€h 06 - Backbone Distribution Systems Flashcards
6-4 Backbone Cross-connects
a backbone star topology =
no more than two levels of cross-connects
6-4 Backbone Cross-connects
connections between any two HCs =
not pass through (3) cross-connections
6-7 Additional backbone connections between TR’s
Bus or Ring Topology =
direct connection between TR’s
6-8 Figure 6.6
Hierarchical star campus backbone
6-9 one-level hierarchical star campus backbone design
MC =
(2)
* close to (if not located in ) the main ER
* center of the building ~ 10th flr of 20th flr bldg
6-10 Figure 6.6
multiple heirarchical
6-11 connecting outlying bldg’s in a physical ring
physical ring =
(2)
* seldom recommended, used for disaster recovery
* redundant cable path
6-11 Figure 6.8
physical ring
6-12 connecting outlying bldg’s in a physical ring
physical ring conduit system =
dedicate some for fiber ring and some to fiber star
6-13 TR’s & ER’s
TR =
TE =
ER =
* architectural space
* a case
* environmentally controlled
6-19 combined optical fiber & balanced twisted pair backbone
data systems =
voice systems =
* optical fiber
* twisted pair
6-22 choosing optical fiber type
OM2 fiber =
1804ft 1Gb/s
6-22 choosing optical fiber type
OM3 fiber =
984ft 10Gb/s
6-22 choosing optical fiber type
Question/Answer
10G @ 286m =
OM3
6-22 choosing media
transmission media =
(3)
* flexibility of medium
* required backbone
* site size and user population
6-23 multimode optical fiber
multimode =
62.5/125 or 50/125
6-23 singlemode optical fiber
singlemode =
1310/1550
6-23 100ohm balanced twisted pair copper
building backbone =
campus backbone =
* 24 to 22 AWG
* 19 & 26 AWG
6-23 performance categories of multipair backbone balanced twisted pair
2625ft backbone length =
voice systems
6-25 TR’s
TR location & advantages =
(3)
*vertically aligned
*backbone is accessible
*circuits cab be distributed
6-25 vertically aligned TR’s
sleeves or slots =
should not be directly above or below
6-25 sleeves or slots
slots =
sleeves =
* 1 in. high curb
* 1 in. above the floor level
6-26 sleeve quantity & configuration
inside (4) 4” =
add (1) spare 4” per 40,000 sqft
6-26 sleeve quantity & configuration
40,000 sqt =
50,000 sqt =
* (5) 4” backbone conduits
* (5) 4” backbone conduits
6-27 slot quantity & config
slots =
(2)
* flush against the wall within space
* 6 - 24 in
6-27 slot quantity & config
slot sized =
(5 sqft) up to 40,000 sqft
6-28 open shafts
open shafts =
large quantities distant from the main ER
6-28 avoid
do not locate backbone =
elevator shafts
6-29 supporting strand
support strand suspended =
highest floor of the building and basement
6-29 supporting strand
steel strands =
0.25 in
6-29 supporting strand
insert cable ties =
before overall strand tensioning
6-29 supporting strand
place the ties approx =
min. of three ties per floor
6-32 Optical fiber strand count
ITS designer must address =
* present and future telecom requirements
* optical fiber redundancy
* system administration
* maintenance
6-33 sizing optical fiber backbone
most common application for optical fiber backbone cabling =
multiplexed transmission
6-33 sizing optical fiber backbones
multiplexed transmission =
combines signals from many end points over 2 strands
6-33 sizing optical fiber backbones
fiber backbone considerations =
* mulitplexers - strands to support current equipment
* spare - maintenance, redundancy, segregated and furture applications
6-34 indoor hardware
indoor hardware =
varied, mounting, and design
6-39 optical fiber cable benefits
multimode =
cost effective tranceivers
6-39 optical fiber composition
fiberglass rods or aramid yarn =
all-dielectric cables
6-39 optical fiber composition
tight buffered fiber =
loose tube fiber =
* 900um used indoor
* 250um used outdoor
6-42 min bend radius
non-conductive backbone =
(2)
* bend radius of 10 times under no load
* bend radius of 15 times being pulled
6-42 min bend radius
conductive backbone =
(2)
* bend radius of 10 times under no load
* bend radius of 20 times being pulled
6-42 max vertical rise
no load =
sitting on spool and final install
6-45 multiple sheaths and splice points
additional sheaths =
not splicing
6-46 methods to terminate cable
methods to terminate cable =
* pigtail
* field connectorizing
* installation of preconnectorized assemblies
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?
preconnectorized assemplies
6-47 methods to terminate
pigtail splicing =
(2)
* factory connectorized on one end
* unterminated at the other end
6-48 pigtail splicing
pigtail splicing advantages =
factory-certified connector termination
6-49 preconnectorized assemblies
preconnectorized assemblies disadvantages =
may be higher in price
