Infrastructure (1) Flashcards
Which of the following best describes the function of the network medium?
The network medium provides the physical connection between networked computers.
The network medium provides the protocol used to transmit data between end systems.
The network medium passes data between two routers.
The network medium provides the physical connection between networked computers.
The network medium provides the physical connection between networked computers. This connection can be made through a copper-based, fiber-optic, or wireless medium. The network medium is not a protocol, and it does pass data; it only carries signals. The network medium does not process electrical or light pulses and convert them to data; it carries only the signals generated by transceivers
Which of the following signal types is carried by copper cable?
Fiber optic
Infrared
Electrical
Electrical
Copper cables use electrical signals to transmit data. Fiber optic is a cable type, not a signal type. Microwave signals can’t be transmitted over copper cable. Infrared signals are used only for wireless networks
Identify the organizations that developed the general cable type standards for voice and data communications that are currently in use, and identify the document name.
EIA/ANSI/TWA, document 802.2
TDA/EIA/TIA, document 802.11
ANSI/TIA/EIA, document T568b
ANSI/TIA/EIA, document T568b
The three organizations that collectively developed the T568b document, which defines the standard for a structured cabling system for voice and data communications, are the American National Standards Institute (ANSI), the Telecommunications Industry Association (TIA), and the Electronic Industries Alliance (EIA). All of the other options are not standards organizations or cabling standards
Which of the following cable types and connectors are used to attach a television set to a cable television (CATV) network?
A fiber-optic cable and a straight tip (ST) connector
A twisted pair cable and an RJ-45 connector
A coaxial cable and an F-type connector
A coaxial cable and an F-type connector
The cable type and connector used to attach a television set to a CATV network is a coaxial cable with a screw-on F-type connector. Although CATV networks typically use fiber-optic cables and ST connectors for outdoor connections, they do not use fiber for internal connections to television sets. Coaxial cables with BNC connectors are most commonly used for Thin Ethernet LANs, not CATV network connections. Twisted pair cables and RJ45 connectors are used for Ethernet LANs and telephone networks, but not CATV networks. AUI cables and vampire tap connectors are used for Thick Ethernet networks
Which of the following cable types is used for Thick Ethernet network segments?
RG-8
RG-58
RJ-45
RG-8
The cable type used for Thick Ethernet segments is a coaxial cable called RG-8. RG-58 is used exclusively on Thin Ethernet segments. RJ45 is a connector type used in twisted pair cabling for data networks. RJ11 is a connector type used in twisted pair cabling for telecommunications networks
Which of the following cable types is used for Thin Ethernet network segments?
RG-8
RG-58
RJ-45
RG-58
RG-58 coaxial cable is used exclusively for Thin Ethernet segments. RG-8 cable is used for Thick Ethernet segments. RJ45 is a connector type used in twisted pair cabling for data networks. RJ11 is a connector type used in twisted pair cabling for telecommunications networks
Which of the following telecommunications components is all but obsolete and is found only in old, analog telephone installations?
66 block
110 block
Patch panel
66 block
A 66 block is a type of punchdown block for telephone systems that was first introduced in 1962. By the year 2000, nearly all commercial telephone installations had begun using 110 blocks instead; 110 blocks are still in use, as are patch panels and fiber distribution panels, both of which are termination points for network cable runs
Which of the following coaxial cable types are still in general use? (Choose all correct answers.)
RG-6
RG-8
RG-58
RG-59
RG-6
RG-59
RG-6 and RG-59 are 75 ohm cables that are still used for cable television and similar connections. RG-8 and RG-58 are 50 ohm cables that were formerly used for Thick Ethernet and Thin Ethernet, respectively, but are no longer in general use
Under which of the following conditions might the local building code require that a data network use plenum cable?
When multiple cables run through the same conduit
When cables run near to devices that generate electromagnetic interference (EMI)
When cables must run through heating ducts
When cables must run through heating ducts
A plenum space is an area of a building that provides air circulation as part of its heating or cooling system, such as a heating or air conditioning duct. Plenum cables have a sheath made of a fire retardant material that does not outgas toxic fumes should it be exposed to fire. When network cables are installed in plenum spaces, many local building codes require that installers use plenum-rated cables conforming to specific standards. Plenum cables provide no benefit when installed near other cables, or EMI sources, or when they exceed specified lengths
Which of the following statements about the differences between fiber-optic angle-polished connectors (APCs) and ultra-polished connectors (UPCs) are true? (Choose all correct answers.)
APCs should only be joined to other APCs.
APCs generate more insertion loss that UPCs.
UPCs generate more return loss than APCs.
UPCs use a green connector boot or body.
APCs should only be joined to other APCs.
APCs generate more insertion loss that UPCs.
UPCs generate more return loss than APCs.
Joining an APC to a UPC creates a mismatched connection that generates an extremely high rate of insertion loss (attenuation). APCs do generate more insertion loss than UPCs and less return loss (reflection). It is APCs, not UPCs, that use green boots or bodies on the connectors
Which of the following is not a type of fiber-optic connector?
MTRJ
ST
BNC
BNC
Bayonet-Neill-Concelman (BNC) is a type of connector used with coaxial cable. Subscriber connector (SC), mechanical transfer registered jack (MTRJ), and straight tip (ST) are all types of fiber-optic connectors
Which of the following physical layer transceiver module standards is the oldest and therefore the most obsolete?
BiDi
QSFP
GBIC
GBIC
The Gigabit Interface Converter (GBIC) transceiver standard was first published in 1995 and defines a maximum data transfer rate of 1.25 Gbps. It was rendered all but obsolete by the Small Form-factor Pluggable (SFP) standard, introduced in 2001, which ran at the same maximum speed but was smaller in size. Subsequent variations on the standard, such as Quad Small Form-Factor Pluggable (QSFP), defined devices with faster transfer rates. Bidirectional (BiDi) transceivers were developed to eliminate the need for separate transmit and receive fibers by using multiplexing
Which of the following cable types is typically configured in a star topology, uses eight copper conductors arranged in four pairs, and uses RJ-45 connectors?
RG-8
Twisted pair
RG-58
Twisted pair
There are two main types of twisted pair wiring used for data communications: unshielded twisted pair (UTP) and shielded twisted pair (STP). Both types can be used in a star topology. UTP and STP cables contain eight copper conductors twisted in four pairs. UTP and STP cables use RJ45 connectors to connect end systems to switches, patch panels, and wall plates. RG-8 and RG-58 coaxial cable can only be used in a bus topology. Fiber-optic cable can be used in a star topology, but it uses either glass or plastic conductors and doesn’t use RJ45 connectors
Which of the following statements explains the purpose of the twists in twisted pair cabling?
The twists prevent collisions.
The twists completely eliminate crosstalk and electromagnetic interference (EMI) in adjacent wire pairs.
The twists prevent crosstalk in adjacent wire pairs and limit the effects of EMI on the signals carried over the cable.
The twists prevent crosstalk in adjacent wire pairs and limit the effects of EMI on the signals carried over the cable.
The twists in a twisted pair cable prevent the signals on the different wires from interfering with each other (which is called crosstalk) and also provide resistance to outside electromagnetic interference. The twists have no effect on collisions. The twists can’t completely eliminate the effects of EMI. Twists have nothing to do with the bend radius allowance for the cable
Which of the following tools do cable installers use to add connectors such as RJ-45 and RJ-11 to twisted pair cabling?
A crimper
A splicer
A pigtail
A crimper
A crimper or crimping tool is a jawed device that has a set of dies in it. Installers use a crimper to squeeze the two halves of an RJ45 or RJ11 connector together, with the wires inside securing the connector to the cable. Installers use a splicing tool to splice two cable segments together. There is no tool called a pigtail or a patch