* Chapter 4 - Backbone Distribution Systems

Question 1

What is a backbone distribution system?

Answer 1

The part of a premises distribution system that provides connection between telecom spaces (ie MDF IDF DMarc). Typically connects between floors in multistory buildings, multi-buildning environments (Campus Backbone)

Question 2

Three types of Topologies

Answer 2

Star

Ring

Tree

Question 3

Star topology

Answer 3

Each building is connected to one main building

Question 4

OM1 Distance

Answer 4

2000m (6500’)

Question 5

OM2 Distance

Answer 5

550m (1800’)

Question 6

OM3 Distance

Answer 6

300m (1800’) 10Gb/s … 100m (328’) 100Gb/s

Question 7

OM4 Distance

Answer 7

550m (1804’) 10Gb/s … 150m (492’) 100 Gb/s

Question 8

OS1 Distance

Answer 8

10,000m (32,808’) 100 Gb/s

Question 9

OS2 Distance

Answer 9

10,000 (32,808’) 100Gb/s

Question 10

Types of steel conduit used for pathways

Answer 10

RMC - Rigid Metal Conduit
IMC - Intermediate Metal Conduit
EMT - Electrical Metallic Tubing

Question 11

RMC - Rigid Metal Conduit

Answer 11

Threaded metal raceway. This is the heaviest and thickest of the steel conduits. When galvanized, it typically has a coating of zinc on both sides. Galvanized makes it noncombustible and can be used indoors, outdoors, underground, concealed or exposed.

Question 12

IMC - Intermediate Metal Conduit

Answer 12

Threaded similar to RMC though IMC is about one third the weight and is thinner.

Question 13

EMT - Electrical Metallic Tubing

Answer 13

Also known as thin-wall. Unthreaded conduit. This is the lightest weight steel conduit and easiest to alter in the field (bends). Not recommended for use in underground or exterior applications because of its poor resistance to corrosion.

Question 14

PON

Answer 14

Passive Optical Network. Typically a point to multi point fiber to the premises network architecture in which unpowered optical splitters are used to enable a single fiber to serve multiple premises.

Other names for this are.. fiber to the edge, fiber to the home, fiber to the building, fiber to the curb

Question 15

Sleeve used for backbone distribution should be located a minimum of ____ from adjacent sleeves.

Answer 15

1”

Question 16

Ideally, the Main Crossconnect (MC) (Campus Distributer (CD)) would be co-located in the:

Answer 16

(ER) Equipment Room

Question 17

In a backbone distribution system, connections between any two floor distributors shall not pass through more than ___ cross-connection(s).

Answer 17

Three

Question 18

A backbone distribution shall not have more than ___ levels of cross connections.

Answer 18

2

Question 19

What color identifies the first level of interbuilding backbone?

Answer 19

Brown
This is the backbone going from the main cross connect of one building to the the horizontal cross connect of another building

Question 20

What color identifies the first level intrabuilding backbone? (intrabuilding refers to within the same building)

Answer 20

White
First level intrabuilding backbone refers to backbone going from Main cross connect to Intermediate Cross Connect or Horizontal Cross Connect.

Question 21

What color identifies the second level intrabuilding backbone?

Answer 21

Gray
Second level intrabuilding backbone refers to backbone going from Intermediate Crossconnect to Horizontal Cross connect

Question 22

In Ethernet over digital subscriber line (EoDSL) networks, 2Mb/s service (2PASS-TL) can be provided to subscribers over a maximum span of ____ using balanced twisted pair cable.

Answer 22

8858ft

Question 23

Sleeves used for backbone distribution should be constructed to extend a minimum of __ and a maximum of ___ above the floor level.

Answer 23

Minimum of 1in
Max of 3in

Question 24

A minimum of ___ sleeves are required for floor to floor backbone distribution with an addition one sleeve per ____.

Answer 24

4 sleeves
additional sleeve per 40,000 sq ft

Question 25

A typical floor slot for backbone distribution should have a minimum depth of ___ and a minimum length of ____.

Answer 25

Minimum depth of 6in
Minimum length of 10in

Question 26

A typical floor slot for backbone distribution should have a maximum depth of ___ .

Answer 26

24in

Question 27

Slots used for backbone distribution should be sized at ___ per 40,000 sq ft and increased by ___ per additional 40,000sq ft of usable space.

Answer 27

60 in sq per 40,000 sq ft
increased by 12 in sq per additional 40,000 sq ft

Question 28

The maximum balanced twisted-pair backbone length for voice systems should not exceed:

Answer 28

2625ft

Also, total length between network equipment connections should not be greater than 328ft.

Question 29

What are the advantages of using a star topology for the campus backbone cabling?

Answer 29

• Provides centralized facilities administration
• Allows testing and reconfiguration of the systems topology and applications from the MC (CD)
• Allows easy maintenance and security against unauthorized access
• Provides increased flexibility
• Allows the easy addition of future campus backbones