Topic 6, Backbone Distribution Systems Flashcards
You have been asked to project manage a fiber cable backbone installation. In the course of the installation, you notice the fiber cable with a 25 mm (1 in) outside diameter is being installed into a small TR, and the cable is being installed into a tight corner. Based on your knowledge of minimum bend radius requirements for fiber cable, you must ensure that the
MINIMUM cable bend radius of _______________ is provided when the cable installation is completed.
A. 254 mm (10 in)
B. 305 mm (12 in)
C. 381 mm (15 in)
D. 457 mm (18 in)
E. 610 mm (24 in)
A. 254 mm (10 in)
Multimode optical fiber is generally used for campus or building applications due to the ability to use cost effective:
A. Connectors
B. Cable
C. Installation methods
D. Transceivers
E. Designs
D. Transceivers
When designing a backbone distribution system, you will need to include a telecommunications enclosure (TE). A TE can be defined as a:
A. Splice point for copper cabling only
B. Point where the backbone cabling interfaces to the horizontal cabling and may be utilized in place of a traditional Telecommunications Room (TR)
C. Location for housing building cross-connect cabling only
D. Location to house the splice transitioning from outdoor to indoor cabling only
E. Facility to store slack copper and fiber cables
B. Point where the backbone cabling interfaces to the horizontal cabling and may be utilized in place of a traditional Telecommunications Room (TR)
When designing a campus distribution system involving small buildings with only one horizontal cross-connect (HC) [Floor distributor (FD)] per building, you can eliminate the need for a(n):
A. Intermediate cross-connect (IC) Building distributor (BD)
B. Main cross-connect (MC) Campus distributor (CD)
C. Horizontal cross-connect (HC) Floor distributor (FD)
D. Entrance facility (EF)
E. Latching connector (LC)
A. Intermediate cross-connect (IC) Building distributor (BD)
One advantage of using preconnectorized jumpers and cables is:
A. They are less costly than field connectorized connectors
B. The cables are more rugged and can handle higher pull tensions
C. They come with factory certified quality of terminations
D. They require additional engineering time thereby providing a higher degree of reliability
E. The technician does not need to be concerned with the water blocking components of the cable
C. They come with factory certified quality of terminations
The maximum vertical rise is the distance over which the cable is vertically self-supporting.
This distance is a function of the weight of the cable and the:
A. Sheath fire rating
B. Number of strands of fiber in the cable
C. Type of hangers used in the riser
D. Type of fire stop used in the riser
E. Cable maximum tensile rating
E. Cable maximum tensile rating
You are given a choice of methods of routing backbone cabling vertically through a building. The one option that you do NOT want to use is:
A. Open shafts
B. Metallic raceways
C. Slots
D. Sleeves
E. Elevator shafts
E. Elevator shafts
When designing a fiber backbone using cable with an armored sheath, a major consideration that you must address is:
A. Type of metal used in the sheath
B. Strength of the armored sheath
C. Amount of aluminum contained in the armored sheath
D. Amount of steel in the sheath as rust is an issue
E. Bonding and grounding of the armored sheath
E. Bonding and grounding of the armored sheath
The RECOMMENDED balanced twisted-pair cable for building backbone cabling consists of ________ round solid copper conductors with a nominal characteristic of 100 ohm.
A. 20-24 AWG
B. 22-26 AWG
C. 23-24 AWG
D. 24-22 AWG
E. 26-20 AWG
D. 24-22 AWG
When designing a backbone distribution system, you are asked to include a combination of media types. Your choice of media types include:
A. Copper and fiber only
B. Fiber and wireless only
C. Fiber and coaxial cable only
D. Wireless and coaxial cable only
E. Any combination of copper, fiber, and wireless
E. Any combination of copper, fiber, and wireless
Rack mounted hardware is installed in two standard sized racks or cabinets. Those sizes are:
A. 482 mm (19 in) and 584 mm (23 in)
B. 482 mm (19 in) and 762 mm (30 in)
C. 610 mm (24 in) and 762 mm (30 in)
D. 762 mm (30 in) and 914 mm (36 in)
E. 482 mm (19 in) and 1020 mm (40 in)
A. 482 mm (19 in) and 584 mm (23 in)
A backbone star topology shall have no more than______ level(s) of cross-connections.
A. One
B. Two
C. Three
D. Four
E. Five
B. Two
Which of the following statements best describes what a backbone distribution system typically provides?
A. Cabling from the HC to the WA
B. Pathway from the HC to the WA
C. Conduit in a building riser
D. Building connections between floors in a multistory building
E. Copper cabling installed in a large building
D. Building connections between floors in a multistory building
One of the advantages of using optical fiber in the backbone installation is:
A. More cost effective
B. Immunity to EMI
C. Safer to install
D. Requires less skill to install
E. Has better manufacturer support
B. Immunity to EMI
A campus backbone design linking two buildings requires that you install a high-fiber-count cable very quickly, using the conduit system provided. Cost is not so much an issue as urgency is to meet a service demand. Your first choice of fiber cable installation is to use:
A. Multiple sheathed cables with field connectorization
B. Multiple sheathed cables using pigtail connectorization
C. Single high fiber count sheathed cable with field connectorization
D. Single sheathed high-fiber-count cable with pigtail connectorization
E. Single sheathed cable equipped with preconnectorized assemblies
E. Single sheathed cable equipped with preconnectorized assemblies
When reviewing a backbone distribution system within a building provided to you for standards compliance, you see that there are several cables with bridge taps built in.
Which one of the following options is correct?
A. Ensure all cables meet maximum lengths to ensure standards compliance
B. Ensure all cables exceed minimum cable lengths to avoid NEXT(near-end crosstalk)
C. Provide recommendations to remove all bridge taps
D. Provide recommendations to remove one bridge tap per cable
E. Do nothing as the design will pass all design parameters
C. Provide recommendations to remove all bridge taps
In reviewing your client’s network needs for today and 5 years into the future, you note their current specs call for a 1Gb/s network within a campus environment, with little or no possibility of any increased bandwidth demands until they move to their planned future site.
The building is not large, and the cable lengths will not exceed 550 m (1804 ft). Your recommendation for the fiber to be installed in the backbone is:
A. OM1 fiber
B. OM2 fiber
C. OM3 fiber
D. OM1, OM2, or OM3 will work
E. OS1 equipped with attenuators
B. OM2 fiber
You have been asked to design a backbone cable connecting two large campus buildings.
Your pathways will include using conduits, maintenance holes, and one section of 100 m
(328 ft) of direct buried optical fiber cable. Your choice of fiber optic cable type recommendation is a:
A. Distribution cable
B. Loose tube cable
C. Loose tube cable containing a water blocking compound
D. Distribution cable with an armored coating
E. Distribution cable with a water blocking compound
C. Loose tube cable containing a water blocking compound
In the customer’s environment, an ITS designer should avoid the need for optical fiber field splicing by:
A. Installing oversized inner duct
B. Using oversized cable trays
C. Using pre-connectorized cables
D. Installing a continuous length of cable
E. Using multiple pull boxes
D. Installing a continuous length of cable
Optical fiber all-dielectric cables have an additional advantage over ones containing a steel strength member. That advantage is:
A. More resistant to rodent damage
B. More difficult to damage
C. More resistant to lightning and electrical conduction
D. Cables are made of a tougher outer PVC jacket
C. More resistant to lightning and electrical conduction
An installation crew is pulling an optical fiber cable into a riser. The cable has an outside diameter of 25 mm (1 in). As the cable is being pulled off the reel and through a pulley into the riser, you must verify that the minimum bend radius for the cable being pulled is observed. The pulley must be sized at a MINIMUM of:
A. 254 mm (10 in)
B. 381 mm (15 in)
C. 508 mm (20 in)
D. 635 mm (25 in)
E. 762 mm (30 in)
B. 381 mm (15 in)
When installing a heavy backbone cabling vertically, recommended methods of securing the cable include all of the following EXCEPT:
A. Tie wraps
B. Brackets
C. Steel or plastic straps
D. Collar or mesh basket grips
E. Steel cable ties
A. Tie wraps
You are reviewing a building backbone design with a vertically aligned telecommunications room (TR). In the spec you note in a footnote with details that the slots at one end of the telecommunications room (TR) must be flush with the floor and the sleeves provide at the end of the telecommunications room (TR) must also be flush. In your meeting with the electrical engineering firm that has provided the spec, you make the comment that according to best practices, the MINIMUM that slots and sleeves must extend above the finished floor are:
A. 25 mm (1 in) for slots and 51 mm (2 in)
B. 25 mm (1 in) for slots and 25 mm (1 in)
C. 51 mm (2 in) for slots and 25 mm (1 in)
D. 51 mm (2 in) for slots and 51 mm (2 in)
E. 64 mm (2 1/2 in) for slots and 64 mm (2 1/2 in)
B. 25 mm (1 in) for slots and 25 mm (1 in)
The decision regarding the number of optical fibers to install (fiber strand count) in a backbone depends largely on all of the following EXCEPT:
A. Level of multiplexing
B. Intended end-user applications
C. Physical topology of the cabling system
D. Distance between telecommunications room (TR)
E. Cabling system configuration
D. Distance between telecommunications room (TR)
