€h 06 - Backbone Distribution Systems

Question 1

6-4 Backbone Cross-connects

a backbone star topology =

Answer 1

no more than two levels of cross-connects

Question 2

6-4 Backbone Cross-connects

connections between any two HCs =

Answer 2

not pass through (3) cross-connections

Question 3

6-7 Additional backbone connections between TR’s

Bus or Ring Topology =

Answer 3

direct connection between TR’s

Question 4

6-8 Figure 6.6

Answer 4

Hierarchical star campus backbone

Question 5

6-9 one-level hierarchical star campus backbone design

MC =

(2)

Answer 5

* close to (if not located in ) the main ER

* center of the building ~ 10th flr of 20th flr bldg

Question 6

6-10 Figure 6.6

Answer 6

multiple heirarchical

Question 7

6-11 connecting outlying bldg’s in a physical ring

physical ring =

(2)

Answer 7

* seldom recommended, used for disaster recovery

* redundant cable path

Question 8

6-11 Figure 6.8

Answer 8

physical ring

Question 9

6-12 connecting outlying bldg’s in a physical ring

physical ring conduit system =

Answer 9

dedicate some for fiber ring and some to fiber star

Question 10

6-13 TR’s & ER’s

TR =

TE =

ER =

Answer 10

* architectural space

* a case

* environmentally controlled

Question 11

6-19 combined optical fiber & balanced twisted pair backbone

data systems =

voice systems =

Answer 11

* optical fiber

* twisted pair

Question 12

6-22 choosing optical fiber type

OM2 fiber =

Answer 12

1804ft 1Gb/s

Question 13

6-22 choosing optical fiber type

OM3 fiber =

Answer 13

984ft 10Gb/s

Question 14

6-22 choosing optical fiber type

Question/Answer

10G @ 286m =

Answer 14

OM3

Question 15

6-22 choosing media

transmission media =

(3)

Answer 15

* flexibility of medium

* required backbone

* site size and user population

Question 16

6-23 multimode optical fiber

multimode =

Answer 16

62.5/125 or 50/125

Question 17

6-23 singlemode optical fiber

singlemode =

Answer 17

1310/1550

Question 18

6-23 100ohm balanced twisted pair copper

building backbone =

campus backbone =

Answer 18

* 24 to 22 AWG

* 19 & 26 AWG

Question 19

6-23 performance categories of multipair backbone balanced twisted pair

2625ft backbone length =

Answer 19

voice systems

Question 20

6-25 TR’s

TR location & advantages =

(3)

Answer 20

*vertically aligned

*backbone is accessible

*circuits cab be distributed

Question 21

6-25 vertically aligned TR’s

sleeves or slots =

Answer 21

should not be directly above or below

Question 22

6-25 sleeves or slots

slots =

sleeves =

Answer 22

* 1 in. high curb

* 1 in. above the floor level

Question 23

6-26 sleeve quantity & configuration

inside (4) 4” =

Answer 23

add (1) spare 4” per 40,000 sqft

Question 24

6-26 sleeve quantity & configuration

40,000 sqt =

50,000 sqt =

Answer 24

* (5) 4” backbone conduits

* (5) 4” backbone conduits

Question 25

6-27 slot quantity & config

slots =

(2)

Answer 25

* flush against the wall within space

* 6 - 24 in

Question 26

6-27 slot quantity & config

slot sized =

Answer 26

(5 sqft) up to 40,000 sqft

Question 27

6-28 open shafts

open shafts =

Answer 27

large quantities distant from the main ER

Question 28

6-28 avoid

do not locate backbone =

Answer 28

elevator shafts

Question 29

6-29 supporting strand

support strand suspended =

Answer 29

highest floor of the building and basement

Question 30

6-29 supporting strand

steel strands =

Answer 30

0.25 in

Question 31

6-29 supporting strand

insert cable ties =

Answer 31

before overall strand tensioning

Question 32

6-29 supporting strand

place the ties approx =

Answer 32

min. of three ties per floor

Question 33

6-32 Optical fiber strand count

ITS designer must address =

Answer 33

* present and future telecom requirements

* optical fiber redundancy

* system administration

* maintenance

Question 34

6-33 sizing optical fiber backbone

most common application for optical fiber backbone cabling =

Answer 34

multiplexed transmission

Question 35

6-33 sizing optical fiber backbones

multiplexed transmission =

Answer 35

combines signals from many end points over 2 strands

Question 36

6-33 sizing optical fiber backbones

fiber backbone considerations =

Answer 36

* mulitplexers - strands to support current equipment

* spare - maintenance, redundancy, segregated and furture applications

Question 37

6-34 indoor hardware

indoor hardware =

Answer 37

varied, mounting, and design

Question 38

6-39 optical fiber cable benefits

multimode =

Answer 38

cost effective tranceivers

Question 39

6-39 optical fiber composition

fiberglass rods or aramid yarn =

Answer 39

all-dielectric cables

Question 40

6-39 optical fiber composition

tight buffered fiber =

loose tube fiber =

Answer 40

* 900um used indoor

* 250um used outdoor

Question 41

6-42 min bend radius

non-conductive backbone =

(2)

Answer 41

* bend radius of 10 times under no load

* bend radius of 15 times being pulled

Question 42

6-42 min bend radius

conductive backbone =

(2)

Answer 42

* bend radius of 10 times under no load

* bend radius of 20 times being pulled

Question 43

6-42 max vertical rise

no load =

Answer 43

sitting on spool and final install

Question 44

6-45 multiple sheaths and splice points

additional sheaths =

Answer 44

not splicing

Question 45

6-46 methods to terminate cable

methods to terminate cable =

Answer 45

* pigtail

* field connectorizing

* installation of preconnectorized assemblies

Question 46

6-46 methods to terminate cable

Q: If you need to install high fiber count and cost is nothe issue, what connector would you choose?

Answer 46

preconnectorized assemplies

Question 47

6-47 methods to terminate

pigtail splicing =

(2)

Answer 47

* factory connectorized on one end

* unterminated at the other end

Question 48

6-48 pigtail splicing

pigtail splicing advantages =

Answer 48

factory-certified connector termination

Question 49

6-49 preconnectorized assemblies

preconnectorized assemblies disadvantages =

Answer 49

may be higher in price