Chapter 4 - Structured Cabling and Networking Elements

How far away from fluorescent lights or other sources of EMI should cable be installed?​

At least 3 feet

​One watt is equal to how many volt-amps?

1.4

​What is the maximum allowable distance for horizontal wiring?

100 m

Equipment racks most commonly come in what two widths?​

19 and 23 inch frame

Select the maximum allowable distances for horizontal wiring for a span that connects a data jack on a wall to a data closet, and for a span that connects a workstation to the data jack, respectively:

90 m and 10 m

Describe the differences between a brownout and a blackout.​

A blackout is a complete interruption of power in a given service area. Rolling blackouts are controlled and usually pre-planned interruptions of service. Blackouts come without warning, last for indeterminate periods, and are typically caused by catastrophic equipment failure or severe weather A brownout is a partial, temporary reduction in system voltage or total system capacity.

True or False? A power fluctuation that results in a temporary dimming of lights is known as a blackout.​

False

True or False? Cable that is coated with flame-resistant polyvinyl chloride (PVC) is acceptable for use in plenum areas.

False

Select the two Transport Layer protocols that are used by SANs:​

Fibre Channel and iSCSI

Explain how equipment should be configured in a rack to best optimize airflow and temperature.​

Hardware should be installed as close to the front of the rack as possible to allow for proper airflow in the back. Minimizing cable clutter can also help prevent airflow blockages

​In a chassis, the path along which air from a cool air source is conducted, past equipment to cool it, and then out of the rack. Typically, air moves from front to back.

airflow

Electrical power flow on a circuit that continually switches direction.

alternating current (AC)

A volt-ampere (VA) is the product of the voltage and the ________________ of the electricity on a line.​

current

​What cable type comes in two different modes, single mode and multimode?

​Fiber optic

​Which method of transmission allows signals to travel in both directions over a medium but in only one direction at a time?

​half duplex

​What component of the backbone runs between a building's floors and can be used to connect an MDF and IDF or multiple IDFs?

vertical cross connect

​A device that maintains a constant voltage level for either AC or DC electrical energy.

voltage regulator

Explain the difference between an inverter and a rectifier.

The difference between an inverter and a rectifier is that both perform opposite functions in electronic circuits. The Inverter converts Direct Current to Alternating Current. The rectifier does the opposite by converting Alternating Current to Direct Current.

True or False? A NIC card cannot determine whether the frames it transmits and receives are using IP packets or a different layer 3 protocol, because the NIC does not operate higher than Layer 2 of the OSI model.​

True

True or False? Each type of cable has a prescribed bend radius , which is the radius of the maximum arc into which you can loop a cable without impairing data transmission.

True

Select the component of enterprise level structured cabling that serves as the location where an incoming network interface enters a building and connects with the building's backbone cabling:

Entrance faculty

The field in a frame responsible for ensuring that data carried by the frame arrives intact. It uses an algorithm, such as CRC, to accomplish this verification.​

FCS (frame check sequence)

A _____________ allows for an MTU as high as 9198 bytes.​

Jumbo frame

In order to simplify console access to computers in a rack, what device is typically used to provide a central portal for all devices on the rack?​

KVM switch

Ethernet exists at what layer of the OSI model?​

Layer 2

A specialized storage device or group of storage devices that provides centralized fault-tolerant data storage for a network.​

NAS (network attached storage)

​During termination of twisted pair cabling, what should be done to ensure minimal cross talk is introduced?

No more than 1 inch of the cable should be exposed.

Describe the three different types of cabling recognized by TIA/EIA as acceptable for horizontal wiring.​

The three different types of cabling recognized by TIA/ELA are: UTP - A copper Cable that has 2 - 1800 unshielded twists pairs surrounded by an outer jacket. STP - cable that has a metal shield that can protects wires from electromagnetic or radio interference Fiber Optic - cable that contains strands of glass fibers inside the insulated casing. Design for high-performance and long distance data networking.

The portion of an Ethernet network in which collisions could occur if two nodes transmit data at the same time.​

collision domain

The flow of electrical power at a steady rate in only one direction.​

direct current (DC)

​If the use of a pre-existing Ethernet infrastructure is desired for a SAN, what Transport Layer protocol should be utilized?

iSCSI

A device that converts DC electrical energy to AC electrical energy. Better inverters will also condition thepower, which helps protect sensitive electronic equipment from power fluctuations.

inverter

A device that changes the form of electrical energy in some way. Four common types are inverter, rectifier, transformer, and voltage regulator.

power converter

​The industry-standard unit for measuring rack height. Standard racks are 42U tall — about 6 feet.

rack unit (RU or U)