Objective 2.1

What type of cable transmits lights from end to end?

Fiber-optic Remember that fiber-optic cable transmits a digital signal using light impulses. Light is carried on either a glass or a plastic core.

How many hosts on a half-duplex segment can talk at one time?

One In half-duplex communication, a device can either send communication or receive communication, but it cannot do both at the same time.

How many wire pairs are used with 100BaseTX full duplex?

Two Full-duplex Ethernet uses two pairs of wires at the same time.

Which of the following Ethernet unshielded twisted-pair cabling types is/are commonly used?

-1000BaseTX -10BaseT -100BaseTX UTP is commonly used in twisted-pair Ethernet like 10BaseT, 100BaseTX, 1000BaseTX, and so on.

You are designing a network for Perfect Wear Inc. You need to make a choice between 100BASE-FX and 100BASE-TX. What are the two prime differences between 100BASE-FX and 100BASE-TX?

-100BASE-FX is fiber-based, whereas 100BASE-TX is copper-based. -The maximum segment length of 100BASE-FX is longer than that of 100BASE-TX. 100BASE-FX is a fiber-based media, whereas 100BASE-TX is copper-based. This enables 100BASE-FX to have longer segment lengths. 100BASE-FX is an IEEE baseband specification for Ethernet. This is also known as FDDI. It supports the maximum speed of 100Mbps and the maximum cable length of 412 meters in half duplex and 2,000 meters in full duplex connections. 100BASE-FX uses fiber-optic cables. 100BASE-TX is an IEEE baseband specification (IEEE 802.3u) for Ethernet. This is commonly known as Fast Ethernet. It supports the maximum speed of 100Mbps and the maximum cable length of 100 meters. 10BASE-TX uses Category 5 UTP or STP cables. It uses an RJ-45 connector.

Which of the following statements are true about a CAT5 cable?

-Capable of transferring data at 100Mbps -Has three twists per inch of each twisted pair -Uses a 24-gauge copper wire Cat 5 cable is a twisted pair high signal integrity cable type. Most cables of this type are unshielded, but some are shielded, used for high signal integrity. These cables can transfer data at speeds of 100 Megabits per second. So, these cables typically have three twists per inch of each twisted pair of 24 gauge copper wires within it. The twisting of the cable can reduce electrical interference and crosstalk. These cables are used in structured cabling for computer networks, such as Fast Ethernet.

A company has decided to change the old Cat 3 UTP cables with Cat 6 UTP cables throughout the offices. For this, spools of cable have been purchased and the network technician has been asked to properly terminate the cables to every end devices. Which of the following tools should the network technician use to accomplish the task?

-Crimper -RJ-45 connector Wire crimpers are the most common tools found in a network administrator's tool kit. A wire crimper looks like a pair of pliers. It is used to connect different types of connectors to the cable. To attach the connector, the cable and connector are inserted into the crimper and its handles are pressed. This connects the connector to the cable. Since the cable used is Cat 6 UTP, an RJ-45 connector is the most common connector that can be used. A type 45 registered jack (RJ-45) is an eight-pin connector found in most Ethernet networks.

Why would a network administrator use plenum-rated cable during an installation?

-It reduces toxic gas released during a fire. -It has high combustion temperature. Plenum-rated means that the cable's coating doesn't begin burning until a much higher temperature is reached, doesn't release as many toxic fumes as PVC when it does burn, and is rated for use in air plenums that carry breathable air, usually as non-enclosed fresh-air return pathways that share space with cabling.

In which of the following coaxial cables is implementation of Ethernet not applicable?

-RG-59 -RG-6 (table)

Which of the following connectors will be used to connect a serial port and an Ethernet port on a switch?

-RJ-45 -DB-9 A type 45 registered jack (RJ-45) is an eight-pin connector found in most Ethernet networks. The unshielded twisted-pair (UTP) and shielded twisted-pair (STP) connections use RJ-45 connectors in computer networks. A DB-9 connector is used on serial cables. Serial cables use the RS-232 protocol which defines the functions of the 9 pins in a DB-9 connector. It is an older connector used for low-speed asynchronous serial communications, such as a PC to a serial printer, a PC to a console port of a router or switch, or a PC to an external modem.

Which of the following types of connectors are used for unshielded twisted-pair connections?

-RJ-45 -RJ-11 RJ-45 and RJ-11 connectors are used for unshielded twisted-pair connections. The RJ-45 connector is similar to an RJ-11 telephone connector, but is larger in size, because it has eight conductors; an RJ-11 connector only has four conductors (two pairs). An RJ-11 connector is the same connector that is used on a telephone wire, while an RJ-45 connector is used for copper wire Ethernet connections.

Which of the following connectors are used with fiber-optic cables?

-SC -ST -MT-RJ The following connectors are used with fiber-optic cables: SC connector: A subscriber connector (SC) is a fiber-optic connector used with multimode fiber. It is a square shaped connector used for terminating fiber optic cables. SC connectors have a push-pull latching mechanism to provide quick insertion and removal while also ensuring a positive connection. ST connector: A straight tip (ST) connector is a fiber-optic connector used with multimode fiber. An ST connector has a 2.5mm shaft and bayonet locking ring, and allows quick connect and disconnect of 125 micron multi-mode fiber. MT-RJ connector: The MT-RJ connector is the most recent type of small form factor fiber optic connector. The MT-RJ fiber connector is less than half the size of the SC duplex connector and transceiver, so it doubles the port density of fiber-optic LAN equipment. The connector is a 2-fiber connector and takes up no more room than an RJ-45 jack.

Which of the following are fiber-optic connectors?

-ST -SC -LC There are many different types of fiber-optic connectors. SC, ST, LC, and MT-RJ are some of the more typical connectors in use today.

A technician is setting up a direct connection between two older PCs so they can communicate but not be on the corporate network. The technician does not have access to a spare switch but does have spare Cat 6 cables, RJ-45 plugs, and a crimping tool. The technician cuts off one end of the cable. Which of the following represents the correct pin mapping that the technician should do to make a crossover cable before crimping the new plug?

1 > 3, 2 > 6, 3 > 1, and 6 > two A crossover cable is used to connect a computer to another computer, a hub to a switch, a hub to another hub, a switch to another switch, and a router to another router. The Crossover cable has eight wires inside the cable shield and two RJ-45 connectors at each end. In the crossover cable, two sets of wires are crossed over. The correct pin mapping of an Ethernet crossover cable is 1 > 3, 2 > 6, 3 > 1, and 6 > 2.

What is the maximum transmission distance of 1000BaseT?

100 meters (328 feet) 100BaseT and 1000BaseT both have a maximum transmission distance of 100 meters, or 328 feet.

What is the distance limitation of a Category 5 horizontal cross-connect cable?

100 meters (328 feet) A Category 5 or a Category 6 cable, has a maximum distance of 100 meters, or 328 feet.

Which of the following can run full duplex and achieve 200 Mbps with Cat 5e cable?

100BaseTX 100BaseTX uses CAT 5e and can run 200 Mbps when using full duplex.

Which of the following IEEE 802.3 standards support up to 30 workstations on a single segment?

10Base2 10Base2 (thinnet) supports up to 30 workstations on a single segment. It uses 10Mbps of baseband technology, coax up to 185 meters in length, and a physical and logical bus with Attachment Unit Interface (AUI) connectors.

Which of the following Ethernet standards is an implementation of 10 Gigabit Ethernet that uses long-wavelength lasers at 1310 nm over single-mode fiber?

10GBaseLR 10GBaseLR is an implementation of 10 Gigabit Ethernet that uses long-wavelength lasers at 1310 nm over single-mode fiber. It also has a maximum transmission distance between 2 meters and 10 km, or 6 miles, depending on the size and quality of the fiber.

On which of the following would a technician use a punch-down tool?

110 block A punch-down tool is used to punch down an RJ-45 cable to an insulation displacement connector, typically a 110 block.

What is the maximum transmission distance of 10GBaseSR?

300 meters A 10GBaseSR cable can have a maximum transmission distance of 300 meters.

What is the maximum transmission distance of 10GBaseLR?

6 miles A 10GBaseLR implementation can go a distance of up to 6 miles.

Which of the following specifications of IEEE (Institute of Electrical and Electronic Engineers) defines the standard for fiber-optic cables?

802.8 The IEEE formed a project, called Project 802 to help define certain LAN standards. Project 802 defines aspect of the network relating to physical cabling and data transmission, corresponding to the physical and data link layers of the OSI (Open System Interconnect) model. The 802 specifications contain twelve different categories. In these specifications, 802.8 is used to define standards for fiber-optic cables. Institute of Electrical and Electronics Engineers (IEEE) is an organization of engineers and electronics professionals who develop standards for hardware and software.

What does the Base mean in 100BaseTX?

Baseband 100 means 100 Mbps. The Base means baseband, which refers to baseband technology—a signaling method for communication on the network.

Why is fiber-optic cable immune to electromagnetic interference (EMI) and radio frequency interference (RFI)?

Because it transmits digital signals using light impulses Fiber-optic cable transmits digital signals using light impulses rather than electricity; therefore, it is immune to EMI and RFI.

Jennifer, a network administrator, is troubleshooting an expansion card in a computer that allows the computer to receive faxes over a VoIP line. The line connected to the expansion card is most likely which of the following cable types?

CAT6 A VoIP line uses the CAT6 cable which provides performance of up to 250 MHz and can be used up to a maximum length of 100 meters (55 meters for 10GBASE-T networks). CAT6 is backward compatible with the CAT3, CAT5, and CAT5e cable standards, and as with CAT5 and CAT5e cabling, CAT6 cables consist of four unshielded twisted pairs (UTP) of copper wire terminated by RJ-45 connectors. The CAT6 standard includes stringent specifications for crosstalk and system noise.

You need to connect two devices on a network and they need to send voice traffic. Which of the following cables will you use?

Cat 5 To connect two devices for voice on a vertical connect, the minimum cable you can use is Category 5.

In which of the following categories is UTP cable not rated?

Category 9 Unshielded twisted-pair has standards from Category 2 through 8 for use on Ethernet networks. There is no Category 9 defined.

A company's management has given a list of requirements to the network technician for a LAN connection using CAT6 cabling in an older building. The technician has to keep the environmental factors in mind during network installation. Which of the following should the network technician consider when deciding whether or not to use plenum-rated cables?

Ceiling airflow condition Whenever a cable is used in an enclosed environment, security becomes an important factor. As enclosed spaces are often humid and vulnerable to temperature extremes, it becomes important to plan properly for such conditions. In case of fires, normal cable produces toxic gas. Plenum is the space between ceilings which is used to circulate air through the building space. This space is also used for wiring and cabling. This is a place where fires can easily start. Therefore, network cables should be plenum rated otherwise when cables burn, their insulation gives off a poisonous smoke that gets circulated around the building. Plenum-rated cables come in fire-retardant plastic jacket that eliminates the risk of toxic smoke being circulated around the building.

Which cable type contains a center conductor made of copper that's surrounded by a plastic jacket with a braided shield over it?

Coaxial The coaxial cable contains a center conductor made of copper that's surrounded by a plastic jacket with a braided shield over it. It includes one physical channel that carries the signal surrounded (after a layer of insulation) by another concentric physical channel, both running along the same axis.

Which of the following types of media converter should be used for connecting a newly installed multimode connection to an existing CAT5e infrastructure?

Fiber to Ethernet Single-mode and multimode are cable types used in optical fiber cabling and Cat5e is an Ethernet cable. Therefore, a fiber to Ethernet media converter should be used that accepts a fiber connector and an Ethernet connector and converts the signal between them.

You work as a Network Administrator for Net World International. The Sales office and head office of the company are located in different buildings. You want to connect the Sales office network to the Head office network. The company's management is concerned about the electromagnetic interference (EMI) in the surrounding locality. Which of the following cables will you use?

Fiber-optic A fiber-optic cable is used for high-speed, high-capacity data transmission. It uses optical fibers to carry digital data signals in the form of modulated pulses of light. The prime features of a fiber-optic cable are described below: Supports greater signal bandwidth transmission Immune to electromagnetic interference (EMI) Transmits undistorted signals over great distances Electromagnetic interference (EMI) is the disruption in the effective functioning of an electronic device. It occurs when the device is within an electromagnetic field of another electronic device. Although it does not create very strong voltage sags or surges, it can distort data transmission to some extent.

On which type of cable does EMI have the least effect?

Fiber-optic Fiber-optic cable transmits only light (not electricity like UTP), so EMI has zero effect on it.

Jennifer, a network administrator, has been asked to install a network cable that offers the greatest level of resistance to electromagnetic interference (EMI). Which of the following network cables will she select?

Fiber-optic Jennifer should select the fiber-optic cable because it transmits digital signals using light impulses rather than electricity. It is immune to EMI and RFI.

What type of cable should be used if you need to make a cable run longer than 100 meters?

Fiber-optic Standards limit UTP to a mere 100 meters. Different fiber-optic types have different maximum lengths, but fiber-optic is the only cable type that can extend well beyond 100 meters.

How many wires are used in a 100BaseTX UTP transmission?

Four 100BaseTX utilizes only pins 1, 2, 3, and 6.

Which of the following devices does not support full-duplex communication?

Hub Full-duplex communication cannot be used with a hub because a hub is a half-duplex single communication device. A host, switch, and router have the ability to process traffic (frames), whereas a hub is a multiport repeater.

What is the main difference between a single-mode fiber (SMF) and a multimode fiber (MMF)?

Number of light rays The difference between single-mode fibers and multimode fibers is in the number of light rays (and thus the number of signals) they can carry. Generally, both have glass as the transmission medium. Multimode fiber is used for shorter-distance applications while single-mode fiber is used for longer distances.

How many wire pairs are used with half duplex?

One With half duplex, only one wire pair is used at a time, when a digital signal is either being transmitted or received.

How is a T1 crossover cable wired?

Pins 1, 2, 4, and 5 are connected to 4, 5, 1, and 2. A T1 cable uses pairs 1 and 2, so connecting two T1 CSU/DSU devices back-to-back requires a crossover cable that swaps these pairs. Specifically, pins 1, 2, 4, and 5 are connected to 4, 5, 1, and 2, respectively.

Ann, a network technician is replacing the existing cables in her company's remote location. She has to re-install a new cabling solution that will have 10 Gbps speed and can also be run between the structural and drop-down ceilings providing safety in case of fires. Which of the following will best meet this requirement?

Plenum, Cat 6a Cat 6a plenum rated cables will best meet the requirement of having 10 Gbps speed and providing safety in case of fires and accidents. Cat 6a cables support twice as many frequencies as Cat 6 and can be used for 10GBASE-T networks, which can transmit data at a rate of 10 billion bits per second (10 Gbps). Also, whenever a cable is used in an enclosed environment, like between the structural and drop-down ceilings, security becomes an important factor. As enclosed spaces are often humid and vulnerable to temperature extremes, it becomes important to plan properly for such conditions. In case of fire, normal cable produces toxic gas. Therefore, plenum-rated cables are used for such spaces.

You are a network administrator and currently planning for LAN cabling for a new area of your office building. The cable will run between the structural and drop-down ceilings. Which of the following cables will be best suited in this environment?

Plenum-rated Whenever a cable is used in an enclosed environment, security becomes an important factor. As enclosed spaces are often humid and vulnerable to temperature extremes, it becomes important to plan properly for such conditions. In case of fire, normal cable produces toxic gas. You must plan to use plenum-rated cable for such spaces. Plenum-rated cables are cables that meet applicable fire protection and environmental requirements. These cables are made to be used in enclosed (plenum) environment and are subjected to temperature and humidity extremes. Plenum-run cables are made of materials that are resistant to open flame and are non-toxic at high temperature. These cables produce less toxic gas during fire. Often these cables are covered with Teflon and are more expensive than ordinary cables. Both twisted pair and coaxial cables are available as plenum-rated versions. Plenum is used to indicate the enclosed spaces in buildings used for heating, ventilating, and air-conditioning airflow. It can be created by a false ceiling, a false floor, metal duct work, or other construction method. As plenums often connect rooms in a building, they provide convenient paths through which to run wiring.

Which of the following is among the benefits of a switch?

Provides extra bandwidth By allowing full-duplex operation on each port, a switch provides extra bandwidth to each port.

On which of the following types of cabling is an F-connector used?

RG-6 An F-connector is a coaxial RF connector commonly used for terrestrial television, cable television and universally for satellite television and cable modems, usually with an RG-6 cable. The RG-6 cable has a characteristic impedance of 75 Ohms.

Smith, a network administrator, wants to run a cable for a new PC and the requirement is the CAT6 cable. Which of the following connectors will he use when terminating the cable?

RJ-45 Smith will use the RJ-45 connector when terminating the CAT6 cable, which is a type of twisted pair cable. The RJ-45 connector is an eight-pin connector used in networking. All four pairs of wires in the twisted pair cable use this connector.

What type of connector does UTP cable typically use?

RJ-45 UTP usually connects with RJ-45. A crimper is used to attach an RJ connector to a cable.

Which of the following provides protection against network eavesdropping and signal interference and works at the physical layer?

Shielded twisted pair (STP) An STP cable provides protection against network eavesdropping and signal interference and works at the physical layer. It consists of one or more pairs of twisted wires that are insulated with a metal foil to minimize electromagnetic interference. The metal shield is connected to the ground to prevent external signals from getting into and internal signals from getting out of the cable. Shielding is a way of preventing electronic emissions that are generated from a computer or network. These emissions can be used by unauthorized users to gather confidential information. Shielding minimizes the chances of eavesdropping within a network.

Which of the following provides the longest cable run distance?

Single-mode fiber Single-mode fiber allows for the maximum cable run distances.

You need to crimp on a connector using an RJ-45 connector. Which pin-out configuration would you use to connect a host into a switch?

Straight-through You would use a straight-through cable to connect a host to a switch, and the typical pin-out is called T568A.

What is the effective total throughput increase with a full-duplex connection?

Twice as much In full-duplex communication, both devices can send and receive communication at the same time. This means that the effective throughput is doubled and communication is much more efficient.

You need to make a T568B cable for a Fast Ethernet link. How many pairs will you use?

Two Fast Ethernet is 100BaseTX and this type of cable uses two pairs of wires.

How many devices can be connected to a full-duplex segment?

Two Full-duplex communication requires a point-to-point configuration and uses two pairs of wires through which both devices can send and receive communication at the same time. This means that with full-duplex data transfer, you not only get faster data-transfer speeds, but you also get collision prevention too.

What is the maximum cable length supported by 10GBaseER Ethernet standard over a single mode fiber optic cable?

Up to 40 km 10GBaseER is an implementation of 10 Gigabit Ethernet running over single-mode fiber that uses extra-long-wavelength lasers at 1550 nm. It has the longest transmission distances possible of all the 10 Gigabit technologies: anywhere from 2 meters up to 40 km, again depending on the size and quality of the fiber used.

If you are using a cable medium called 10Base2, what does this mean?

You are using the old thinnet coax for your LAN medium 10Base2 was one of the very first Ethernet network physical mediums and is a thinnet coax.

A crossover cable is used to connect all of the following except _______________.

host to switch All devices that are pinned the same for transmit and receive require a crossover cable to communicate directly.