CompTIA A+ Studying Part 1

An application uses Transmission Control Protocol (TCP) as it requires data to make it to the destination 100% intact. Which of the following are functions of this protocol? (Select all that apply.) A. Uses SYN/ACK packets. B. Uses TFTP. C. Uses negative acknowledgment. D. Uses FIN.

A. Uses SYN/ACK packets. C. Uses negative acknowledgment. D. Uses FIN. Because TCP establishes a connection between the sender and recipient using a handshake sequence of SYN, SYN/ACK, and ACK packets. TCP allows the receiver to send a negative acknowledgment (NACK) to force retransmission of a missing or damaged packet. TCP allows the graceful termination of a session using a FIN handshake. The main drawback is that this connection information requires multiple header fields. Network devices typically use Trivial File Transfer Protocol (TFTP) to obtain a configuration file. The application protocol uses its own acknowledgment messaging, so it does not require TCP.

A technician must determine why a computer is overheating. Which of the following may be the cause? (Select all that apply.) A.Blanking plates are covering holes. B. A fan is not working. C. The area is too warm. D. There is an invalid cable specification

B. A fan is not working. C. The area is too warm. Because A computer can overheat because a fan is not working. Proper cooling is vital to the lifespan and performance of the processor. A computer can overheat because an area is too warm. The technician should check whether the PC is near a hot radiator or in direct sunlight. A technician should always use blanking plates to cover up holes in the back or front of the PC. Holes can disrupt the airflow and decrease the effectiveness of the cooling systems. An invalid cable specification can cause display issues. If the display is on and the technician can rule out a problem with the input source, they should check the cable.

A technician started a PC and, when the vendor's logo came up, pressed the F10 key. What is the technician doing? A. Restarting the PC B. Accessing the system setup program C. Setting a boot password D. Enabling secure boot

B. Accessing the system setup program Because The technician is accessing the system setup program via a keystroke during the power-on (boot) process when the PC vendor's logo displays. A technician can restart a computer to access the unified extensible firmware interface (UEFI) boot options by shift-clicking the restart button from the Windows logon screen. A boot password requires the user to authenticate before the operating system loads. However, everyone who uses the PC must know the password, which weakens the security considerably. Secure boot is a UEFI feature designed to protect a computer from malware. Under secure boot, the computer firmware has cryptographic keys that can identify trusted code.

A support technician needs to connect the USB port on a portable monitor to an HDMI port on a laptop to extend the laptop's display. What kind of cable will the technician use to accomplish this? A. SCSI B. Adapter C. EIDE D. DVI

B. Adapter Because The technician will use an adapter cable to connect the HDMI port on the laptop with a USB port on the monitor. An adapter cable has connectors for two different cable types at each end. A small computer system interface (SCSI) can connect both internal devices and external peripherals, such as scanners and printers, but must enable termination on the first and last devices in the chain. An extended integrated drive electronics (EIDE) cable typically has three color-coded connectors and was the principal mass storage interface for desktop PCs for many years. A digital visual interface (DVI) supports both analog and digital outputs. DVI is likely to be encountered on older display devices and video cards.

A technician is upgrading the system firmware on a PC. Which of the following is the technician upgrading? (Select all that apply.) A. System settings B. BIOS C. Secure boot D. UEFI

B. BIOS D. UEFI Because The technician is upgrading the basic input/output system (BIOS) which is the system firmware for a PC that only supports 32-bit operation and limited functionality. The technician is upgrading the unified extensible firmware interface (UEFI) which provides support for 64-bit CPU operation at boot and many other functions. Technicians configure system settings via the system firmware setup program. A keystroke accesses the system setup program during the power-on (boot) process. Secure boot is a UEFI feature designed to protect a computer from malware. Under secure boot, the computer firmware has cryptographic keys that can identify trusted code.

A computer is processing software instructions on the central processing unit. How is all computer software broken down to be processed? A. Bus B. Binary C. RAM D. System clock

B. Binary Because All computer software works by running instructions in the central processing unit (CPU) and computers process all the software and data as the ones and zeroes of binary code. Bus interfaces on the motherboard transmit instructions and data between computer components using electrical signals. Many types of bus interfaces can supply power to the connected components. Random access memory (RAM) storage technology is non-persistent which means that the RAM devices can only hold data when a user powers on the PC. The motherboard's system clock synchronizes the operation of all parts of the PC and provides the basic timing signal for the CPU. PCs measure clock speeds in Megahertz (MHz) or Gigahertz (GHz).

A hardware technician is reinstalling a heat sink with a central processing unit (CPU). Which of the following steps should the technician take to reinstall the heat sink? (Select all that apply.) A. Clean it. B. Thermal paste. C. Pop up the CPU at a 45º angle. D. Wear an ESD wrist strap.

A. Clean it. B. Thermal paste. D. Wear an ESD wrist strap. Because If reinstalling the same heat sink, the hardware technician should clean old thermal grease from the surfaces of the heat sink. When installing a heat sink, the hardware technician should apply a small amount of new grease in an X pattern. The technician should not apply too much—if it overruns, the excess could damage the socket. The technician should take anti-electrostatic discharge (ESD) precautions, such as wearing an ESD wrist strap, when handling and storing CPUs. Laptop RAM is in a smaller form factor called small outline DIMM (SODIMM). The memory fits into slots that pop up at a 45º angle to allow the technician to insert or remove the chips.

A desktop technician just fixed an issue where a computer would not connect to a network and verified the computer is communicating with the network again. What should the technician do now that will help with future troubleshooting efforts? A. Document findings. B. Test the theory. C. Establish a plan of action. D. Refer to vendor instructions.

A. Document findings. Because The technician should document the findings which is very useful for future troubleshooting. Technicians can see if the same solution applies to future problems fitting into the same category. After the technician has established a theory about an issue, they will test the theory to see if it corrects and resolves the issue. After a technician has determined the best solution to an issue, they must devise a plan of action to put the solution in place and assess the resources, time, and cost required. If a technician is completing troubleshooting steps under instruction from the vendor's support service, they must make sure they properly understand the steps they are taking.

A hardware technician is building a server that will process financial data in real-time and wants to use error correcting code (ECC) RAM that will detect and correct errors, if possible. What other considerations will the technician need to include to support the ECC RAM? (Select all that apply.) A. ECC - Capable Motherboard B. 72-bit data bus C. DDR memory module D. Two 64-bit data buses

A. ECC - Capable Motherboard B. 72-bit data bus Because The motherboard must have a memory controller that is capable of supporting ECC RAM. The technician will need to include a 72-bit data bus rather than the regular 64 bits to support the functions of the ECC RAM in the server. DDR memory modules, or DIMMs, typically feature heat sinks, due to the use of high clock speeds, but that is not relevant to supporting ECC RAM in a server. A dual-channel memory controller has two 64-bit pathways through the bus to the central processing unit (CPU), meaning that each transfer can send 128 bits of data.

A desktop technician was troubleshooting a computer that would not connect to the network and suspected that the network interface card (NIC) was not working. However, when the technician tested the NIC, it was working. What will the technician do next? A. Establish a new theory. B. Implement a plan of action. C. Test the theory. D. Implement preventive measures.

A. Establish a new theory. Because The technician would establish a new theory as the tests they made or research they conducted proved that their original theory was incorrect. Once the technician had a reliable theory of probable cause, then they would need to implement a plan of action by repairing or replacing the equipment or implementing a workaround. The technician cannot test the theory until after they have established a new theory about why the computer cannot connect to the network. The technician would implement preventive measures after they corrected the issue. This means eliminating any factors that could cause the problem to reoccur.

A network technician troubleshoots a computer that is getting a limited connectivity message and an address in the automatic IP addressing (APIPA) 169.254.x.y range instead of receiving a lease for an IP configuration from the DHCP server. What are some steps the technician should take to troubleshoot this issue? (Select all that apply.) A. Establish the scope of the issue. B. Check the configuration of patch cords. C. Check the VLAN configuration. D. Sample the elapsed time between arriving packets.

A. Establish the scope of the issue. B. Check the configuration of patch cords. C. Check the VLAN configuration. Becuase The technician should establish the scope of the issue. If the issue affects multiple users, the problem is likely to be the Dynamic Host Configuration Protocol (DHCP) server itself. The technician should check the configuration of the patch cords and verify that the wall port connects to an appropriate port on a switch via the patch panel. The technician should check the virtual LAN (VLAN) configuration. If the switch port does not have the correct VLAN ID, it can have the same effect as connecting the host to the wrong switch port. Sampling the elapsed time between arriving packets is a method the technician would use to test for jitter in a voice over IP network.

A support technician is installing a PCIe card that will use a combination of system memory and dedicated memory. What type of card is the tech installing? A. Graphics B. Sound C. NIC D. Wi-Fi

A. Graphics Because The support technician is installing a graphics adapter, also called a video card. Graphics adapters can have up to 12 GB of dedicated memory and may use a mix of dedicated and shared, or system, memory. Sound cards provide audio playback through speakers or headphones which plug into the card via an audio jack and sound cards also record input from a microphone. Network interface cards (NICs) usually come already installed as part of the motherboard chipset, but a technician may need to upgrade it to use a different type of network or cabling or connector. Technicians can add a Wi-Fi adapter to connect to a wireless network. Manufacturers develop Wi-Fi adapters to different 802.11 standards.

A hardware technician is scanning a computer's non-volatile storage devices for errors and infections. Which of the following will the technician include in the scanning? (Select all that apply.) A. Hard disk drives B. Solid-state drives C. Random access memory D. Mass storage devices

A. Hard disk drives B. Solid-state drives D. Mass storage devices Because The technician will include hard disk drives in their scanning. Hard disk drives are non-volatile storage that store data on metal or glass platters coated with a magnetic substance. The technician will include solid-state drives in their scanning. Solid-state drives are non-volatile storage that use flash memory technology to implement persistent mass storage. Non-volatile storage devices, or mass storage devices, hold data when the system is off. Mass storage devices use magnetic, optical, or solid-state technology to store data. Random-access memory (RAM) storage technology is nonpersistent. Nonpersistent means that the RAM devices can only hold data when the PC is on.

A support technician opened a PC case and observed a small computer system interface (SCSI) connector plugged into the motherboard. What can the technician know to be true about the connector? A. It is likely connected to the hard disk. B. Each device on a wide SCSI bus must be configured with a unique ID, from 0 to 68. C. It transfers data 1 bit at a time. D. It only supports 1 device at a time.

A. It is likely connected to the hard disk. Because SCSI connectors are commonly used to connect hard disks, as well as other storage devices like tape drives, CD/DVD drives, and external storage devices. Each device on a wide SCSI bus must be configured with a unique ID, from 0 to 15. While a serial interface essentially transfers 1 bit at a time, a parallel interface such as SCSI transfers 8 bits (1 byte) or more and requires more wires in the cable and more pins in the connectors. One SCSI host bus adapter (HBA) can control multiple devices attached by internal ribbon cables or external SCSI cables.

A network technician troubleshoots an issue where the video conferencing system keeps freezing up and dropping out. The technician determines that the router is not processing the signal fast enough. What is this type of issue known as? A. Latency B. VoIP C. QoS D. Jitter

A. Latency Because This issue is known as latency which is the time it takes for a signal to reach the recipient. Processing delays at intermediate systems, such as routers, can cause latency to be worse. Voice over Internet Protocol (VoIP) is a generic name for protocols that carry voice traffic over data networks. Quality of service (QoS) means that switches, access points, and routers are all configured to identify VoIP data and prioritize it over bursty data. Jitter is the amount of variation in delay over time and network technicians can measure it by sampling the elapsed time between packets arriving.

A hardware technician installed a new power supply unit (PSU) in a workstation and removed any unnecessary power connector cables. What type of PSU did the technician install? A. Modular B. Redundant C. ATX D. ATX12V

A. Modular Because The hardware technician is installing a modular PSU which has detachable power connector cables that allow the technician to reduce the number of cables to the minimum required. A redundant power supply unit, also called a failover power supply unit, is a second power supply unit in a computer system. Advanced Technology Extended (ATX) is the original PSU standard in which the P1 connector is 20-pin (2x10) and wires with black insulation are ground, yellow are +12 V, red are +5 V, and orange are +3.3 V. ATX12V is the version 2 PSU standard which defines a 24-pin (2x12) P1 form factor to replace the 20-pin one.

A network technician uses a switch configuration interface and sees that a port is continually transitioning between up and down states. What does the network technician witness? A. Port flapping B. Slow network speeds C. RSSI D. QoS

A. Port flapping Because Port flapping is when the network interface card (NIC) or switch interface transitions continually between up and down states. Bad cabling, external interference, or a faulty NIC at the host end can cause this to happen. There are a variety of problems that can cause slow network speeds and they can be difficult to diagnose. A technician should apply a structured process to investigate possible causes. The received signal strength indicator (RSSI) is the signal strength as measured at the receiver, using either decibel units or an index value. Quality of service (QoS) means that switches, access points, and routers are all configured to identify voice over internet protocol (VoIP) data and prioritize it over bursty data.

A desktop technician determined that a computer could not connect to the network because the network drop was not working. What possibilities are open to the technician for getting the computer back on the network? (Select all that apply.) A. Repair the drop. B. Implement preventive measures. C. Replace the drop. D. Implement a workaround.

A. Repair the drop. C. Replace the drop. D. Implement a workaround. Because A possibility that is open to the technician is to repair the drop. The technician needs to determine whether the cost of repair makes this the best option. A possibility that is open to the technician is to replace the drop. This option is often more expensive and may be time-consuming if a part is not available. A possibility that is open to the technician is to implement a workaround. If neither repair nor replacement is cost-effective, it may be best to find a workaround. Implementing preventive measures means eliminating any factors that could cause the problem to reoccur.

All the employees in a lawyer's office communicate with the internet and each other through the same appliance. What kind of network is the office using? A. SOHO B. Zigbee C. PAN D. MAN

A. SOHO Because The office uses a small office home office (SOHO) LAN, which is a business-oriented network using a single networking appliance to provide LAN and internet connectivity. The Zigbee protocol is designed for operation on low-power devices without substantial CPU or storage resource. Zigbee is a wireless mesh networking protocol. A personal area network (PAN) is a group of devices connected wirelessly, such as by Bluetooth. A metropolitan area network (MAN) refers to a specific network type covering an area equivalent to a city or other municipality.

A network technician needs to deploy a computer on an Ethernet network and notices that the computer will sit on a shelf directly under a fluorescent light. What type of cable will the technician use? A. STP B. UTP C. Coax D. Fiber optic

A. STP Because The technician will use shielded twisted pair (STP) which provides extra protection against interferences in environments with high levels of external interference, such as fluorescent lighting. Unshielded twisted pair (UTP) contains four copper conductor wire pairs each twisted at a different rate from the other pairs which reduces interference. Coaxial (coax) cable is a different type of copper cabling that also carries electrical signals. Technicians mostly use it for CCTV installations, Cable Access TV (CATV), and broadband cable modems. Fiber optic cable consists of an ultra-fine core of glass that conveys light pulses. The core is inside of glass or plastic cladding, which guides the light pulses along the core.

A hardware technician is inspecting the notches on a dual inline memory module (DIMM) edge. What will the notches on the edge connector help the hardware technician determine? (Select all that apply.) A. The DDR generation B. If it is compatible with the slot C. How to insert it properly D. If it has a heat sink

A. The DDR generation B. If it is compatible with the slot C. How to insert it properly Because The notches on a DIMM's edge connector help the hardware technician identify the double data rate (DDR) generation (DDR3/DDR4/DDR5). The notches on a DIMM's edge connector help prevent the hardware technician from inserting the DIMM into an incompatible slot. The notches on a DIMM's edge connector help prevent the hardware technician from inserting the DIMM into a slot the wrong way around. DDR memory modules, or DIMMs, typically feature heat sinks, due to the use of high clock speeds but that is not relevant to the notches on the DIMM's edge connector.

A support technician manages digital displays but has some older computers with video cards that can support both analog and digital monitors. What type of video interface do these older computers have? A. HDMI B. DVI C. VGA D. DisplayPort

B. DVI Because The older computers have a digital visual interface (DVI) that supports both analog and digital outputs. DVI is no longer in active development and is only on older display devices and video cards. The high-definition multimedia interface (HDMI) video interfaces only support digital displays. Older video interfaces, such as VGA, supported computer monitors driven by an analog signal. The 15-pin video graphics array (VGA) port was the standard analog video interface for PC devices for a very long time, though it is starting to be phased out completely now. DisplayPort video interfaces only support digital displays. Older video interfaces, like DVI, supported computer monitors and projectors that were predominantly of the cathode ray tube (CRT) type.

Every time a user attempts to save a file, the computer shows an error that reads, "Cannot read from the source disk." What kind of issue does this indicate? A. POST issue B. Drive issue C. Power issue D. RAID failure

B. Drive issue Because A "cannot read from the source disk" error indicates an issue with a fixed disk drive that is failing. Bad sectors typically cause this on a hard disk drive. Power-on self-test (POST) is a diagnostic program implemented in the system firmware that checks the hardware to ensure the components required to boot the PC are present and functioning correctly. A power issue might arise due to a fault in the power supply unit (PSU), incoming electricity supply, power cables/connectors, or fuses. In a redundant array of independent disks (RAID), if one of the underlying devices fails, the volume will show up as "degraded," but the data on the volume will still be accessible.

A hardware technician is working on a new desktop that can send 128 bits of data per transfer rather than 64 bits. What is this referred to as? A. Single channel B. Dual channel C. Triple channel D. Quadruple channel

B. Dual channel Because This is a dual channel memory controller as there are effectively two 64-bit pathways through the bus to the central processing unit (CPU) meaning that each transfer can send 128 bits of data. Single-channel memory means that there is one 64-bit data bus between the CPU, memory controller, and random access memory (RAM) devices. In triple channel memory controllers, if the system does not have the full complement of modules, it will revert to the number of populated channels. Some CPUs and supporting chipsets have quadruple channel memory controllers. In this architecture, the system will only use the populated channels.

A network technician is setting static IPv4 addresses on servers. Which settings would be considered optional for ensuring proper communications within a local area network? (Select all that apply.) A. The gateway B. The alternate DNS C. IP address D. Subnet mask

A. The gateway B. The alternate DNS Because The gateway parameter is the IPv4 address of a router and is the IP address to which packets destined for a remote network should go by default. This will be changed for groups of locally connected devices. The Domain Name System (DNS) and alternate DNS servers provide resolution of host and domain names to their IP addresses and are essential for locating resources on the internet. Each host must be configured with an IP address and subnet mask at a minimum to communicate on an IPv4 network. The subnet mask is entered in dotted decimal notation, such as 255.255.255.0. When used with the IP address 192.168.0.100 , this mask identifies 192.168.0.0 as the network ID and means that the last octet ( .100 ) is the host ID.

A network technician is troubleshooting an issue where a wireless device only receives an intermittent signal. What could be a possible cause of this? (Select all that apply.) A. Another radio source is broadcasting at the same frequency. B. There is Wi-Fi analyzer software running. C. There is an electromagnetic source nearby. D. Something is blocking the signal.

A. Another radio source is broadcasting at the same frequency. C. There is an electromagnetic source nearby. D. Something is blocking the signal. Because If a device is within the supported range but the signal is intermittent, there is likely to be interference from another radio source broadcasting at the same frequency. Interference from a powerful electromagnetic source, such as a motor or a microwave oven, can cause an intermittent wireless signal. Radio waves do not pass easily through metal or dense objects. Construction materials, such as wire mesh, foil-backed plasterboard, concrete, and mirrors, can block or degrade signals. Wi-Fi analyzer software identifies the signal strength of nearby networks on each channel. It shows the signal strength with values close to zero representing a stronger signal.

A support technician is installing a new SATA hard drive on a new computer. What is the best type of cable connector the technician will plug in to supply power to the drive? A. 15-pin connector B. 7-pin connector C. 4-pin connector D. USB connector

A. 15-pin connector Because The technician will plug in a 15-pin SATA power connector to connect the hard drive to the PC's power supply. Serial advanced technology attachment (SATA) is the standard means of connecting internal storage drives within a desktop PC. The 7-pin connector is for data and does not supply power to the drive. Legacy storage devices connect to the PC's power supply unit (PSU) via a Molex connector. A Molex connector is usually white or clear plastic and has 4 pins. A USB connector predominantly connects external SATA (eSATA) peripheral drives to an eSATAp port which is a non-standard powered port.

A network technician is upgrading the wireless network so that it can take advantage of "multiple input multiple output" (MIMO) to increase reliability and bandwidth. What standard is the technician upgrading the wireless network to? A. 802.11n B. 802.11g C. 802.11b D. 802.11a

A. 802.11n Because The technician is upgrading the wireless network to 802.11n which uses MIMO to increase reliability and bandwidth by multiplexing signal streams from 2-3 separate antennas. The IEEE 802.11g uses the same encoding mechanism and 54 Mbps rate as 802.11a but in the 2.4 GHz band used by 802.11b and with the same channel layout. The IEEE 802.11b standard uses the 2.4 GHz frequency band, however, the signal encoding methods used by 802.11b are inferior to 802.11a and support a nominal data rate of just 11 Mbps. The IEEE 802.11a standard uses the 5 GHz frequency band only. The data encoding method allows a maximum data rate of 54 Mbps.

A student is learning about computer hardware and the instructor selects them to identify the component that executes program instruction code. How should the student respond? A. CPU B. RAM C. Cache D. HDD

A. CPU Because The student should respond with CPU, or central processing unit. The CPU in a computing device executes the program instruction code. Random access memory (RAM) is a space where the computing device loads applications and files so that users can perform operations on that data. Cache is a small block of memory that works at the speed of the CPU or close to it, depending on the cache level. A hard disk drive (HDD) stores data on metal or glass platters coated with a magnetic substance. The top and bottom of each platter has its own read/write head, moved by an actuator mechanism.

A network technician is checking the records to ensure all the host names match up with the proper IP addresses for the network. What records is the technician checking? (Select all that apply.) A. A B. MX C. FQDN D. AAAA

A. A D. AAAA Because An address (A) record is a resource record that resolves a host name to an IPv4 address. Network technicians can create and update resource records manually (statically). An AAAA record is a resource record on a DNS server that resolves a host name to an IPv6 address. Client and server computers on the network can generate resource records dynamically. A mail exchange (MX) record identifies an email server for the domain so that other servers can send messages to it. A fully qualified domain name (FQDN) is a unique label specified in a DNS hierarchy to identify a particular host within a subdomain within a top-level domain.

A support technician is working on a motherboard that is 12" x 9.6" and has seven expansion slots. Which form factor is the technician working with? A. ATX B. mATX C. SFF D. Mini-ITX

A. ATX Because The Advanced Technology Extended (ATX) specification is the standard form factor for most desktop PC motherboards and is 12 inches wide by 9.6 inches deep and can contain up to seven expansion slots. The Micro-ATX (mATX) standard specifies a 9.6-inch (244 x 244 mm) square board. mATX boards can have a maximum of 4 expansion slots. Small Form Factor (SFF) PCs are popular as home machines and for use as mini servers. SFF PCs often use Via's Mini-ITX (Information Technology Extended) form factor. Mini-ITX is a 6.7 inch (170 x 170 mm) square with one expansion slot. These are designed for small cases but do note that most mini-ITX boards can be mounted in ATX cases.

A hardware technician is ordering power supply units (PSUs) for the organization's desktop computers. What type of form factor is the technician looking for the PSUs to have from the list below? A. ATX B. SFF C. PCIe D. Mini-ITX

A. ATX Because The technician is looking for the PSUs that have the Advanced Technology Extended (ATX) specification as most PSUs designed for use with desktop PCs are based on the ATX form factor. Small form factor (SFF) personal computers are popular as home machines and for use as mini servers and often use Via's Mini-ITX form factor. The peripheral component interconnect express (PCIe) bus uses point-to-point serial communications and is the mainstream interface for modern adapter cards. The Mini-ITX (Information Technology Extended) form factor is appropriate for small form factor (SFF) personal computers which are popular as home machines and for use as mini servers.

An energy company is strengthening its defenses and wants to look for methods that successfully protect trade secrets by ensuring none of its company computing assets are hijacked by malware. To assist in safeguarding the sensitive information, what can the technician enable to ensure this will not happen? A. TPM B. HSM C. Encryption D. Secure boot

D. Secure boot because The technician can configure secure boot which is a unified extensible firmware interface (UEFI) feature designed to prevent malware from hijacking a computer. A trusted platform module (TPM) is a specification for hardware-based storage of digital certificates, cryptographic keys, and hashed passwords. A hardware security module (HSM) is a secure USB key or thumb drive used to store cryptographic material where a user must authenticate before they can access the keys stored on the module. Encryption products make data secure by scrambling it in such a way that only a user with the correct decryption key can subsequently read it.

A manager directs a support technician to plug a device into the communications (COM) port. What port is the manager referring to? A. IDE B. SCSI C. USB D. Serial

D. Serial Because In Windows, the serial port, or Recommended Standard #232 (RS-232) port, is also known as a communications (COM) port. The integrated drive electronics (IDE) interface was the principal mass storage interface for desktop PCs for many years and is also known as Parallel Advanced Technology Attachment (PATA). A small computer system interface (SCSI) is one example of a legacy parallel bus where one SCSI host bus adapter (HBA) can control multiple devices attached by internal ribbon cables or external SCSI cables. While modern interfaces like the universal serial bus (USB) are serial, an RS-232 interface, which is known as a COM port on Windows, uses much less sophisticated signaling methods.

A hardware technician is upgrading a device with multiple, identical central processing unit (CPU) packages. What class of computer is the technician most likely upgrading? A. Workstation B. Mobile C. Desktop D. Server

D. Server Because The technician is upgrading a server-class computer. Server motherboards are often multi-socket, meaning that the technician can install multiple, identical CPU packages. Regarding workstation-class PCs, most vendors use the term workstation to mean a high-performance PC, such as one used for software development or graphics/video editing. Many mobiles, such as smartphones, tablets, and laptops, use advanced RISC machine (ARM)-based CPUs and need to prioritize power and thermal efficiency plus weight over pure performance. The desktop segment covers a wide range of performance levels, from budget to gaming PC. These performance levels show up in the CPU manufacturer's ranges.

A security technician is installing a doorbell/video entry system for a customer so that the customer can see and communicate with people who come to their home when they aren't there. What kind of device is the doorbell/video entry system? A. Zigbee B. Hub and control system C. OT D. Smart device

D. Smart device Because The doorbell/video entry system is a smart device which is a device or appliance that users can configure and monitor over an IoT network. Zigbee is a wireless technology. While the control system is typically joined to the Wi-Fi network, smart devices may use other wireless technologies, such as Z-Wave or Zigbee, to exchange data via the hub. A hub and control system are each required by IoT devices. The hub facilitates wireless networking while the control system operates the device. An embedded system network is known as an operational technology (OT) network to distinguish it from an IT network.

A network technician is upgrading a legacy network for a small business and is replacing their legacy hub with a device that learns MAC addresses and uses them to forward frames to only the destination port, rather than sending them out to every port. What kind of device is the technician replacing the hub with? A. NIC B. Patch panel C. PoE D. Switch

D. Switch Because The technician replaces the hub with a switch that tracks MAC addresses for each of its ports and uses learned MAC addresses to forward frames to the destination port only. Each Ethernet network interface card (NIC) port has a unique hardware/physical address, called the "media access control" (MAC) address and Ethernet data identifies the source and destination MAC addresses in a header. In most types of office cabling, a technician connects a computer to a wall port and the cabling running through the walls connects to a patch panel. Power over Ethernet (PoE) is a means of supplying electrical power from a switch port over ordinary data cabling to a powered device (PD).

A network technician is purchasing a digital subscriber line (DSL) service for a business that transfers large amounts of data back and forth between branches. What is the best connection type for the business? A. ADSL B. ISP C. PSTN D. Symmetric DSL

D. Symmetric DSL Because Symmetric versions of DSL offer the same uplink and downlink speeds and are of more use to businesses and for branch office links, where more data passes upstream than with normal internet use. Asymmetrical DSL (ADSL) provides a fast downlink but a slow uplink, with the latest (ADSL2+) offering downlink rates up to about 24 Mbps and uplink rates of 1.25 Mbps or 2.5 Mbps. Internet service providers (ISPs) establish high-speed links between their networks, using transit and peering arrangements to carry traffic to and from parts of the internet they do not physically own. The public switched telephone network (PSTN) is the national and global telecommunications network that has fiber optic cabling at its core.

An organization located on a large piece of rural property needs to connect its office building on the north side of the property with its warehouse and shipping operation on the south side of the property. The organization decides to connect the locations using long-range fixed wireless. What frequency spectrum must the organization use to ensure that nobody else can use the same frequency band? A. Unlicensed B. Licensed C. 802.11ax D. DFS

B. Licensed Because A licensed frequency spectrum means that the organization purchases the exclusive right to use a frequency band within a given geographical area from the regulator. Unlicensed spectrum means the operator uses a public frequency band, such as 900 MHz, 2.4 GHz, and 5 GHz. Anyone can use these frequencies, meaning that interference is a risk. 802.11ax, or Wi-Fi 6, can support up to eight clients, giving it better performance in congested areas. Wi-Fi 6 also adds support for uplink MU-MIMO and OFDMA. Dynamic frequency selection (DFS) is a regulatory feature of wireless access points that prevents the use of certain 5 GHz channels when in the range of a facility that uses radar.

A technician is troubleshooting a computer that will not turn on. The technician has verified that the wall socket and devices leading to the computer are working correctly. What could remain as an issue? (Select all that apply). A. On-premises distribution circuit B. Motherboard C. Power supply unit D. Power grid

B. Motherboard C. Power supply unit Because Since the technician verified power was working in the wall socket and verified all other power components between the wall socket and the computer, the motherboard is most likely an issue. Since the technician verified power was working in the wall socket and verified all other power components between the wall socket and the computer, a faulty power supply unit is most likely an issue. An On-premises distribution circuit would stop power from reaching the wall socket. Since the technician verified power was working in the wall socket, this could not be the issue. The power grid would not be the issue as the technician verified that power was being delivered from the wall socket to the computer.

A software developer is creating an application that will run multiple parallel threads through the central processing unit (CPU) at the same time to reduce the amount of "idle time" the CPU spends waiting for new instructions to process. What type of process is the developer taking advantage of? A. Multi-socket B. Multithreading C. Multicore D. Processor extensions

B. Multithreading Because The developer is taking advantage of multithreading which is when software runs multiple parallel threads through the CPU at the same time to reduce "idle time." Server motherboards are often multi-socket which means they use two or more physical CPUs, referred to as symmetric multiprocessing (SMP), to deliver performance benefits. Multicore refers to a CPU design that puts two chips onto the same package. Most CPUs are multicore (more than two cores). Multicore and multithreading features are designated by nC/nT notation. Processor extensions support virtualization, also referred to as hardware-assisted virtualization, and make the VMs run much more quickly.

A network administrator configures an authentication, authorization, and accounting (AAA) server. Which component in the AAA server setup does not store authentication credentials, but acts as a transit to forward data between devices? A. Supplicant B. NAP C. RADIUS D. AAA

B. NAP Because The network access point (NAP) or network access server (NAS) are appliances, such as switches, access points, and VPN gateways. These do not store authentication credentials but simply act as a transit to forward this data between the AAA server and the supplicant. The supplicant is a component of the authentication, authorization, and accounting server and is the device requesting access, such as a user's PC or laptop. Remote Authentication Dial-in User Service (RADIUS) is a protocol that manages remote and wireless authentication infrastructures and implements AAA. In an authentication, authorization, and accounting (AAA) configuration, the AAA server is the authentication server positioned within the local network.

A technician is troubleshooting a projector that keeps randomly shutting down. What is the most likely cause? A. Burned-out bulb B. Overheating C. Loose cable between the monitor and display D. Incorrect data source

B. Overheating Because Overheating typically causes intermittent projector shutdown. Check that the projector's fan is working, that the vents are free from dust and obstructions, and that the ambient temperature is not too high. A completely failed bulb is known as a burned-out bulb. A technician might hear the bulb "pop" and observe scorch marks on the inside or a broken filament. If the display is on but there is no display, the technician should check the cable and connectors between the video card and monitor. If the projector is on but no image displays, the technician may need to adjust the image or select the appropriate data source or input channel.

Company employees access the same resources on the internet many times a day. As such, a network administrator configures a solution that forwards traffic to and from the internet and also caches content to improve performance and reduce bandwidth consumption. What solution is the administrator implementing? A.NAT B. Proxy server C. UTM D. Load balancer

B. Proxy server Because A proxy server takes a whole HTTP request from a client, checks it, then forwards it to and from the destination server on the internet. It also caches content to improve performance. In a port-based or overloaded network address translation (NAT), a NAT device translates between the private IP addresses used on the LAN and the public IP address on the router's WAN interface. A unified threat management (UTM) appliance enforces a variety of security policies and controls, combining the work of multiple security functions. A load balancer distributes client requests across server nodes in a farm or pool and can deploy in any situation where multiple servers are providing the same function.

A network technician needs to replace a broken Ethernet cable. What kind of connector will the technician use to terminate the new cable? A. F-type B. RJ-45 C. SC D. LC

B. RJ-45 Because Modular RJ-45 connectors terminate twisted pair cabling for Ethernet. RJ45 connectors are also known as "8P8C," standing for eight-position/eight-contact. Manufacturers typically terminate coax for CATV installations using a screw-down F-type connector. A subscriber connector (SC) terminates fiber optic cables and has a push/pull design that allows for simpler insertion and removal than a fiber channel (FC) connector. A lucent connector (LC) terminates fiber optic cables and is a small form factor connector with a tabbed push/pull design. LC is similar to SC, but the smaller size allows for higher port density.

An energy company is upgrading its systems across multiple sites. The company would like to control the systems with software that communicates with the current programmable logic controllers (PLCs) and new RTUs. What kind of system is the company upgrading to? A. OT B. SCADA C. Embedded system D. ICS

B. SCADA Because The company is upgrading to a supervisory control and data acquisition (SCADA) system which takes the place of a control server in large-scale, multiple-site ICSs. An embedded system network is known as an operational technology (OT) network to distinguish it from an IT network. An embedded system is an electronic device that performs a specific, dedicated function. Embedded systems might typically have operated within a closed network. An industrial control system (ICS) provides mechanisms for workflow and process automation. An ICS controls machinery used in critical infrastructures, such as power and water suppliers.

A hardware technician is purchasing mass storage devices and tells the salesperson that they must use flash memory technology. What type of devices will the salesperson show the technician? A. HDD B. SSD C. RAM D. CDs

B. SSD Because The salesperson will show the technician solid-state drives (SSDs) which use flash memory technology to implement persistent mass storage. Hard disk drives (HDDs) store data on metal or glass platters that have a magnetic coating on them. The drive accesses the top and bottom of each platter by its own read/write head. Random-access memory (RAM) storage technology is nonpersistent. Nonpersistent means that the RAM devices can only hold data when the PC is on. Compact Discs (CDs) are a mainstream storage format for music and video. All types of optical media use a laser to read the data encoded on the disc surface.

A web designer plans out a new website, including the uniform resource locators (URLs) for each page. What are parts of the URL that the web designer will need to consider? (Select all that apply.) A. File server B. FQDN C. Protocol D. File path

B. FQDN C. Protocol D. File path Because The designer will need to consider the fully qualified domain name (FQDN) which is not case sensitive. The host location can also be an IP address; an IPv6 address must be in square brackets. The designer will need to consider the protocol which describes the access method and will likely be HyperText Transfer Protocol (HTTP) or HyperText Transfer Protocol Secure (HTTPS). The designer will need to consider the file path which specifies the directory and file name location of the resource (if required). The file path may or may not be case sensitive. In file server-based networks, a central machine provides dedicated file and print services to workstations. Benefits of server-based networks include ease of administration through centralization.

An engineer is designing a new computer system and wants to provide active cooling to improve airflow and dissipate heat from around the components. What will the engineer use in the system? A. Heat sinks B. Fans C. Thermal paste D. Thermal pads

B. Fans The engineer will use fans, which actively improve airflow and help to dissipate heat. Engineers use fans on the power supply and chassis exhaust points. A heat sink is a block of copper or aluminum with fins. The fins expose a larger surface area to the air around the component to achieve a passive cooling effect by convection. Thermal paste "glues" a heat sink to the surface of a chip to ensure the best transfer of heat by eliminating small air gaps. A thermal pad performs a similar function to thermal paste. The pad is a compound that is solid at room temperature but softens when heated.

A network technician is purchasing cellular phones for people who are travelling to a rural area and wants to make sure they will work with the most networks, as the areas do not have the latest cellular technology. What type of phones will help the technician accomplish this? A. CDMA B. GSM C. Firewall D. Router

B. GSM Because Global System for Mobile Communication (GSM)-based phones allow subscribers to use a removable subscriber identity module (SIM) card to use an unlocked handset with their chosen network provider. Code division multiple access (CDMA) is a method of multiplexing a communications channel using a code to key the modulation of a particular signal. A network firewall is a software or hardware device that protects a network segment or individual host by filtering packets to an access control list. A router is an intermediate system working at the network layer capable of forwarding packets around logical networks of different layer 1 and layer 2 types.

A technician is able to use the standard adapter built into a computer's motherboard to connect to the company's network. What kind of network is the company most likely using? A. Fast Ethernet B. Gigabit Ethernet C. Fiber optic D. Wi-Fi

B. Gigabit Ethernet Because The company is using Gigabit Ethernet as many PC motherboards have a built-in 1000BASE-T Gigabit Ethernet compatible adapter. 100BASE-T refers to Fast Ethernet over copper twisted pair cabling. Fast Ethernet works at 100 Mbps. If the company was using a fiber-optic network, the technician would have to use a network interface card (NIC) adapter that supports fiber optic as this is not a standard type of adapter on motherboards. The Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of standards defines Wi-Fi which uses radios and antennas for data transmission and reception.

To mitigate the heat a high-end gaming system will generate, an engineer is using a liquid-based cooling system in the design. Which of the following components are NOT a part of an open-loop, liquid-based cooling system? A. Fans B. Heat sinks C. Water blocks D. Water loop

B. Heat sinks Because Heat sinks are not a part of a liquid-based cooling system. A heat sink is a block of copper or aluminum with fins which expose a larger surface area around the component to the air. Fans are a part of a liquid-based cooling system and engineers position them at air vents to dispel the excess heat. Water blocks and brackets attach to each device to remove heat by convection. These attach in a similar way to heat sink/fan assemblies and then connect to the water loop. A water loop is a part of a liquid-based cooling system and the water loop/tubing and pump push the coolant added via the reservoir around the system.

A technician is troubleshooting an issue with a computer. Although the computer is on the network, the server will not authenticate a user. What kind of problem does this indicate? A. Disk failure B. Inaccurate date/time C. Cabling issues D. Overheating

B. Inaccurate date/time Because If the computer does not correctly synchronize the date and time with other computers on the network, security systems such as authentication will not work. A hard disk drive (HDD) is most likely to fail due to mechanical problems either in the first few months of operation or after a few years. The technician not securely connecting the cables at both ends, the cable has become stretched or crimped, or an incorrect cable specification may all cause cabling issues. Unusual odors, such as a burning smell or smoke, will almost always indicate something (probably the power supply) is overheating.

A network technician sets up the wireless network in such a way that each client device connects to the network via an access point (AP). What type of configuration is this? A. Frequency bands B. Infrastructure mode C. DFS D. Channels

B. Infrastructure mode Because Infrastructure mode means that the technician configures each client device (station) to connect to the network via an access point (AP). A frequency band is a portion of the microwave radio-frequency spectrum in which wireless products operate, such as the 2.4 GHz band or 5 GHz band. Dynamic frequency selection (DFS) is a regulatory feature of wireless access points that prevents the use of certain 5 GHz channels when in range of a facility that uses radar. Wi-Fi products have frequency bands. Channels are smaller bands with those frequency bands that allow multiple networks to operate at the same location without interfering with one another.

A company uses a database that a developer wrote in-house. Since the database is not supported and the developer has left the organization, what is the database considered to be? A. BYOD B. Legacy system C. Embedded system D. UTM

B. Legacy system Because When a vendor no longer supports a system, it is a legacy system. This might be because the vendor has gone out of business or formally deprecated use of the product. Bring your own device (BYOD) is a provisioning model that allows employees to use personal mobile devices to access corporate systems and data. An embedded system is an electronic device that performs a specific, dedicated function. Embedded systems might typically have operated within a closed network. A unified threat management (UTM) appliance is one that enforces a variety of security policies and controls, combining the work of multiple security functions.

A technician loans a laptop to employees when they go on travel and each time an employee returns the laptop the technician reformats it and reloads the operating system and all the software. After several years of following this process, the laptop is sluggish and often freezes. What is most likely to cause this to happen? A. Motherboard B. SSD C. RAM D. CDs

B. SSD Because Solid-state drives (SSDs) use flash chips that are susceptible to a type of degradation over the course of many write operations which would cause the laptop to be sluggish and freeze. The motherboard houses sockets for the devices that implement the core system functions of a personal computer: compute, storage, and networking. Random-access memory (RAM) storage technology is nonpersistent. Nonpersistent means that the RAM devices can only hold data when the PC is on. Compact Discs (CDs) are a mainstream storage format for music and video. All types of optical media use a laser to read the data encoded on the disc surface.

An application developer wants to ensure packets arrive at the destination in the correct order and none are lost when an application communicates across the network. Which protocol will the application developer use? A. UDP B. TCP C. IP D. DNS

B. TCP Because The Transmission Control Protocol (TCP) can identify and recover from lost or out-of-order packets. Failing to receive a packet or processing it incorrectly can cause serious data errors. The User Datagram Protocol (UDP) is faster than TCP and comes with less of a transmission overhead because it does not need to send extra information to establish reliable connections. The Internet Protocol (IP) provides packet addressing and routing within a network of networks. For data to travel from one IP network to another, an intermediate system must forward it. The Domain Name System (DNS) is a service that maps fully qualified domain name labels to IP addresses on most TCP/IP networks, including the internet.

A technician is implementing a feature that will compare hashes of key system state data during the boot process to ensure that nobody has tampered with the system firmware, boot loader, and OS kernel. What feature is this? A. HSM B. TPM C. Encryption D. Boot password

B. TPM Because The technician is implementing the trusted platform module (TPM) which, during the boot process, compares hashes of key system state data to ensure they have not been tampered with. A hardware security module (HSM) is a secure USB key or thumb drive used to store cryptographic material where a user must authenticate before they can access the keys stored on the module. Encryption products make data secure by scrambling it in such a way that only a user with the correct decryption key can subsequently read it. A boot password requires the user to authenticate before the operating system is loaded. There are usually at least two passwords, though some systems may allow for more.

A hardware technician is following CompTIA's A+ troubleshooting model for diagnosing a monitor with a squiggly screen. The technician suspects the monitor screen is squiggly because it is located directly under a fluorescent light. What is the next step the technician should take? A. Identify the problem. B. Test the theory. C. Establish a plan of action. D. Verify full system functionality.

B. Test the theory. Because The technician has established a theory of probable cause so the next step in CompTIA's A+ troubleshooting methodology is to test the theory to determine the cause. The first step in CompTIA's A+ troubleshooting methodology is to identify the problem by gathering information from the user and inquiring about environmental or infrastructure changes. The second step of CompTIA's A+ troubleshooting methodology is to establish a theory of probable cause and, if necessary, conduct external or internal research based on symptoms. To verify full-system functionality and, if applicable, implement preventive measures is the fifth step of CompTIA's A+ troubleshooting methodology.

Which of the following statements regarding modern connectors and ports is untrue? A. They use edge contacts. B. They use internal connection points. C. They sometimes use keying. D. They can be reversible.

B. They use internal connection points. Because An input/output (I/O) port is the external connection point for a particular type of bus interface and the connector is the part of a peripheral cable that inserts into a port with the same shape. Most connectors and input/output ports now use edge contacts that connect the cable wires to the circuit boards. A lot of available connectors and ports have an asymmetric design called keying to prevent users from inserting them the wrong way around. A reversible connector is a connector that can be inserted into a socket in either orientation. The most typical variations of reversible connectors are Apple's Lighting connector and USB Type C.

A support technician needs to install an optical disk drive in a new tower. Which panel should be removed so that the technician can gain access to the optical drive and connect the cables? A. Through the top panel B. Through the side panel C. Through the rear panel D. Through the bottom of the rear panel

B. Through the side panel Because The technician will be able to hook up the optical media drive through the side panel. A tower case has a side cover that a technician can remove by sliding the panel from its housing. Although some tower computers have top panels, they are primarily used for various controls such as power. Top panels are not used for the installation of optical disks. The rear panel provides access to the power supply unit (PSU) sockets. The PSU has an integral fan exhaust. At the bottom of the rear panel there are cutout slots aligned with the position of adapter card slots to allow cables to connect to any input/output (I/O) ports on the cards.

An employee is leaving the company and must return any removable storage devices they may have. What devices will the employee most likely return? (Select all that apply.) A. Wireless card B. USB flash drive C. SD card D. RAM

B. USB flash drive C. SD card Because The employee will most likely return universal serial bus (USB) drives which are a type of flash drive and are simply a flash memory board with a USB connector and protective cover. The employee will most likely return secure digital (SD) cards. SD cards are a proprietary type of memory card that can have different sizes and performance ratings. Computers can have an installed wireless card that allows internet connectivity without the requirement for a hard connection. This is connected directly to the motherboard and is not a removable storage device. Random-access memory (RAM) is not removable storage. RAM is nonpersistent. Nonpersistent means that the RAM devices can only hold data when the PC is on.

A network technician is connecting a computer to the network using Ethernet. How is the physical connection to the cable made? A. Using the MAC address B. Using the RJ45 port C. Using a patch panel D. Using PoE

B. Using the RJ45 port Because In Ethernet communications, a RJ45 port in the computer's network interface card (NIC) establishes the physical connection to the cable. Each Ethernet network interface card (NIC) port has a unique hardware/physical address, called the "media access control" (MAC) address and Ethernet data identifies the source and destination MAC addresses in a header. In most types of office cabling, a technician connects a computer to a wall port and the cabling running through the walls connects to a patch panel. Power over Ethernet (PoE) is a means of supplying electrical power from a switch port over ordinary data cabling to a powered device (PD).

A company hired a network technician to manage the part of their network that is based on the 802.11 standard. What type of network will the technician be managing? A. LAN B. Wi-Fi C. MAN D. WAN

B. Wi-Fi Because The technician will be managing the Wi-Fi portion of the company's network. Most Wi-Fi networks are based on the IEEE 802.11 series of standards. Most cabled local area networks (LANs) are based on the 802.3 Ethernet standards maintained by the Institute of Electrical and Electronics Engineers (IEEE). A metropolitan area network (MAN) refers to a specific network type covering an area equivalent to a city or other municipality. A wide area network (WAN) spans multiple geographic locations. A company dedicated to facilitating access to the internet from local networks is an internet service provider (ISP).

An administrator needs to supply power to a handset through the switch; however, the switch does not support Power over Ethernet (PoE). How can the administrator solve this problem? A. A managed switch B. An unmanaged switch C. A power injector D. A hub

C. A power injector Because If a switch does not support PoE, the administrator can use a device called a "power injector." The administrator connects one port on the injector to the switch port and the other port to the device. Switches designed for larger LANs are managed switches. An administrator can connect to one of these switches over a management port and choose options for the switch's more advanced functionality. An unmanaged switch performs its function without requiring any sort of configuration. It establishes Ethernet connectivity between the network interfaces connected to it without any more intervention. A hub is a legacy network hardware device that implemented the 10BASE-T and 100BASE-T Ethernet cabling designs.

A hardware technician is tearing apart a non-functioning computer to salvage parts and pulls out a memory stick that synchronizes its speed to the motherboard system clock and has a peak transfer rate of 1600MBps. What type of memory has the technician removed? A. SDRAM B. Dynamic RAM C. DDR SDRAM D. ECC RAM

C. DDR SDRAM Because Modern system RAM is double data rate synchronous dynamic random access memory (DDR SDRAM) and makes two data transfers per clock cycle and has a peak transfer rate of at least 1600MBps. Synchronous DRAM (SDRAM) is so-called because its speed is synchronized to the motherboard system clock. Dynamic RAM stores each data bit as an electrical charge within a single bit cell. A bit cell consists of a capacitor to hold a charge and a transistor to read the contents of the capacitor. Error correcting code (ECC) RAM runs in workstations and servers that require a high level of reliability.

A network technician is configuring hosts to request IP configuration from a server. What protocol is the technician configuring? A. HTTPS B. SSH C. DHCP D. TFTP

C. DHCP Because The technician is configuring Dynamic Host Configuration Protocol (DHCP) which is a protocol used by clients to request IP configuration information from a server. HyperText Transfer Protocol Secure (HTTPS) is a protocol used to deliver web pages and other resources. It uses encryption to authenticate the server and protect the information. Secure shell (SSH) is a protocol that accesses the command-line interface of a computer from across the network and uses encryption to authenticate the server and user and protect the information. Network devices typically use Trivial File Transfer Protocol (TFTP) to obtain a configuration file. The application protocol uses its own acknowledgment messaging, so it does not require TCP.

A web designer is securely uploading files to a web server. What protocol is the designer using to do this? A. SMB B. NetBIOS C. FTPS D. FTP

C. FTPS Because The plain File Transfer Protocol (FTP) allows a client to upload files to a web server, but it is unencrypted and poses a high-security risk. FTP-Secure (FTPS) encrypts FTP sessions and is more prevalent than FTP now. Server Message Block (SMB) is the application protocol underpinning file and printer sharing on Windows networks. SMB usually runs directly over the TCP/445 port. Windows previously used Network Basic Input/Output System (NetBIOS) instead of TCP/IP. NetBIOS allowed computers to address one another by name and establish sessions for other protocols, such as SMB. File Transfer Protocol (FTP) allows a client to upload and download files from a network server. A common use of FTP is uploading files to websites.

A user started a brand-new Windows computer and received a "boot device not found" error. When the technician inspects it, what will they suspect the problem is? A. POST B. BSOD C. GPT D. Pinwheel

C. GPT because The technician will suspect the problem is with the GPT as this is a modern boot scheme where the boot information is not on a single sector but still identifies partitions and OS boot loaders. POST, a power-on self-test, is a diagnostic program implemented in the system firmware that checks the hardware to ensure the components required to boot are present and functioning correctly. This is a diagnostic method, not a potential cause for boot errors. A Windows system will display a blue screen of death (BSOD) to indicate that there is a system memory fault, a hardware device/driver fault, or corruption of operating system files. A macOS system that suffers catastrophic process failure shows a spinning pinwheel (of death), also called a spinning wait cursor.

A small company hired a network technician to upgrade its network. Surprisingly the company was still using a legacy hardware device that configures a network into a star topology. What device was this? A. Managed switch B. PoE-enabled switch C. Hub D. Patch panel

C. Hub Because The company was using a hub, which is a legacy network hardware device that configured networks in what is referred to as a "star topology" because each end system is cabled to a concentrator (the hub). Switches designed for larger LANs are managed switches. An administrator can connect to one of these switches over a management port and choose options for the switch's more advanced functionality. A PoE-enabled switch is referred to as endspan power sourcing equipment (PSE). When supported, this device determines the device's power consumption and sets the appropriate supply voltage level. This is not a legacy device. In most types of office cabling, a technician connects a computer to a wall port and the cabling running through the walls connects to a patch panel.

A support technician is connecting a current standard extended integrated drive electronics (IDE) cable to a PC's motherboard and knows that pin 1 on the cable must match up with pin 1 on the port. How can the tech know where pin 1 is on the cable? A. Pin 1 has a blue stripe. B. Pin 1 has a black stripe. C. Pin 1 has a red stripe. D. Pin 1 has a grey stripe.

C. Pin 1 has a red stripe. Because On the cable, pin 1 has a red stripe. Manufacturers also key the connectors to prevent technicians from inserting them the wrong way around. An EIDE cable typically has three color-coded connectors. The blue connector is for the motherboard port and pin 1 on the cable will have a red stripe. An EIDE cable typically has three color-coded connectors. The black, or end, connector attaches to device 0, and pin 1 on the cable will have a red stripe. An EIDE cable typically has three color-coded connectors. The grey, or middle, connector attaches to device 1, and pin 1 on the cable will have a red stripe.

A technician is troubleshooting a video display that is fuzzy. What has caused this? A. Insecure connector B. Burn-in C. Resolution mismatch D. Incorrect color display

C. Resolution mismatch Because If the output resolution does not match the display device's native resolution, the image will appear fuzzy. This typically happens if the video card's driver is faulty or incorrectly configured. If a technician does not securely insert the video cable and connectors at both ends, this could cause a flickering or flashing image. Burn-in is when the same static image displays on-screen for an extended period and the monitor's picture elements are damaged. This causes a ghost image to "burn" permanently onto the display. If a computer produces digital art, it is very important that the technician calibrate the display to scanning devices and print output to avoid an incorrect color display.

A company hired an administrator to manage their computers that host the employees' shared resources and applications. What kind of computers will the administrator manage? A. Client B. SAN C. Server D. Datacenter

C. Server Because The administrator will manage the company's server computers. A company dedicates a server computer to running network applications and hosting shared resources. A client computer allows end users to access the applications and resources to do work. Desktop administrators usually manage a company's client computers. A storage area network (SAN) provisions access to a configurable pool of storage devices that is isolated from the main network and that only application servers can use. A datacenter has dedicated networking, power, climate control, and physical access control features all designed to provide a highly available environment for running critical applications.

Which of the following central processing unit (CPU) architectures implements a system-on-chip (SoC) where all the controllers, including video, sound, networking, and storage, are part of the CPU? A. IA-32 B. x86 C. x64 D. ARM

D. ARM Because Advanced RISC Machine (ARM) designs implement an SoC which means that all the controllers, including video, sound, networking, and storage, are part of the CPU. The IA-32 (Intel Architecture) and x86-32 instruction sets define a CPU as IBM PC compatible. Intel and Advanced Micro Devices (AMD) design and manufacture IA-32. The x86-32 and IA-32 instruction sets define a CPU as IBM PC compatible. Intel and Advanced Micro Devices (AMD) design and manufacture IA-32. The x64 instruction set, developed initially by AMD as AMD64 or x86-64, extends the x86 instruction set for 64-bit operation.

A networking student is learning about IP addressing and discovers which of the following facts are NOT true regarding IPv6? A. Divided into two main parts. B. Will replace IPv4. C. Expressed in hexadecimal notation. D. Expressed in dotted decimal notation.

D. Expressed in dotted decimal notation. Because To make IPv4 addresses easier to use, they are in dotted decimal notation. IPv6 addresses are in hexadecimal notation. An IPv6 address divides into two main parts: the first 64 bits designate the network ID, while the second 64 bits designate a specific interface. The pool of available IPv4 public addresses is not very large, compared to the number of devices that need to connect to the internet, so IP version 6 (IPv6) will replace IPv4 completely. IPv6 addresses are in hexadecimal notation. To express a 128-bit IPv6 address in hex, the binary address divides into eight double-byte (16-bit) values delimited by colons.

A company hires a network technician who is reviewing the network setup documentation. The technician sees that the company has fiber optic cable running all the way up to the building. This represents what type of connection? A. FTTC B. VDSL C. ONT D. FTTP

D. FTTP Because A fiber to the premises (FTTP) internet connection means that the service provider's fiber optic cable runs all the way to the customer's building. A fiber to the curb (FTTC) solution retains some sort of copper wiring to the customer premises while extending the fiber link to a communications cabinet servicing multiple subscribers. The service providers with their roots in telephone networks use very high-speed DSL (VDSL) to support FTTC. VDSL achieves higher bit rates than other DSL types at the expense of range. An optical network terminal (ONT) is a device that converts between optical and electrical signaling deployed to facilitate full fiber internet connection types.

A network technician is configuring an email connection that will have a permanent connection to the mail server. What kind of email connection is the technician configuring? A. SMTP B. HTML C. POP3 D. IMAP

D. IMAP Because The Internet Message Access Protocol (IMAP) is a mail retrieval protocol that supports permanent connections to a server and connecting multiple clients to the same mailbox simultaneously. In Simple Mail Transfer Protocol (SMTP), the SMTP server of the sender discovers the IP address of the recipient SMTP server by using the domain name part of the recipient's email address. HyperText Markup Language (HTML) web pages are plain text files with coded tags describing how to format the document. The Post Office Protocol (POP) is an early example of a mailbox access protocol. POP is generally known as POP3 because the active version of the protocol is version 3.

A support technician plugged a monitor with a USB C cable connector into a USB C port on the computer, but the monitor would not function. Why would the monitor not work? A. It was not an HDMI cable. B. It was not a DisplayPort cable. C. It was not a Lightning cable. D. It was not a Thunderbolt cable.

D. It was not a Thunderbolt cable. Because USB-C may not work for display purposes without a Thunderbolt-capable cable. Thunderbolt uses the same connectors as a USB-C cable. The high-definition multimedia interface (HDMI) cable is the most widely used video interface, but it has a beveled connector to ensure correct orientation and will not fit in a USB C port. The DisplayPort cable supports similar features to HDMI, but the Video Electronics Standards Association (VESA) keyed these connectors against incorrect orientation, and they will not fit in a USB C port. The Lightning port and connector cable are proprietary to Apple and only Apple's iPhone and iPad mobile devices use it.

As traffic is overloading an organization's website, the network administrator sets up another web server. What will the administrator configure to distribute traffic between the two servers? A. NAT B. Proxy server C. UTM D. Load balancer

D. Load balancer Because A load balancer distributes client requests across server nodes in a farm or pool and can deploy in any situation where there are multiple servers providing the same function. In a port-based or overloaded network address translation (NAT), a NAT device translates between the private IP addresses used on the LAN and the public IP address on the router's WAN interface. A proxy server takes a whole HTTP request from a client, checks it, then forwards it to the destination server on the Internet, and reverses the process when the reply comes back. A unified threat management (UTM) appliance enforces a variety of security policies and controls, combining the work of multiple security functions.

A network technician is upgrading a grocery store's checkout lines with contactless payment devices. What type of wireless technology are the payment devices based on? A. 802.11a B. Bluetooth C. RFID D. NFC

D. NFC Because he payment devices are based on near-field communications (NFC), which can work as both tag and reader to exchange information with other NFC devices. The IEEE 802.11a is a wireless standard that uses the 5 GHz frequency band only. The data encoding method allows a maximum data rate of 54 Mbps. Bluetooth is a short-range, wireless radio-network transmission medium normally used to connect two personal devices, such as a mobile phone and a wireless headset. A radio-frequency ID (RFID) is a means of encoding information into passive tags, which can be energized and read by radio waves from a reader device.

A network technician wants all PCs on the network to go to a server to get their boot settings. What boot option in system settings will the technician configure on the PCs? A. Fixed disk B. Optical drive C. USB D. Network/PXE

D. Network/PXE Because The technician will configure the network/preboot execution environment (PXE) setting which uses the network adapter to obtain boot settings from a specially configured server. The fixed disk (HDD or SSD) setting will allow the technician to select the hard drive sequence if there are multiple fixed drives installed on the PC. If a technician is performing a repair install from optical media, they might need to make the optical drive (CD/DVD/Blu-ray) device the highest priority. The technician would use the universal serial bus (USB) setting for OS installs and repair utility boot disks that are too large to fit on optical media.

A network technician is installing a device with an inductor that will copy all the traffic coming through the cable to a monitor port. What type of device is the technician installing? A. SMF B. MMF C. Active TAP D. Passive TAP

D. Passive TAP Because The technician is installing a passive test access point (TAP) which is a box with ports for incoming and outgoing network cabling that physically copies the signal from the cabling to a monitor port. Single-mode fiber (SMF) has a small core (8-10 microns) and carries a long wavelength (1,310 or 1,550 nm) infrared signal, generated by a high-power, highly coherent laser diode. Multi-mode fiber (MMF) has a larger core (62.5 or 50 microns) and carries a shorter wavelength infrared light (850 nm or 1,300 nm). An active TAP is a powered device that performs signal regeneration, which may be necessary for some circumstances.

A system engineer is configuring fault tolerance with a configuration that uses a logical striped volume with two mirrored arrays. What redundant array of independent disks is the engineer using? A. RAID 0 B. RAID 1 C. RAID 5 D. RAID 10

D. RAID 10 Because The engineer is configuring RAID 10 which is a nested RAID configuration that combines a logical striped volume (RAID 0) configured with two mirrored arrays (RAID 1). RAID 0 requires at least two disks and provides no redundancy at all. If any physical disk in the array fails, the whole logical volume will fail. RAID 1 is a mirrored drive configuration using two disks. Each write operation duplicates on the second disk in the set, introducing a small performance overhead. RAID 5 uses striping (like RAID 0) but with distributed parity. Distributed parity means that error correction information spreads across all the disks in the array.

A network technician securely connects to a remote server on port 3389. What protocol does the technician use? A. LDAP B. SSH C. Telnet D. RDP

D. RDP Because Remote Desktop Protocol (RDP) is Microsoft's protocol for operating remote graphical user interface (GUI) connections to a Windows machine. RDP uses port TCP/3389. The Lightweight Directory Access Protocol (LDAP) is a TCP/IP protocol used to query and update an X.500 directory, and current directory products widely support it. Secure Shell (SSH) is the principal means of obtaining secure remote access to UNIX and Linux servers and most types of network appliances (switches, routers, and firewalls). Telnet is both a protocol and a terminal emulation software tool that transmits shell commands and output between a client and the remote host.

A network technician troubleshoots a computer on the wired network that is experiencing slow network speeds. Which of the following would NOT be a possible cause for the technician to troubleshoot? A. Improperly terminated patch cords B. Improper speed/duplex configuration C. Another radio source broadcasting at the same frequency D. External interference on the cable

C. Another radio source broadcasting at the same frequency Because Another radio source broadcasting at the same frequency would cause interference and result in slow speeds for wireless devices, but this would not be relevant to a wired network. Improperly terminated patch cords can cause slow network speeds on a wired network. The technician should substitute the patch cord with a known good cable or verify patch cords using a cable tester. An improper speed/duplex configuration on the switch interface and network interface card (NIC) can cause slow network speeds on a wired network. This should usually be set to auto-negotiate. External interference on the structured cabling can cause slow network speeds on a wired network. A cable tester called a "certifier" can report detailed information about cable interference.

A support technician opened the case to a PC and saw a square socket component. What component has the support tech located? A. RAM B. Adapter C. CPU D. Drive

C. CPU Because The support technician is removing the central processing unit (CPU). Unlike any other connectors, the CPU socket is square, and the heat sink and fan are on top of it. System RAM is normally dual inline memory modules (DIMMs) fitted to motherboard slots. DIMM slots have catches at either end and are located close to the CPU socket. Support technicians can insert adapter cards into slots on the motherboard to install or upgrade interfaces that the motherboard's chipset does not support. Drives fit into a drive bay in the chassis and then connect to a serial advanced technology attachment (SATA) port via a cable and to the power supply via a SATA power or Molex connector.

A network technician used a tool that energizes each wire in a cable. When the technician sent energy to some of the wires, the LED on the tool did not light up. What tool was the technician using? A. Toner probe B. Tone generator C. Cable tester D. Loopback plug

C. Cable tester Because The technician was using a cable tester, which is a pair of devices that attach to each end of a cable and energize each wire in the cable to test if the wire is conducting a signal. A toner probe identifies a cable from within a bundle. This may be necessary when cable technicians have not properly labeled the cables. A tone generator applies a continuous audio signal on a cable to detect the signal and follow the cable over ceilings and through ducts. A loopback plug tests a network interface card (NIC) or switch port. When a technician connects a loopback plug to a port, a solid link LED shows that the port can send and receive.

A desktop technician has responded to a user whose computer is running slow. The user claims they did not do anything that would cause the computer to run slow. What should the technician do to try to determine the probable cause of the problem? (Select all that apply.) A. Repair the problem. B. Document the findings. C. Conduct research. D. Question the obvious.

C. Conduct research. D. Question the obvious. Because The technician should conduct research to identify or clarify symptoms and possible causes. One of the most useful troubleshooting skills is being able to perform research to find information quickly. The technician should question the obvious as sometimes the simplest things cause seemingly intractable problems. Diagnosis requires both attention to detail and a willingness to be systematic. The technician would not be able to determine if repair is the best option for the issue until after they established a theory and tested it. The technician would document the findings after they corrected the issue. Documenting the findings would give the technician the opportunity to add a complete description of the problem and its solution.

A technician is troubleshooting a failed redundant array of independent disks (RAID) configuration and is unable to access the RAID configuration utility. What does this indicate? A. Disk failure B. Boot process failure C. Controller failure D. Multiple disk failure

C. Controller failure Because If the technician cannot access the RAID configuration utility, this indicates that the controller itself is likely to have failed. However, the data on the volume should be recoverable. Most desktop-level RAID solutions can tolerate the loss of only one disk, so the technician should replace it as soon as possible. If the RAID failure affects the boot process, the technician can use the RAID configuration utility to verify its status. If a volume is not available, either multiple disks (more than the tolerated number of disks) have failed, or the controller has failed.

A technician is installing new RAM in a company's workstations. The IT supervisor wants all computers to have ECC RAM to ensure high levels of reliability. Which features are not associated with ECC RAM? (Select all that apply) A. The motherboard and the CPU must support ECC operation for it to be enabled. B. Most motherboards support either UDIMMs or RDIMMs, but not both. C. If a motherboard supports UDIMM, you can use both types synchronously. D. Mixing non-ECC UDIMMs and ECC UDIMMs will work with each other.

C. If a motherboard supports UDIMM, you can use both types synchronously. D. Mixing non-ECC UDIMMs and ECC UDIMMs will work with each other. Because The motherboard and CPU must support ECC operation for ECC RAM to be utilized in a system. If the motherboard does not support it, the RAM will not work. Most ECC RAM are supplied as RDIMMs or registered DIMMs. A motherboard is typically configured to support RDIMM or unbuffered DIMM (UDIMM), but never both. If a motherboard is configured to support unbuffered DIMM, it must have UDIMM RAM installed. It will not be able to support RDIMM RAM. Similar to mixing RDIMM and UDIMM, computers are configured to use ECC or non-ECC UDIMM, but never both.

A college that has several campuses located in different parts of the city has hired a network technician. What type of network will the technician be working on? A. LAN B. Wi-Fi C. MAN D. WAN

C. MAN because The network technician will be working on a metropolitan area network (MAN), which can be a company with multiple connected networks within the same metropolitan area. A local area network (LAN) is a group of computers connected by cabling and one or more network switches that are all installed at a single geographical location. A wireless local area network (WLAN), also known as Wi-Fi, uses radios and antennas for data transmission and reception. Most WLANs are based on the IEEE 802.11 series of standards. A wide area network (WAN) spans multiple geographic locations. One example of a WAN is the internet, a global network of networks.

A technician started up a computer and the power-on self-test (POST) issued a short beep. What does this indicate? A. Motherboard problem B. Faulty speaker C. Normal POST D. POST error

C. Normal POST because When POST runs and issues one short beep, this indicates a normal POST, and the system is OK. However, manufacturers configure most modern PCs to boot silently. POST will indicate a motherboard problem with either no beep, repeating short beeps, or one long beep followed by a short beep. When there is a faulty speaker, the power-on self-test will indicate this with no beeps because the speaker is not working. If the power-on self-test runs but detects a problem, it generates two short beeps and shows an error message on the screen.

A technician retrieved a computer from storage, powered it on, and shortly began to notice a burning smell. What does this indicate? A. Disk failure B. Cabling issues C. Overheating D. Inaccurate date/time

C. Overheating Because Unusual odors, such as a burning smell or smoke, will almost always indicate something (probably the power supply) is overheating. A hard disk drive (HDD) is most likely to fail due to mechanical problems either in the first few months of operation or after a few years. The technician not securely connecting the cables at both ends, the cable has become stretched or crimped, or an incorrect cable specification may all cause cabling issues. If the network does not correctly synchronize the date and time, security systems will not work and utilities such as backup programs and schedulers will be unreliable.

A technician is wirelessly transferring pictures from their camera to their computer. What kind of network does the technician establish? A. Wi-Fi B. LAN C. PAN D. WLAN

C. PAN Because The technician has established a personal area network (PAN) which refers to using wireless connectivity to connect to devices at a range of a few meters. Wi-Fi is the brand name for the IEEE 802.11 standards that can be used to implement a wireless local area network (WLAN). A local area network (LAN) is a group of computers connected by cabling and one or more network switches that are all installed at a single geographical location. A wireless local area network (WLAN), also known as Wi-Fi, uses radios and antennas for data transmission and reception. Most WLANs are based on the IEEE 802.11 series of standards.

A network technician is trying to locate the Cat 6A cable in a closet full of unmarked boxes with different types of cabling in them. How will the technician be able to tell which cable is Cat 6A? (Select all that apply.) A. The words "twisted pair cable" is on the cable jacket. B. The TIA/EIA standard is on the cable jacket. C. The Cat specification is on the cable jacket. D. The cable type is on the cable jacket.

C. The Cat specification is on the cable jacket. D. The cable type is on the cable jacket. Because The technician can locate the cable by looking at the cable jacket since manufacturers print the Cat specification on the cable jacket. The technician will locate the cable by looking at the cable jacket because manufacturers print the cable type, such as UTP unshielded twisted pair (UTP) or foiled/unshielded twisted pair (F/UTP), on the cable jacket. The words "twisted pair cable" are not on the cable jacket of Ethernet cables, but the Cat specification and the cable type, such as unshielded twisted pair (UTP) or foiled/unshielded twisted pair (F/UTP), is on the cable jacket. The TIA/EIA-568-C Commercial Building Telecommunications Cabling Standards define the Cat specifications, but this is not on the cable jacket. TIA/EIA refers to the Telecommunications Industry Association/Electronic Industries Alliance.

A support technician needs to install a legacy peripheral component interconnect (PCI) sound card. Which of the following statements about PCI is NOT true? A. PCI Express supersedes PCI. B. PCI uses parallel communications. C. The PCI card can fit into the PCIe slot. D. PCI is software compatible with PCIe.

C. The PCI card can fit into the PCIe slot. Because PCIe (Peripheral Component Interconnect Express) motherboards can include PCI ports to support legacy adapter cards, but PCI cards cannot fit into PCIe slots. PCI Express supersedes Peripheral Component Interconnect (PCI), which is a legacy bus type, but computers can support more than one expansion bus. PCI uses parallel communications to increase bandwidth. Most types of PCI are 32-bit and work at 33.3 MHz, achieving a transfer rate of up to 133 MBps. PCI is software compatible with PCIe, meaning that PCIe motherboards can include PCI ports to support legacy adapter cards.

A network technician must allow employee computers to securely connect to the corporate network from alternate locations. What is the best method for the technician to use? A. DMARC B. DHCP scope C. VPN D. VLAN

C. VPN Because A virtual private network (VPN) enables hosts to connect to the LAN from locations other than the site by connecting to the local network via a secure remote access server. The Domain-Based Message Authentication, Reporting, and Conformance (DMARC) framework ensures that Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) are effective. A Dynamic Host Configuration Protocol (DHCP) scope is the range of addresses that a DHCP server can offer to client hosts in a particular subnet. A virtual LAN (VLAN) is a logical network segment comprising a broadcast domain established using a feature of managed switches to assign each port a VLAN ID.

A video production company uses removable media to transport multimedia files to partner and customer sites. Often, the media has to be prepared with only very short notice. In the past, the time taken to transfer files from the development workstations has resulted in delays and missed appointments. To mitigate this issue, the company has procured USB 3.2 Gen 2x2 storage devices and Windows PC workstation expansion cards. The devices and expansion cards support multiple USB hardware port types. Which of the following adapter cables will enable the devices to take full advantage of the highest transfer rate? A. Type A to Type A with USB 3 compatibility (denoted by a blue tab) B. Type B Micro to Type A with USB 3 compatibility (denoted by a blue tab) C. Lightning to Type A D. Type C to Type C

D. Type C to Type C Because Type A ports and connectors enhanced to support USB 3 are denoted by a blue tab, but this physical interface only supports speeds up to 10 Gbps (USB 3.2 Gen 2x1). Type B Micro USB 3 interfaces only support speeds up to 10 Gbps (USB 3.2 Gen 2x1). The Lightning connector and port is mostly used by Apple iPhone and iPad mobile devices. Though it is present on some storage devices, a Type A to Lightning adapter cable would not support the USB 3.2 Gen 2x2 20 Gbps transfer rate. Type C connectors and ports support data transfers at the USB 3.2 Gen 2x2 20 Gbps rate. The connector is also much smaller than Type A and is reversible. These improvements mean that other USB connector form factors are being phased out.

A hardware technician is purchasing more servers for an organization and needs to ensure the power supply units in the data center have the correct output to support them. What is a power supply unit's output capability measured as? A. Power B. Voltage C. Watts D. Wattage rating

D. Wattage rating The wattage rating is the measurement of the power supply unit's output capability. Servers have units rated over 300 W to meet the demands of multiple CPUs, additional memory modules, etc. Power is the rate at which things generate or use energy and scientists measure it in watts (W) and calculate it for electrical components as voltage multiplied by current (V*I). Voltage is the difference in potential between two points in an electric field and voltage multiplied by current (V*I) calculates power. Watts (W) are units of power, which is the rate at which things generate or use energy, and scientists calculate power for electrical components as voltage multiplied by current (V*I).

A wireless network technician is upgrading the access points in a conference center to provide better Wi-Fi connectivity during conferences. What standard will provide connectivity to the most clients? A. MU-MIMO B. Wi-Fi 5 C. OFDMA D. Wi-Fi 6

D. Wi-Fi 6 Because Wi-Fi 6 (802.11ax) can support up to eight clients, giving it better performance in congested areas. Wi-Fi 6 also adds support for uplink MU-MIMO and OFDMA. In Wi-Fi 5, downlink multiuser MIMO (DL MU-MIMO) allows an access point to use its multiple antennas to send data to up to four clients simultaneously. In practice, most Wi-Fi 5 (802.11ac) access points only support 4x4 streams. A single stream over an 80 MHz channel has a nominal rate of 433 Mbps. Wi-Fi 6 introduces orthogonal frequency division multiple access (OFDMA) which can work alongside MU-MIMO to improve client density.