex: an alternating transmission in two directions, but not in both directions simultaneously. Full-Duplex: data flows in both directions at the same time. IP address consists of a series of 32 binary bits The logical 32-bit IP address is hierarchical and is composed of two parts. The first part identifies the network and the second part identifies a host on that network. Both parts are required in an IP address. As an example, if a host has IP address 192.168.18.57, the first three octets, 192.168.18, identify the network portion of the address, and the last octet, 57 identifies the host. IP addresses are divided into the following five classes: · Class A – Large networks, implemented by large companies and some countries · Class B – Medium-sized networks, implemented by universities · Class C – Small networks, implemented by ISP for customer subscriptions · Class D – Special use for multicasting · Class E – Used for experimental testing Subnet mask: used to indicate the network portion of an IP address. Default subnet masks for usable IP addresses that are mapped to the first three classes of IP addresses: · 255.0.0.0 – Class A, which indicates that the first octet of the IP address is the network portion · 255.255.0.0 – Class B, which indicates that the first two octets of the IP address is the network portion · 255.255.255.0 – Class C, which indicates that the first three octets of the IP address is the network portion Manual Configuration: a network with a small number of hosts, it is easy to manually configure each device with the proper IP address. DHCP: Dynamic Host Configuration Protocol: a software utility used to dynamically assign IP addresses to network devices. Data networks continue to evolve in complexity, use, and design. To communicate about networks, different types of networks are given different descriptive names.IP address information that a DHCP server can assign to hosts: · IP address · Subnet mask · Default gateway · Optional values, such as a Domain Name System (DNS) server address APIPA: Automatic Private IP Addressing: If your computer cannot communicate with the DHCP server to obtain an IP address and will continually request an IP address from a DHCP server for your computer. Protocol: a set of rules. Internet protocol: sets of rules governing communication within and between computers on a network. Protocol specifications: defines the format of the messages that are exchanged. These are the main functions of protocols: · Identifying errors · Compressing the data · Deciding how data is to be sent · Addressing data · Deciding how to announce sent and received data ICMP: Internet Control Message Protocol: used by devices on a network to send control and error messages to computers and servers. Packet internet groper (ping): commonly used to test connections between computers. These are the most common devices on a network: · Computers · Hubs · Switches · Routers · Wireless access points These are the most common media used on networks: · Twisted-pair · Fiber-optic cabling · Radio waves Hubs: devices that extend the range of a network by receiving data on one port, and then regenerating the data and sending it out to all other ports. Bridges and Switches: a device used to filter network traffic between LAN segments and keep a record of all the devices on each segment to which the bridge is connected. Router: use IP addresses to forward frames to other networks. Wireless Access Points: provide network access to wireless devices such as laptops and PDAs. Multipurpose Devices: There are network devices that perform more than one function. Twisted-Pair: a type of copper cabling that is used for telephone communications and most Ethernet networks. · Unshielded twisted-pair (UTP) – Cable that has two or four pairs of wires. This type of cable relies solely on the cancellation effect produced by the twisted-wire pairs that limits signal degradation caused by electromagnetic interface (EMI) and radio frequency interference (RFI). UTP is the most commonly used cabling in networks. UTP cables have a range of 328 feet (100 m). · Shielded twisted-pair (STP) – Each pair of wires is wrapped in metallic foil to better shield the wires from noise. Four pairs of wires are then wrapped in an overall metallic braid or foil. STP reduces electrical noise from within the cable. It also reduces EMI and RFI from outside the cable. Coaxial Cable: a copper-cored cable surrounded by a heavy shielding. Coaxial cable is used to connect computers in a network. Thicknet or 10BASE5 – Coax cable that was used in networks and operated at 10 megabits per second with a maximum length of 500 meters Thinnet 10BASE2 – Coax cable that was used in networks and operated at 10 megabits per second with a maximum length of 185 meters RG-59 – Most commonly used for cable television in the U.S. RG-6 – Higher quality cable than RG-59, with more bandwidth and less susceptibility to interference Fiber-Optic Cable: a glass or plastic conductor that transmits information using light. These are the two types of glass fiber-optic cable: · Multimode – Cable that has a thicker core than single-mode cable. It is easier to make, can use simpler light sources (LEDs), and works well over distances of a few kilometers or less. · Single-mode – Cable that has a very thin core. It is harder to make, uses lasers as a light source, and can transmit signals dozens of kilometers with ease. Topologies: commonly represented as network diagrams. There are two types of LAN topologies: · Physical Topology: the physical layout of the components on the network. · Logical Topology: determines how the hosts communicate across a medium, such as a cable or the airwaves. LAN architecture is built around a topology. LAN architecture comprises all the components that make up the structure of a communications system. These components include the hardware, software, protocols, and sequence of operations. Physical Topologies: · Bus · Ring · Star · Hierarchical or Extended Star · Mesh Bus Topology: each computer connects to a common cable. The cable connects one computer to the next, like a bus line going through a city. Ring Topology: hosts are connected in a physical ring or circle. Because the ring topology has no beginning or end, the cable does not need to be terminated. Star Topology: has a central connection point, which is normally a device such as a hub, switch, or router. Each host on a network has a cable segment that attaches the host directly to the central connection point. Hierarchical or Extended Star Topology: a star network with an additional networking device connected to the main networking device. Mesh Topology: connects all devices to each other. When every device is connected to every other device, a failure of any cable will not affect the network. The mesh topology is used in WANs that interconnect LANs.Logical Topologies Broadcast Topology: host addresses either data to a particular host or to all hosts connected on a network. 1st come 1st serve. Token passing: controls network access by passing an electronic token sequentially to each host. When a host receives the token, it can send data on the network. If the host has no data to send, it passes the token to the next host and the process repeats itself. Ethernet the Ethernet architecture is based on the IEEE 802.3 standard. The IEEE 802.3 standard specifies that a network use the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access control method. Token Ring Token Ring as a reliable network architecture based on the token-passing access control method. FDDI: Fiber distributed data interface: is a type of Token Ring network and is often used to connect several buildings in an office complex or on a university campus. Ethernet Technologies The IEEE 802.3 standard defines several physical implementations that support Ethernet. Some of the common implementations are described here. Ethernet 10BASE-T is an Ethernet technology that uses a star topology. 10BASE-T is a popular Ethernet architecture whose features are indicated in its name: · The ten (10) represents a speed of 10 Mbps. · BASE represents baseband transmission. In baseband transmission, the entire bandwidth of a cable is used for one type of signal. · The T represents twisted-pair copper cabling. Advantages of 10BASE-T: · Installation of cable is inexpensive compared to fiber-optic installation. · Cables are thin, flexible, and easier to install than coaxial cabling. · Equipment and cables are easy to upgrade. Disadvantages of 10BASE-T: · The maximum length for a 10BASE-T segment is only 328 feet (100 m). · Cables are susceptible to electromagnetic interference (EMI). Fast Ethernet the high bandwidth demands of many modern applications, such as live video conferencing and streaming audio, have created a need for higher data-transfer speeds. Many networks require more bandwidth than 10 Mbps Ethernet. 100BASE-TX is much faster than 10BASE-T and has a theoretical bandwidth of 100 Mbps. Advantages of 100BASE-TX: · At 100 Mbps, transfer rates of 100BASE-TX are ten times that of 10BASE-T. · 100BASE-X uses twisted-pair cabling, this is inexpensive and easy to install. Disadvantages of 100BASE-TX: · The maximum length for a 100BASE-TX segment is only 328 feet (100 m). · Cables are susceptible to electromagnetic interference (EMI). 1000BASE -T: Gigabit Ethernet. Gigabit Ethernet is a LAN architecture. Advantages of 1000BASE-T: · The 1000BASE-T architecture supports data transfer rates of 1 Gbps. At 1 Gbps, it is ten times faster than Fast Ethernet, and 100 times faster than Ethernet. This increased speed makes it possible to implement bandwidth-intensive applications, such as live video. · The 1000BASE-T architecture has interoperability with 10BASE-T and 100BASE-TX. Disadvantages of 1000BASE-T: · The maximum length for a 1000BASE-T segment is only 328 feet (100 m). · It is susceptible to interference. · Gigabit NICs and switches are expensive. · Additional equipment is required. 10BASE-FL, 100BASE-FX, 1000BASE-SX and LX are fiber-optic Ethernet Technologies. IEEE 802.11 is the standard that specifies connectivity for wireless networks. IEEE 802.11, or Wi-Fi, refers to the collective group of standards – 802.11a, 802.11b, 802.11g, and 802.11n. 802.11a Devices conforming to the 802.11a standard allow WLANs to achieve data rates as high as 54 Mbps. IEEE 802.11a devices operate in the 5 GHz radio frequency range and within a maximum range of 150 feet (45.7 m). 802.11b 802.11b operates in the 2.4 GHz frequency range with a maximum theoretical data rate of 11 Mbps. These devices operate within a maximum range of 300 feet (91 m). 802.11g IEEE 802.11g provides the same theoretical maximum speed as 802.11a, which is 54 Mbps, but operates in the same 2.4 GHz spectrum as 802.11b. Unlike 802.11a, 802.11g is backward-compatible with 802.11b. 802.11g also has a maximum range of 300 feet (91 m). 802.11n 802.11n is a newer wireless standard that has a theoretical bandwidth of 540 Mbps and operates in either the 2.4 GHz or 5 GHz frequency range with a maximum range of 984 feet (250 m). Application Protocols: provide network services to user applications such as web browsers and e-mail programs. Transport Protocols: provides end-to-end management of the data. One of the functions of these protocols is to divide the data into manageable segments for easier transport across the network. Internet Protocols: operate in the third layer from the top in the TCP/IP model. These protocols are used to provide connectivity between hosts in the network. Network Access Protocols: describe the standards that hosts use to access the physical media. The IEEE 802.3 Ethernet standards and technologies, such as CSMA/CD and 10BASE-T are defined in this layer. Protocol Stack: A system that implements protocol behavior consisting of a series of these layers. Protocol stacks can be implemented either in hardware or software, or a combination of both. PDU: protocol data units: describes data as it moves from one layer of the OSI model to another. At the Transport layer, the data is broken down into more manageable segments, or Transport layer (PDUs), for orderly transport across the network. The Transport layer PDU also contains information such as port numbers, sequence numbers, and acknowledgement numbers, which is used for reliable data transport. At the Network layer, each segment from the Transport layer becomes a packet. The packet contains logical addressing and other layer-3 control information. At the Data Link layer, each packet from the Network layer becomes a frame. The frame contains physical address and error correction information. At the Physical layer, the frame becomes bits. These bits are transmitted one at a time across the network medium. At the receiving computer, the de-encapsulation process reverses the process of encapsulation. The bits arrive at the Physical layer of the OSI model of the receiving computer. The process of virtually traveling up the OSI model of the receiving computer will bring the data to the Application layer, where an e-mail program will display the e-mail. The OSI model and the TCP/IP model are both reference models used to describe the data communication process. Every NIC must be configured with the following information:· Protocols – The same protocol must be implemented between any two computers that communicate on the same network. · IP address – This address is configurable and must be unique to each device. The IP address can be manually configured or automatically assigned by DHCP. · MAC address – Each device has a unique MAC address. The MAC address is assigned by the manufacturer and cannot be changed. Analog Telephone This technology uses standard voice telephone lines. This type of service uses a modem to place a telephone call to another modem at a remote site, such as an Internet Service provider. Integrated Services Digital Network (ISDN) The next advancement in WAN service is ISDN. ISDN is a standard for sending voice, video, and data over normal telephone wires. ISDN technology uses the telephone wires as an analog telephone service. However, ISDN uses digital technology to carry the data. Because it uses digital technology, ISDN provides higher-quality voice and higher-speed data transfer than traditional analog telephone service. Digital Subscriber Line (DSL) DSL is an "always-on" technology. “Always on” means that there is no need to dial up each time to connect to the Internet. DSL uses the existing copper telephone lines to provide high-speed digital data communication between end users and telephone companies. Asymmetric Digital Subscriber Line (ADSL) ADSL is currently the most commonly used DSL technology. ADSL has different bandwidth capabilities in each direction. ADSL has a fast downstream speed – typically 1.5 Mbps. Downstream is the process of transferring data from the server to the end user. Power line communication (PLC) is a communication method that uses power distribution wires (local electric grid) to send and receive data. PLC is known by other names: · Power Line Networking (PLN) · Mains Communication · Power Line Telecoms (PLT) With PLC, an electric company can superimpose an analog signal over the standard 50 or 60 Hz AC that travels in power lines. The analog signal can carry voice and data signals. Cable a cable modem connects your computer to the cable company using the same coaxial cable that connects to your cable television. A cable modem is shown in the figure. You can plug your computer directly into the cable modem, or you can connect a router, switch, hub, or multipurpose network device so that multiple computers can share the connection to the Internet. DSL With DSL, the voice and data signals are carried on different frequencies on the copper telephone wires. A filter is used to prevent DSL signals from interfering with phone signals. A DSL filter is shown in the figure. Plug the filter into a phone jack and plug the phone into the filter. The DSL modem does not require a filter. The DSL modem is not affected by the frequencies of the telephone. Like a cable modem, a DSL modem can connect directly to your computer, or it can be connected to a networking device to share the Internet connection with multiple computers. ISDN ISDN is another example of broadband. ISDN uses multiple channels and can carry different types of services; therefore, it is considered a type of broadband. ISDN can carry voice, video, and data. Satellite Broadband satellite is an alternative for customers who cannot get cable or DSL connections. A satellite connection does not require a phone line or cable, but uses a satellite dish for two-way communication. Download speeds are typically up to 500 Kbps; uploads are closer to 56 Kbps. It takes time for the signal from the satellite dish to relay to your Internet Service Provider (ISP) through the satellite orbiting the Earth. Voice over IP (VoIP) is a method to carry telephone calls over the data networks and Internet. VoIP converts the analog signals of our voices into digital information that is transported in IP packets. VoIP can also use an existing IP network to provide access to the public switched telephone network (PSTN). A computer network is composed of two or more computers that share data and resources. A Local Area Network (LAN) refers to a group of interconnected computers that are under the same administrative control. A Wide Area Network (WAN) is a network that connects LANs in geographically separated locations. In a peer-to-peer network, devices are connected directly to each other. A peer-to-peer network is easy to install, and no additional equipment or dedicated administrator is required. Users control their own resources, and a network works best with a small number of computers. A client/server network uses a dedicated system that functions as the server. The server responds to requests made by users or clients connected to the network. A LAN uses a direct connection from one computer to another. It is suitable for a small area, such as in a home, building, or school. A WAN uses point-to-point or point-to-multipoint, serial communications lines to communicate over greater distances. A WLAN uses wireless technology to connect devices together. The network topology defines the way in which computers, printers, and other devices are connected. Physical topology describes the layout of the wire and devices, as well as the paths used by data transmissions. Logical topology is the path that signals travel from one point to another. Topologies include bus, star, ring, and mesh. Networking devices are used to connect computers and peripheral devices so that they can communicate. These include hubs, bridges, switches, routers, and multipurpose devices. The type of device implemented depends on the type of network. Networking media can be defined as the means by which signals, or data, are sent from one computer to another. Signals can be transmitted either by cable or wireless means. The media types discussed were coaxial, twisted-pair, fiber-optic cabling, and radio frequencies. Ethernet architecture is now the most popular type of LAN architecture. Architecture refers to the overall structure of a computer or communications system. It determines the capabilities and limitations of the system. The Ethernet architecture is based on the IEEE 802.3 standard. The IEEE 802.3 standard specifies that a network implement the CSMA/CD access control method. The OSI reference model is an industry standard framework that is used to divide the functions of networking into seven distinct layers. These layers include Application, Presentation, Session, Transport, Network, Data Link, and Physical. It is important to understand the purpose of each layer. The TCP/IP suite of protocols has become the dominant standard for the Internet. TCP/IP represents a set of public standards that specify how packets of information are exchanged between computers over one or more networks. A NIC is a device that plugs into a motherboard and provides ports for the network cable connections. It is the computer interface with the LAN. A modem is an electronic device that is used for computer communications through telephone lines. It allows data transfer between one computer and another. The modem converts byte-oriented data to serial bit streams. All modems require software to control the communication session. The set of commands that most modem software uses is known as the Hayes-compatible command set. The three transmission methods to sending signals over data channels are simplex, half-duplex, and full-duplex. Full-duplex networking technology increases performance because data can be sent and received at the same time. DSL, two-way cable modem, and other broadband technologies operate in full-duplex mode. Network devices and media, such as computer components, must be maintained. It is important to clean equipment regularly and use a proactive approach to prevent problems. Repair or replace broken equipment to prevent downtime. When troubleshooting network problems, listen to what your customer tells you so that you can formulate openennde and closed-ended questions that will help you determine where to begin fixing the problem. Verify obvious issues and try quick solutions before escalating the troubleshooting process. Chapter 9 Notes Computer and network security help to keep data and equipment functioning and provide access only to appropriate people. To successfully protect computers and the network, a technician must understand both types of threats to computer security: · Physical – Events or attacks that steal, damage, or destroy equipment, such as servers, switches, and wiring · Data – Events or attacks that remove, corrupt, deny access, allow access, or steal information Threats to security can come from the inside or outside of an organization, and the level of potential damage can vary greatly: · Internal – Employees have access to data, equipment, and the network ○ Malicious threats are when an employee intends to cause damage. ○ Accidental threats are when the user damages data or equipment unintentionally. · External – Users outside of an organization that do not have authorized access to the network or resources ○ Unstructured – Attackers use available resources, such as passwords or scripts, to gain access and run programs designed to vandalize ○ Structured – Attackers use code to access operating systems and software Virus: a program written with malicious intent and sent out by attackers and it hides by attaching itself to a file on the computer then virus is transferred to another computer through e-mail, file transfers, and instant messaging. Stealth Virus: infects a computer and lays dormant until summoned by the attacker. Worm: a self-replicating program that is harmful to networks and uses the network to duplicate its code to the hosts on a network, often without any user intervention. It does not need to attach to a program to infect a host. Trojan: technically a worm, it does not need to be attached to other software. Instead it is hidden in software that appears to do one thing, and yet behind the scenes it does another. Trojans are often disguised as useful software and can reproduce like a virus and spread to other computers. Adware, spyware, and gray ware are usually installed on a computer without the knowledge of the user. These programs collect information stored on the computer, change the computer configuration, or open extra windows on the computer without the user’s consent. Adware is a software program that displays advertising on your computer. Adware is usually distributed with downloaded software. Malware is a file or program other then a virus that is potentially harmful. Many gray ware attacks are phishing attacks that try to persuade the reader to unknowingly provide attackers with access to personal information. Spyware, a type of gray ware, is similar to adware. It is distributed without any user intervention or knowledge. Once installed, the spyware monitors activity on the computer. The spyware then sends this information to the organization responsible for launching the spyware. Phishing is a form of social engineering where the attacker pretends to represent a legitimate outside organization, such as a bank. Denial of service (DoS) is a form of attack that prevents users from accessing normal services, such as e-mail and a web server, because the system is busy responding to abnormally large amounts of requests. DoS works by sending enough requests for a system resource that the requested service is overloaded and ceases to operate.Common DoS attacks include the following: · Ping of death – A series of repeated, larger than normal pings that crash the receiving computer · E-mail bomb – A large quantity of bulk e-mail that overwhelms the e-mail server preventing users from accessing it Distributed DoS (DDoS) is another form of attack that uses many infected computers, called zombies, to launch an attack. With DDoS, the intent is to obstruct or overwhelm access to the targeted server. Zombie computers located at different geographical locations make it difficult to trace the origin of the attack. Spam, also known as junk mail, is unsolicited e-mail. In most cases, spam is used as a method of advertising. However, spam can be used to send harmful links or deceptive content. Social Engineer: a person who is able to gain access to equipment or a network by tricking people into providing the necessary access information. Often, the social engineer gains the confidence of an employee and convinces the employee to divulge username and password information. Some of the most common attacks: · SYN Flood – Randomly opens TCP ports, tying up the network equipment or computer with a large amount of false requests, causing sessions to be denied to others · DoS – Sends abnormally large amounts of requests to a system preventing access to the services · DDoS – Uses "zombies" to make tracing the origin of the DoS attack difficult to locate · Spoofing – Gains access to resources on devices by pretending to be a trusted computer · Man-in-the-Middle – Intercepts or inserts false information in traffic between two hosts · Replay – Uses network sniffers to extract usernames and passwords to be used at a later date to gain access · DNS Poisoning – Changes the DNS records on a system to point to false servers where the data is recorded Hardware deconstruction is the process of removing sensitive data from hardware and software before recycling or discarding. Hard drives should be fully erased to prevent the possibility of recovery using specialized software. There are several methods of physically protecting computer equipment: · Control access to facilities · Use cable locks with equipment · Keep telecommunication rooms locked · Fit equipment with security screws · Use security cages around equipment · Label and install sensors, such as Radio Frequency Identification (RFID) tags, on equipment For access to facilities, there are several means of protection: · Card keys that store user data, including level of access · Biometric sensors that identify physical characteristics of the user, such as fingerprints or retinas · Posted security guard · Sensors, such as RFID tags, to monitor equipment Password Protection Password protection can prevent unauthorized access to content, as shown in Figure 1. Attackers are able to gain access to unprotected computer data. All computers should be password protected. Two levels of password protection are recommended:· BIOS – Prevents BIOS settings from being changed without the appropriate password · Login – Prevents unauthorized access to the network A good security policy should be strictly enforced and include, but not be limited to, the following rules: · Passwords should expire after a specific period of time. · Passwords should contain a mixture of letters and numbers so that they cannot easily be broken. · Password standards should prevent users from writing down passwords and leaving them unprotected from public view. · Rules about password expiration and lockout should be defined. Lockout rules apply when an unsuccessful attempt has been made to access the system or when a specific change has been detected in the system configuration. To simplify the process of administrating security, it is common to assign users to groups, and then to assign groups to resources. This allows the access capability of users on a network to be changed easily by assigning or removing the user from various groups. Data Encryption encrypting data uses codes and ciphers. Traffic between resources and computers on the network can be protected from attackers monitoring or recording transactions by implementing encryption. Virtual Private Network (VPN) uses encryption to protect data. A VPN connection allows a remote user to safely access resources as if their computer is physically attached to the local network. Port Protection every communication using TCP/IP is associated with a port number. HTTPS, for instance, uses port 443 by default. A firewall, as shown in Figure 2, is a way of protecting a computer from intrusion through the ports. The user can control the type of data sent to a computer by selecting which ports will be open and which will be secured. Data being transported on a network is called traffic. Data Backups Data backup procedures should be included in a security plan. Data can be lost or damaged in circumstances such as theft, equipment failure, or a disaster such as a fire or flood. Backing up data is one of the most effective ways of protecting against data loss. Here are some considerations for data backups: · Frequency of backups – Backups can take a long time. Sometimes it is easier to make a full backup monthly or weekly, and then do frequent partial backups of any data that has changed since the last full backup. However, spreading the backups over many recordings increases the amount of time needed to restore the data. · Storage of backups – Backups should be transported to an approved offsite storage location for extra security. The current backup media is transported to the offsite location on a daily, weekly, or monthly rotation as required by the local organization. · Security of backups – Backups can be protected with passwords. These passwords would have to be entered before the data on the backup media could be restored. File System Security All file systems keep track of resources, but only file systems with journals can log access by user, date, and time. The FAT 32 file system, which is used in some versions of Windows, lacks both journaling and encryption capabilities. As a result, situations that require good security are usually deployed using a file system such as NTFS, which is part of Windows 2000 and Windows XP. If increased security is needed, it is possible to run certain utilities, such as CONVERT, to upgrade a FAT 32 file system to NTFS. The conversion process is not reversible. It is important to clearly define your goals before making the transition. Wired Equivalent Privacy (WEP) – the first generation security standard for wireless. Attackers quickly discovered that WEP encryption was easy to break. The encryption keys used to encode the messages could be detected by monitoring programs. Once the keys were obtained, messages could be easily decoded. Wi-Fi Protected Access (WPA) – an improved version of WEP. It was created as a temporary solution until the 802.11i (a security layer for wireless systems) was fully implemented. Now that 802.11i has been ratified, WPA2 has been released. It covers the entire 802.11i standard. Lightweight Extensible Authentication Protocol (LEAP) also called EAP-Cisco – a wireless security protocol created by Cisco to address the weaknesses in WEP and WPA. LEAP is a good choice when using Cisco equipment in conjunction with operating systems like Windows and Linux. Wireless Transport Layer Security (WTLS): a security layer used in mobile devices that employ the Wireless Applications Protocol (WAP). Mobile devices do not have a great deal of spare bandwidth to devote to security protocols. WTLS was designed to provide security for WAP devices in a bandwidth-efficient manner. Chapter 10 Notes Determine the type of computer problem that the customer is experiencing. Remember these three rules at the beginning of your conversation: · Know – Call your customer by name · Relate – Use brief communication to create a one-to-one connection between you and your customer · Understand – Determine the customer's level of knowledge about the computer to know how to effectively communicate with the customer · Talkative Customer A talkative customer discusses everything except the problem on the call. The customer often uses the call as an opportunity to socialize. It can be difficult to get a talkative customer to focus on the problem. · Rude Customer a rude customer complains during the call and often makes negative comments about the product, the service, and the technician. This type of customer is sometimes abusive and uncooperative and gets aggravated very easily. · Angry Customer An angry customer talks loudly during the call and often tries to speak when the technician is talking. Angry customers are usually frustrated that they have a problem and upset that they have to call somebody to fix it. · Knowledgeable Customer a knowledgeable customer wants to speak with a technician that is equally experienced in computers. This type of customer usually tries to control the call and does not want to speak with a level-one technician. · Inexperienced Customer An inexperienced customer has difficulty describing the problem. These customers are usually not able to follow directions correctly and not able to communicate the errors that they encounter. For e-mail and text communications, there is a set of personal and business etiquette rules called Netiquette. In addition to the e-mail and text Netiquette, there are general rules that apply to all of your online interactions with customers and coworkers: · Remember that you are dealing with people. · Adhere to the same standards of behavior that you follow in real life. · Know where you are in cyberspace. · Respect other people's time and bandwidth. · Share expert knowledge. · Do not engage in "flame wars" online. · Respect other people's privacy. · Be forgiving of other people's mistakes. Workstation Ergonomics The ergonomics of your work area can help you do your job or make it more difficult. Because you may spend a major portion of your day at your workstation, make sure that the desk layout works well, as shown in Figure 1. Have your headset and phone in a position that is both easy to reach and easy to use. Your chair should be adjusted to a height that is comfortable. Adjust your computer screen to a comfortable angle so that you do not have to tilt your head up or down to see it. Make sure your keyboard and mouse are also in a position that is comfortable for you. You should not have to bend your wrist in order to type. If possible, try to minimize external distractions such as noise. Time Management For time management, it is important to prioritize your activities. Make sure that you carefully follow the business policy of your company. The company policy may state that you must take "down" calls first, even though they may be harder to solve. A "down" call usually means that a server is not working and the entire office or company is waiting for the problem to be resolved in order to resume business. If you have to call back a customer, make sure that you do it as close to the callback time as possible. Keep a list of callback customers and check them off one at a time as you complete these calls. Doing this will ensure that you do not forget a customer. When working with many customers, do not give favorite customers faster or better service. When reviewing the call boards, do not take only the easy customer calls. See Figure 2 for a sample customer call board. Do not take the call of another technician unless you have permission to do so. Stress Management for stress management; take a moment to compose yourself between customer calls. Every call should be independent of each other, and you should not carry any frustrations from one call to the next. You may have to do some physical activity to relieve stress. You should stand up and take a short walk. Do a few simple stretch movements or squeeze a tension ball. Take a break if you can, and try to relax. You will then be ready to answer the next customer call effectively. Service Level Agreement (SLA): a contract that defines expectations between an organization and the service vendor to provide an agreed upon level of support. As an employee of the service company, your job is to honor the SLA that you have with the customer. Some of the contents of an SLA usually include the following: · Response time guarantees (often based on type of call and level of service agreement) · Equipment and/or software that will be supported · Where service will be provided · Preventive maintenance · Diagnostics · Part availability (equivalent parts) · Cost and penalties · Time of service availability (for example, 24X7; Monday to Friday, 8 am to 5 pm EST; and so on) There may be exceptions to the SLA. Make sure to follow your company business rules in detail. Some of the exceptions may include the ability of the customer to upgrade level of service, or the ability to escalate to management for review. Escalation to management should be reserved for special situations. Customer Call Rules the following rules are examples of the specific rules a call center may have to handle customer calls: · Maximum time on call (Example: 15 minutes) · Maximum call time in queue (Example: three minutes) · Number of calls per day (Example: Minimum of 30) · Rules on passing calls on to other technicians (Example: Only when absolutely necessary and not without that technician's permission) · Rules on what you can and cannot promise to the customer (See that customer's SLA for details) · When to follow SLA and when to escalate to management Call Center Employee Rules There are also other rules to cover general daily activities of employees: · Arrive at your workstation early enough to become prepared, usually about 15 to 20 minutes before the first call. · Do not exceed the allowed number and length of breaks. · Do not take a break or go to lunch if there is a call on the board. · Do not take a break or go to lunch at the same time as other technicians (stagger breaks among technicians). · Do not leave an ongoing call to take a break or go to lunch. · Make sure that another technician is available if you have to leave. · If no other technician is available, check with the customer to see if you can call back later, possibly in the morning. · Do not show favoritism to certain customers. · Do not take another technician's calls without permission. · Do not talk negatively about the capabilities of another technician. Ethical Customs you should always have respect for your customers, as well as for their property. Property includes any information or data that may be accessible. Such information or data would include any of the following items: · E-mails · Phone lists · Records or data on the computer · Hard copies of files, information, or data left on desk Before accessing a computer account, including the administrator account, you should get the permission of the customer. From the troubleshooting process, you may have gathered some private information, such as usernames and passwords. If you document this type of private information, you must keep it confidential. Divulging any customer information to anyone else is not only unethical, but may be illegal. Legal details of customer information are usually covered under the SLA. Do not send unsolicited messages to a customer. Do not send unsolicited mass mailings or chain letters to customers. Never send forged or anonymous e-mails. All of these activities are considered unethical and in certain circumstances, may be considered illegal. Legal Rules There are several computer-related activities that are not only unethical, but are definitely illegal. Be aware that this is not an exhaustive list: · Do not make any changes to system software or hardware configurations without customer permission. · Do not access a customer's or co-worker's accounts, private files, or e-mail messages without permission. · Do not install, copy, or share digital content (including software, music, text, images, and video) in violation of copyright and/or software agreements or applicable federal and state law. · Do not use a customer's company IT resources for commercial purposes. · Do not make a customer's IT resources available to unauthorized users. · Keep sensitive customer information confidential. · Do not knowingly use a customer's company resources for illegal activities. Criminal or illegal use may include obscenity, child pornography, threats, harassment, copyright infringement, university trademark infringement, defamation, theft, identity theft, and unauthorized access. Call Center Environment: is usually very professional and fast-paced. It is a help desk system where customers call in and are placed on a callboard. Available technicians take the customer calls. A technician must supply the level of support that is outlined in the customer's SLA. Call center may exist within a company and offer service to the employees of that company as well as to the customers of that company's products. Alternatively, a call center may be an independent business that sells computer support as a service to outside customers. In either case, a call center will be a busy, fast-paced work environment, often operating 24 hours a day. All of the computers in a call center will have help desk software. The technicians use this software to manage many of their job functions. Call centers sometimes have different names for level-one technicians. These technicians may be known as level-one analysts, dispatchers, or incident screeners. The primary responsibility of a level-one technician is to gather pertinent information from the customer. The technician has to document all information in the ticket or work order. Some problems are very simple to resolve and a level-one technician can usually take care of these without escalating the work order to a level-two technician. Often, a problem requires the expertise of a level-two technician. In these cases, the level-one technician must be able to translate a customer's problem description into a succinct sentence or two that is entered into the work order. This translation is important so that other technicians can quickly understand the situation without having to ask the customer the same questions again. These technicians may be known as product specialists or technical-support personnel. The level-two technician's responsibilities are generally the same from one call center to the next. The level-two technician is usually more knowledgeable than the level-one technician about technology, or has been working for the company for a longer period of time. When a problem cannot be resolved within ten minutes, the level-one technician prepares an escalated work order. These are generic guidelines; you should follow your company's business policy for problem escalation. · Escalate problems that require opening the computer case. · Escalate problems that require installation of applications, operating systems, or drivers. · Escalate problems that will take a long time to walk a customer through -like CMOS changes. · Escalate down calls. The entire network is down, and a more experienced tech may be able to resolve the issue faster. Problems that require opening up the computer will need a level-two technician. Level-two technicians can also use remote diagnostic software to connect to the customer's computer in order to update drivers and software, access the operating system, check BIOS, and gather other diagnostic information to solve the problem. The following concepts from this chapter are important to remember: · To be a successful technician, you will need to practice good communication skills with customers and coworkkers These skills are as important as technical expertise. · You should always conduct yourself in a professional manner with your customers and co-workers. Professional behavior increases customer confidence and enhances your credibility. You should also learn to recognize the classic signs of a difficult customer and learn what to do and what not to do when you are on a call with this customer. · There are a few techniques that you can use to keep a difficult customer focused on the problem during a call. Primarily, you must remain calm and ask pertinent questions in an appropriate fashion. These techniques keep you in control of the call. · There is a right way and a wrong way to put a customer on hold, or transfer a customer to another technician. Learn and use the right way every time. Doing either of these operations incorrectly can cause serious damage to your company's relationship with its customers. · Netiquette is a list of rules to use whenever you communicate through e-mail, text messaging, instant messaging, or blogs. This is another area where doing things the wrong way can cause damage to your company's relationship with its customers. · You must understand and comply with your customer's service level agreement (SLA). If the problem falls outside the parameters of the SLA, you need to find positive ways of telling the customer what you can do to help, and not what you cannot do. In special circumstances, you may decide to escalate the work order to management. · In addition to the SLA, you must follow the business policies of the company. These policies will include how your company prioritizes calls, how and when to escalate a call to management, and when you are allowed to take breaks and lunch. · A computer technician's job is stressful. You will rarely get to meet a customer who is having a good day. You can alleviate some of the stress by setting up your workstation in the most ergonomically beneficial way possible. You should practice time and stress management techniques every day. · There are ethical and legal aspects of working in computer technology. You should be aware of your company's policies and practices. In addition, you may need to familiarize yourself with your state or country's trademark and copyright laws. · The call center is a fast-paced environment. Level-one technicians and level-two technicians each have specific responsibilities. These responsibilities may vary slightly from one call center to another. Chapter 11 Notes · USB 1.1 – Transfers data at a maximum speed of 12 Mbps · USB 2.0 – Transfers data at a maximum speed of 480 Mbps · FireWire – (IEEE 1394) – Transfers data at 100, 200, or 400 Mbps and IEEE 1394b at 800 Mbps · Parallel (IEEE 1284) – Transfers data at a maximum speed of 3 MBps · Serial (RS-232) – Early versions were limited to 20 Kbps, but newer versions can reach transfer rates of 1.5 Mbps · SCSI (Ultra-320 SCSI) – Connects as many as 15 devices with a transfer rate of 320 MBps RAID: redundant array of independent disks · CPU and cooling system – Examine the CPU and cooling system for dust buildup. Make sure that the fan can spin freely. Check that the fan power cable is secure, as shown in Figure 1. Check the fan while the power is on to see the fan turn. Inspect the CPU to be sure that it is seated securely in the socket. Make sure that the heat sink is well attached. To avoid damage, do not remove the CPU for cleaning. · RAM connections – The RAM chips should be seated securely in the RAM slots. Figure 2 shows that sometimes the retaining clips can loosen. Reseat them, if necessary. Use compressed air to remove any dust. · Storage devices – Inspect all storage devices including the hard drives, floppy drive, optical drives, and tape drive. All cables should be firmly connected. Check for loose, missing, or incorrectly set jumpers, as shown in Figure 3. A drive should not produce rattling, knocking, or grinding sounds. Read the manufacturer's manual to learn how to clean optical drive and tape heads by using cotton swabs and compressed air. Clean floppy drives with a drive cleaning kit. · Adapter cards – Adapter cards should be seated properly in their expansion slots. Loose cards, as shown in Figure 4, can cause short circuits. Secure adapter cards with the retaining screw to avoid the cards coming loose in their expansion slots. Use compressed air to remove any dirt or dust on the adapter cards or the expansion slots. The first step in the troubleshooting process is to gather data from the customer. Once you have talked to the customer, you should verify the obvious issues. After the obvious issues have been verified, try some quick solutions. If quick solutions did not correct the problem, it is time to gather data from the computer. At this point, you have enough information to evaluate the problem, research, and implement possible solutions. After you have solved the problem, close with the customer. Chapter 12 Notes · Http: Hypertext Transport Protocol: defines how files are exchanged on the web · FTP: File Transfer Protocol: Provides services for file transfer and manipulation · POP: Post Office Protocol: Retrieves e-mail messages from an e-mail server · DNS: Domain Name Services: Resolves URLs for websites with their IP addresses · DHCP: Dynamic Host Control Protocol: Automates assignment of IP addresses Chapter 14 Notes Page Description Language (PDL) A page description language (PDL) is a type of code that describes the appearance of a document in a language that a printer can understand. The PDL for a page includes the text, graphics, and formatting information. Software applications use PDLs to send What You See Is What You Get (WYSIWYG) images to the printer. The printer translates the PDL file so that whatever is on the computer screen is what is printed. PDLs speed up the printing process by sending large amounts of data at one time. They also manage the computer fonts. There are three common PDLs: · Printer Command Language (PCL) – Hewlett-Packard developed PCL for communication with early inkjet printers. PCL is now an industry standard for nearly all printer types. · PostScript (PS) – Adobe Systems developed PS to allow fonts or text types to share the same characteristics on the screen as on paper. · Graphics Device Interface (GDI) – GDI is a Windows component to manage how graphical images are transmitted to output devices. GDI works by converting images to a bitmap that uses the computer instead of the printer to transfer the images. Test the driver. To test the driver, choose Start > Settings > Printers and Faxes in Windows 2000 or Start > Control Panel > Printers and Faxes in Windows XP. Right-click the printer and choose Properties. Then choose Print Test Page. If the printer does not work, restart the computer and then try again. To change the configuration of a global printer, choose Start > Control Panel > Printers and Faxes and right-click the printer. In the Printers folder, right-click the printer to share, select Properties, and click the Sharing tab. Select Share this printer option and assign the printer a name. Network Print Server Devices Network print server devices allow many users on a network to access a single printer. A network print server device can manage network printing through either wired or wireless connections. Figure 1 shows a wired print server. You should consider the advantages and disadvantages of a dedicated PC print server before you install one: · An advantage of using a network print server is that the server accepts incoming print jobs from computers, and then frees the computers for other tasks. The print server is always available to the users, unlike a printer shared from a user's computer. · A disadvantage of a network print server is that it may not be able to use all of the functions of an all-inoon device. Dedicated PC Print Servers A dedicated PC print server is a computer dedicated to handling client print jobs in the most efficient manner. Since it handles requests from multiple clients, a print server is usually one of the most powerful computers on the network. Dedicated PC print servers can manage more than one printer at a time. A print server needs to have resources available to meet the requests of print clients: · Powerful processor – Because the PC print server uses its processor to manage and route printing information, it needs to be fast enough to handle all incoming requests. · Adequate hard disk space – A PC print server captures print jobs from clients, places them in a print queue, and sends them to the printer in a timely way. This requires the computer to have enough storage space to hold these jobs until completed. · Adequate memory – The server processor and RAM handle sending print jobs to a printer. If server memory is not large enough to handle an entire print job, the hard drive must send the job, which is much slower. Computer-shared Printers A user's computer that has a printer attached can share that printer with other users on the network. Windows XP makes the process fast and easy. In a home network, it means users can print documents from wherever they are in the house by using a wireless laptop. In a small office network, sharing a printer means one printer can serve many users. To configure the computer with the printer attached to accept print jobs from other network users, follow these steps: 1. Choose Start > Control Panel > Printers and Other Hardware > Printers and Faxes. 2. Select the printer you want to share. 3. The Printer Tasks box will appear on the left. Select Share this printer. 4. The Printer Properties dialog box for that printer will display. Select the Sharing tab. Select Share this printer and enter the desired share name. This is the name that the printer will appear as to other users. 5. Verify that sharing has been successful. Return to the Printers and Faxes folder and notice that the printer icon now has a hand under it, as shown in Figure 1. This shows that the printer is now a shared resource. Connecting Other Users Other users on the network can now connect to this printer by following these steps: 1. Choose Start > Control Panel > Printers and other Hardware > Add a Printer. 2. The Add Printer wizard appears. Click Next. 3. Select A network printer, or a printer attached to another computer, as shown in Figure 2. Click Next. 4. Type in the name of the printer, or browse for it on the network using the Next button. A list of shared printers will appear. 5. After you select the printer, a virtual printer port is created and displayed in the Add a Printer window. The required print drivers are downloaded from the print server and installed on the computer. The wizard then finishes the installation. Installing Printer Memory The first step in installing additional printer memory is to read the printer manual to determine the following: · Memory type – Physical type of memory, speed, and capacity; some are standard types of memory, whereas others require special or proprietary memory · Memory population and availability – Number of memory upgrade slots in use, and how many available; this may require opening a compartment to check RAM These are the most common types of scanner options: · Resizing · Sharpening · Brightening or darkening · Color correction · Resolution changes · Output file format · Color inversion If a scanner does not produce output in a file format required by the customer, the format can be converted later using software tools. After changing device settings, you should test the changes by making some sample printouts. For laser printers, the kit may contain replacement parts that often break or wear out: · Fuser assembly · Transfer rollers · Separation pads · Pickup rollers Each time you install new parts or replace toners and cartridges, do a visual inspection of all the internal components: · Remove bits of paper and dust · Clean spilled ink · Look for any worn gears, cracked plastic, or broken parts · Print heads in an inkjet printer are replaced when the cartridges are replaced. However, sometimes print heads become clogged and require cleaning. Use the utility supplied by the manufacturer to clean the print heads. After you clean them, you should test them. Repeat this process until the test shows a clean and uniform print. Printers have many moving parts. Over time, the parts collect dust, dirt, and other debris. If not cleaned regularly, the printer may not work well, or could stop working completely. When working with dot matrix printers, clean the roller surfaces with a damp cloth. On inkjet printers, clean the paper-handling machinery with a damp cloth. When cleaning a laser printer, use a specially designed vacuum cleaner to pick up toner particles. Figure 1 shows a vacuum designed for electronic equipment. A standard vacuum cleaner cannot hold the tiny particles of toner and may scatter them about. Use only a vacuum cleaner with HEPA filtration. HEPA filtration catches microscopic particles within the filters. Choosing the correct paper type for a printer helps the printer last longer and print more efficiently. Several types of paper are available. Each type of paper is clearly labeled with the type of printer for which it is intended. The manufacturer of the printer may also recommend the best type of paper. Check the printer manual. Information about the brands and types of ink recommended by the manufacturer is also found in the manual. Using the wrong type of ink may cause the printer not to work or may reduce the print quality. To prevent ink leaks, do not refill ink cartridges. Scanner Maintenance You should clean scanners regularly to prevent dirt, fingerprints, and other smudges from showing in scanned images. On flatbed scanners, keep the lid closed when the scanner is not in use. This will help to prevent dust build-up and accidental fingertip smudges. If the glass becomes dirty, consult the user guide for the manufacturer's cleaning recommendations. If the manual does not list any recommendations, use a glass cleaner and a soft cloth to protect the glass from scratching. Even very small scratches can be visible on high-resolution scans. If dirt becomes lodged in the scratches, the scratches will become more visible. If the inside of the glass becomes dirty, check the manual for instructions on how to open the unit or remove the glass from the scanner. If possible, thoroughly clean both sides and replace the glass as it was originally installed in the scannerYou can set the printer software to reduce the amount of ink or toner that the printer uses. This setting may be called "toner save" or "draft quality". This setting reduces the print quality of laser and inkjet products, and reduces the time it takes to print a document on an inkjet printer. Most inkjet printers provide a utility that shows ink levels in each cartridge, as shown in Figure 1. Some printers have LCD message screens or LED lights that warn users when ink supplies are low. Always follow safety procedures when working with printers and scanners. There are many parts inside printers that contain high voltage or become very hot with use. Use the device manual and software to install a printer or scanner. After the installation, update the drivers and firmware to fix problems and increase functionality. Use the Windows interface to share printers and scanners across the network. Consult the customers to determine how best to upgrade and configure printers and scanners to meet their needs. Keep printers, scanners, and supplies clean and dry. Keep supplies in their original packaging to prevent breakdowns and downtime. Develop a maintenance schedule to clean and check devices on a regular basis. Use a sequence of steps to fix a problem. Start with simple tasks before you decide on a course of action. Call a qualified or certified printer technician when a problem is too difficult for you to fix. Chapter 15 Notes · The TCP/IP suite of protocols is required for every device to connect to the Internet. This makes it a preferred protocol for networking. · NetBEUI is a small, fast protocol that is useful in low security networks. NetBEUI performs well in a small network that is not connected to the Internet. It is easy to install and requires no configuration. However, NetBEUI can cause unnecessary traffic on a large network, so it is not a good choice if there will be network growth. · IPX/SPX is a protocol that belongs to older versions of Novell Netware. Because of the growth of the Internet, newer versions of Novell Netware use TCP/IP instead of IPX/SPX. · Apple Macintosh networks have abandoned the AppleTalk protocol for the TCP/IP suite of protocols to ensure connectivity with other TCP/IP networks, most notably the Internet. Select the cable type that is the most beneficial and cost effective for the users and services that will connect to the network. Cable Types The size of the network determines the type of network cable that will be used. Most networks today are wired using one or more kinds of types of twisted-pair copper cable: · Cat5 · Cat5e · Cat6 · Cat6A Cat5 and Cat5e cables look the same, but Cat 5e cable is manufactured with a higher standard to allow for higher data transfer rates. Cat6 cable is constructed with even higher standards than Cat5e. Cat6 cable may have a center divider to separate the pairs inside the cable. Cat6A cable carries Ethernet signals at a rate of 10 Gbps. The abbreviation for 10 GB Ethernet over twisted-pair cable is 10GBase-T, as defined in the IEEE 802.3an-2006 standard. Customers who need high bandwidth networks can benefit from installing cable that can support Gigabit Ethernet or 10 GB EthernetNew or renovated office buildings often have some type of UTP cabling that connects every office to a central point called the Main Distribution Facility (MDF). The distance limitation of UTP cabling used for data is 330 feet (100 m). Network devices that are farther than this distance limitation need a repeater or hub to extend the connection to the MDF. Cost When designing a network, cost is a consideration. Installing cables is expensive, but after a one-time expense, a wired network is normally inexpensive to maintain. Most of the devices on a wired network cost much less than the devices on a wireless network. Security A wired network is usually more secure than a wireless network. The cables in a wired network are usually installed in walls and ceilings, and therefore not easily accessible. Wireless is easier to eavesdrop. The signals are available to anyone who has a receiver. To make a wireless network as secure as a wired network requires the use of encryption. Design for the Future Many organizations install the highest grade cable available to ensure that their networks can handle the network speeds that will be available in the future. The organizations want to avoid having to do expensive reinstalling of cable later. You and your customer must decide if the cost of installing a higher grade cable is necessary. Wireless A wireless solution may be possible in places where cables cannot be installed. Consider an older, historic building where local building codes do not permit structural modifications. In this case, installing cable is not possible and therefore a wireless connection is the only solution. There are three main considerations for an Internet connection: · Speed · Reliability · Availability POTS A plain old telephone system (POTS) connection is extremely slow but it is available wherever there is a telephone. The modem uses the telephone line to transmit and receive data. ISDN The Integrated Services Digital Network (ISDN) offers faster connection times and has faster speeds than dial-up, and allows multiple devices to share a single telephone line. ISDN is very reliable because it uses POTS lines. ISDN is available in most places where the telephone company supports digital signaling. DSL Digital Subscriber Line (DSL), like ISDN, allows multiple devices to share a single telephone line. DSL speeds are generally higher than ISDN. DSL allows the use of high-bandwidth applications or multiple users to share the same connection to the Internet. In most cases, the copper wires already in your home or business are capable of carrying the signals needed for DSL communication. Cable Cable Internet connection does not use telephone lines. Cable uses coaxial cable lines originally designed to carry cable television. Like DSL, cable offers high speeds and an "always-on" connection, which means that even when the connection is not in use, the connection to the Internet is still available. Many cable companies offer telephone service as well. Satellite For people that live in rural areas, broadband satellite Internet connections provide a high-speed connection that is always on. A satellite dish is used to transmit and receive signals to and from a satellite that relays these signals back to a service provider. Wireless Many types of wireless Internet services are available. The same companies that offer cellular service may offer Internet service. PCMCIA and PCI cards are used to connect a computer to the Internet. The service is not available in all areas.· If you have a 10/100 Mbps NIC and a hub that is only 10 Mbps, the NIC will operate at 10 Mbps. · If you have a 10/100/1000 Mbps NIC and a switch that is only operating at 100 Mbps, the NIC will operate at 100 Mbps. · Most network interfaces for desktop computers are either integrated into the motherboard or are an expansion card that fits into an expansion slot. · Most laptop network interfaces are either integrated into the motherboard or fit into a PC Card or Express Bus expansion slot. · USB network adapters plug into any available USB port and can be used with both desktops and laptops. · 802.11b NICs can be used on 802.11g networks. · 802.11a can be used only on a network that supports 802.11a. · 802.11a, 802.11b and 802.11g NICs can be used on 802.11n networks. Hubs A hub is used to share data between multiple devices on a section of the network. The hub may connect to another networking device like a switch or router that connects to other sections of the network. The maximum speed of the network is determined by the speed of the hub. Switches In modern networks, switches have replaced hubs as the central point of connectivity. Like a hub, the speed of the switch determines the maximum speed of the network. However, switches filter and segment network traffic by sending data only to the device to which it is sent. This provides higher dedicated bandwidth to each device on the network. Routers Routers connect networks together. On a corporate network, one router port connects to the WAN connection and the other ports connect to the corporate LANs. The router becomes the gateway, or path to the outside, for the LAN. In a home network, the router connects the computers and network devices in the home to the Internet. In this case, the router is a home gateway. The wireless router, shown in Figure 1, serves as a firewall and provides wireless connectivity. When the home router provides multiple services, it may be called a multifunction device. ISP Equipment When subscribing to an ISP, you should find out what type of equipment is available so that you can select the most appropriate device. Many ISPs offer a discount on equipment that is purchased at the time of installation. These steps outline the process for physically creating a network: 1. To install the cable in ceilings and behind walls, you perform a cable pull. One person pulls the cable, and the other feeds the cable through the walls. Make sure to label the ends of every cable. Follow a labeling scheme that is already in place, or follow the guidelines outlined in TIA/EIA 606-A. 2. After the cables have been terminated on both ends, you should test them to make sure there are no shorts or interference. 3. Make sure that network interfaces are properly installed in the desktops, laptops, and network printers. After the network interfaces have been installed, configure the client software and the IP address information on all of the devices. 4. Install switches and routers in a secured, centralized location. All of the LAN connections terminate in this area. In a home network, you may need to install these devices in separate locations, or you may have only one device. 5. Install an Ethernet patch cable from the wall connection to each network device. Check to see if you have a link light on all network interfaces. In a home network, make sure that each network device port that connects to a device is lit. 6. When all devices are connected and all link lights are functioning, you should test the network for connectivity. Use the ipconfig /all command to view the IP configuration on each workstation. Use the ping command to test basic connectivity. You should be able to ping other computers on the network, including the default gateway and remote computers. Once you have confirmed basic connectivity, you must configure and test network applications such as e-mail and an Internet browser. Temporary Internet Files When an operating system such as Windows XP has been installed, IE is also installed by default. With IE, every time that you visit a website, many files are downloaded to your computer in the Temporary Internet Files folder. Most of these files are image files that represent banners and other components of the website. Default Browser You can confirm which browser Windows uses by default. Choose Start > Run, enter a website address, and click OK. The website opens in the browser that is currently set as the default. File Sharing Users can share resources over the network. You can share a single file, specific folders, or an entire drive, as shown in Figure 2. To share a file, you should first copy it to a folder. Right-click the folder and select Sharing and Security. Next select Share this folder. You can identify who has access to the folder and what permissions they have on the objects in the folder. Figure 3 shows the permissions window of a shared folder. Permissions define the type of access a user has to a file or folder: · Read – Allows the user to view the file and subfolder names, navigate to subfolders, view data in files, and run program files. · Change – Allows all of the permissions of the Read permission but allows the user to add files and subfolders change the data in files, and deletes subfolders and files. · Full Control – Allows all of the permissions of Change and Read. If the file or folder is in an NTFS partition, Full Control allows you to change permissions on the file or folder, and take ownership of the file or folder. Windows XP Professional is limited to a maximum of 10 simultaneous file-sharing connections. Printer Sharing To share a printer, select Start > Control Panel > Printers and Faxes. Right-click the printer icon and select Sharing. Click Share this Printer and then click OK. The printer is now available for other computers to access. To access a printer shared by another computer, select Start > Control Panel > Printers and Faxes. Click File > Add Printer. Use the Add Printers wizard to find and install the shared network printer.1. Use a floor plan to find the locations for access points that allow maximum coverage. The best place for a wireless access point is at the center of the area you are covering, with a line of sight between the wireless devices and the access point. 2. Connect the access point to the existing network. On the back of the Linksys WRT300N router, there are five ports. Connect a DSL or cable modem to the port labeled "Internet". The switching logic of the device forwards all of the packets through this port when there is communication to and from the Internet and other connected computers. Connect one computer to any of the remaining ports to access the configuration web pages. 3. Turn on the broadband modem and plug in the power cord to the router. When the modem finishes establishing connection to the ISP, the router automatically communicates with the modem to receive network information from the ISP that is necessary to gain access to the Internet: IP address, subnet mask, and DNS server addresses. 4. When the router has established communication with the modem, you must configure the router to communicate with the devices on the network. Turn on the computer that is connected to the router. Open a web browser. In the Address field, enter 192.168.1.1. This is the default address for router configuration and management. 5. A security window prompts you for authentication to access the router configuration screens. The user name field should be left empty. Enter admin as the default password. When logged in, the first setup screen opens. 6. Continue with the setup. There are tabs that have sub-tabs on the setup screen. You must click Save Settings at the bottom of each screen after making any changes. Network Connections To verify a wireless connection using the Windows XP GUI, select Start > Control Panel > Network Connections, as shown in Figure 1. Double-click on the wireless network connection to display the status. The Connection Status screen shown in Figure 2 displays the number of packets that have been sent and received. The packets are the communication between the computer and the network device. The window shows whether or not the computer is connected, along with the speed and duration of the connection. To display the Address Type, as shown in Figure 3, choose the Support tab on the Connection Status screen. The Connection Status information includes either a static address, which is assigned manually, or a dynamic address which is assigned by a DHCP server. The subnet mask and default gateway are also listed. To access the MAC address and other information about the IP address, click Details.... If the connection is not functioning correctly, click Repair to reset the connection information and attempt to establish a new connection. Ipconfig The ipconfig command is a command line tool that is used to verify that the connection has a valid IP address. The window displays basic IP address information for network connections. To perform specific tasks, add switches to the ipconfig command, as shown in Figure 4. Ping Ping is a CLI tool used to test connectivity between devices. You can test your own connection by pinging your computer. To test your computer, ping your NIC. Select Start > Run > cmd. At the command prompt, enter ping local host. This command lets you know if your adapter is working properly. Ping your default gateway to check if your WAN connection is working properly. You can find the address for the default gateway by using the ipconfig command. To test the Internet connection and DNS, ping a popular website. Select Start > Run > cmd. At the command prompt, enter ping destination name. The response of the ping command displays the IP address resolution of the domain. The response shows replies from the ping or that the request timed out because there is a problem.Tracert Tracert is a CLI tool that traces the route that packets take from your computer to a destination address. Select Start > Run > cmd. At the command prompt, enter tracert. E-mail Server An e-mail server is a computer that can send and receive e-mail on behalf of e-mail clients. These are some common e-mail servers: · Microsoft Exchange · Send mail · Eudora Internet Mail Server (EIMS) E-mail Server Installation You should test the environment before you install Exchange. To prevent the installation from affecting the daily operation of your network, set up the services required and install Exchange on a dedicated set of servers away from the main network. Keep the installation of Exchange separated from your production network until you are sure that it is functioning properly. Before you install Exchange, be prepared with the proper equipment and information: · Fully functional and reliable DNS deployment · Active Directory domain · At least one Global Catalog · Windows 2000 or higher native domain functionality · Exchange server software · Windows server support tools · Schema master server · High-speed Internet connection