TDMM Chapter 4 Flashcards by Daniel Barley

Backbone Distribution System

The part of the premesis distribution system that provides connection between telecom spaces

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Central Office
A common carrier switching exchange office

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Entrance Facility

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EFM

Ethernet in the First Mile
Term used to describe the access network from the access point to the subscribers premises

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Equipment Room

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HC (FD)

Horizontal Cross-Connect (Floor Distributor)
A group of connectors that allow equipment and backbone cabling to be cross-connected to horizontal cabling

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IC (BD)

Intermediate Cross-Connect (Bldg Distributor)
The connection point between backbone cable that extends from the MC (CD) first level backbone to the HC (FD) second level backbone

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MC (CD)

Main Cross-Connect (Campus Distributor)
The cross-connect normally located in the main equipment room for cross connection of entrance , backbone and equipment cables

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RMC

Rigid Metallic Conduit
A threaded metal raceway of circular cross section with coupling (no threaded)

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Telecommunications Enclosure
A case or housing that may contain telecommunications equipment, cable terminations or horizontal cross connect cabling

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Telecommunications Room

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Name the twp typical functions a backbone system provides in a campus

Building connections between floors in multi story buildings
Campus connections in multi building environments

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Name seven components of a backbone distribution system

cable pathways
ERs that may contain HC (FD), IC (BD), or MC (CD)
TRs that contain HC (FD)
TEs that contain HC (FD)
Entrance Facility (EF)
Transmission Media
Misc Support Facilities

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Which component of the backbone distribution system provides routing space for cables?

Cable Pathways

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Which component of a backbone distribution system usually houses the Main Cross-Connect (MC)?

Equipment Room (ER)

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Which component of a backbone distribution system is describer as an enclosed architectural space for housing telecommunications equipment, cable terminations or horizontal cross connect cabling?

Telecom Room (TR)

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Which component of a backbone distribution system is described as a case or housing that may contain telecom equipment, cable terminations or horizontal cross connect cabling?

Telecom Enclosure (TE)

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Which component of a backbone distribution system is described as an entrance to the building that may contain telecom equipment, cable terminations or horizontal cross connect cabling?

Entrance Facility (EF)

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Name the four primary types of transmission media that can be used for backbone cabling

optical fiber
balanced twisted pair
coaxial
wireless

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Name five examples of connecting hardware that can be used as components of a backbone distribution system

connecting blocks
patch panels
patch cords and jumpers
interconnections
cross connections

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Name four examples of misc support materials

cable support hardware
firestop
bonding hardware
protection and security

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What term refers to a group of connectors that allow equipment and backbone cabling to be cross connected to horizontal cabling

HC (FD)
Horizontal Cross-Connect Floor Distributor

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Which component serves as the (optional) connection point between the first level backbone and the second level backbone?

IC (BD)
Intermediate Cross-Connect Building Distributor

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Which component is normally located in the main ER for the cross connection of entrance cables, first level backbone and equipment cables?

MC (CD)
Main Cross-Connect Campus Distributor

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Name the three fundamental cabling topologies

- Star - Ring - Bus

Name the five types of hybrid cabling topologies

- Hierarchical star - Star wire ring - Clustered star - Tree and branch - Mesh

What topology is generally deployed for OSP cabling?

Star

A star topology directly links all buildings requiring connection to the ___

MC (CD)

What is the ideal location for the MC (CD)?

- Colocated with or close to the primary ER - At the center of the buildings served

Name the five advantages associated with using a star topology for campus backbone cabling

- Provide 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 backbone

Name two disadvantages associated with using the star topology for campus backbone cabling

- Introduces single points of failure - Increases cost

What term is used to describe the tree like structure where a trunk and branch relationship exists within a cabling topology?

Hierarchical

True or False The link from the MC (CD) to the IC (BD) may be an interbuilding or an intrabuilding link

True

What type of link is typically found between the IC (BD) and the HC (FD)?

An intrabuilding link

What configuration should the ICT designer consider when the distance from the switch to the last workstation exceeds the transmission limit?

Hierarchical Star

What type of configuration should the ICT designer consider using when available pathways do not allow for all cables to be routed to an MC (CD)?

Two level hierarchical star

Why are ring topologies being used for OSP operations?

Because they can support high bandwidth transport applications

Name three benefits associated with using a ring topology

- Fault tolerant redundant routing - Greater reliability and significantly less cabling downtime - Flexible architecture

What three conditions must be met before a physical ring topology can be considered for connecting the intrabuilding IC (BD)s and MC (CD)s?

- The existing pathways must support it - The primary purpose of the network is optical fiber distributed data interface, SONET, token ring or reverse path ethernet - There is a redundant cable path

When would a physical star/logical ring be used?

- When a physical ring is not possible - When existing cabling will be used as part of the project

Name three factors the ICT Designer will use to determine if a clustered star topology is an appropriate solution

- Electronics - Designers survivablity plans - Transmission budget selected at the MC (CD) and each node site

Name three advantages associated with using a clustered star topology

- Fault tolerant redundant routing at route locations - May reduce design costs for the electronics and cables at the node sites - More efficient network management

What type of topology is a linear configuration?

Bus topology

What will happen if a break occurs along the route of a bus configuration?

All network communications will be lost

What is a common application of the tree and branch topology?

Cable TV operations that use coaxial cabling

Name the two types of mesh network topologies

- Fully connected - Partially connected

Why are fully connected mesh topologies not adopted for most networks?

- Too expensive - Too complex

Where are fully connected mesh topologies commonly used?

In provider and enterprise networks to connect their routers

What formula is used to calculate the number of nodes required for a fully connected mesh topology?

N = X * (X-1) 2 N = number of links X = number of nodes

What is the minimum number if subscribers supported by the OLT?

16 per port

Where is the ONU assumed to be located?

The ONU is assumed to be outside the home

Name three locations where ethernet over PTP balanced twisted pair cable might be a good fit

- Established neighborhoods - Business parks - Multidwelling units (MDU)

Why are load coils used?

To improve the (voice) transmission performance

What is a drawback associated with using load coils?

They increase the insertion loss of the transmission path outside the normal passband range

How many levels of cross connections are permitted in a backbone distribution system?

No more than two

When are direct connections between TRs permitted?

When the backbone distribution system is expected to meet the requirements for a bus or ring topology configuration

What are the two primary design options for building backbone?

- Star - Hierarchical star

What is often the most cost effective transmission medium for data systems?

optical fiber

What is often the most cost effective medium for voice systems?

balanced twisted pair

True or False The MC (CD) shall be co located in the ER with a PBX, security monitoring equipment and other active equipment being served

False. Co locating with the PBX is okay

True or False A building cabling system shall have only one MC (CD)

True

Name four factors to consider when selecting the transmission media to be used in a backbone distribution system

- Flexibility of the medium with respect to supported devices - Required useful life of backbone cabling - Site size and used population - User needs analysis and forecast

What type of multimode fiber is recommended for backbone cabling systems?

OM4 or higher

Name the two most common configurations for Cat5E cable

24 or 22AWG

Name the three categories of balanced twisted pair cable that are specified for multipair backbone cabling

- Category 3/Class C - Category 5E/Class D - Category 6/Class E

Name the two most common configurations for Cat5E cable

- 4 pair - 25 pair

What is the cable length limitation for backbone cable in a voice system?

2625 ft (800m)

What is the length limit for cables between network equipment connections?

328ft (100m)

True or False Optical fiber cables offer immunity to EMI and RFI

True

Whom should the ICT designer contact for guidance if the optical fiber backbone will be used for a unique specification?

The OEM (original equipment manufacturer)

What is the most common type of internal backbone pathway?

Vertically aligned TRs with connecting sleeves or slots

Why is it considered desirable to stack TRs with other mechanical spaces?

Makes more efficient distribution, shorter runs, shorter conduit, easier bonding

Name three types of steel conduit commonly used in backbone distribution

- RMC - IMC - EMT

What is the benefit of specifying the use of RMC with PVC coating for underground pathways?

PVC provides rust resistance

Name two ways IMC differs from RMC

- Thinner wall thickness - Weighs 1/3 less

What is the lightest weight metallic conduit manufactured for use in backbone distribution systems?

EMT (thin wall)

What is the required height for a curb for a slot?

Minimum of 1"

How far are sleeves permitted to extend above floor level?

- Minimum 1" - Maximum 3"

Why should you leave at least 1" between sleeves?

Allow room for bushings

Name two potential consequences of placing sleeves too far from the wall

- Tripping hazard - Too great a cable span from sleeve to backboard/tray

Per the TDMM, what is the baseline requirement for sleeves per floor?

Four 4" sleeves plus one 4" sleeve for each 40000 sqft of useable floor space

What is the maximum number of rows of sleeves that should be used?

Two whenever possible

True or False Slots should be designed to have the widest depth permitted?

False

Who is responsible for approving the location and configuration of slots?

Structural Engineer

Who is typically responsible for directing cable shaft requirements?

Building Managers

True or False Backbone cable pathways are permitted in elevator shafts

False

Whom should the ICT designer consult for information about the maximum vertical rise distance of a cable?

Manufacturer

Whom should the ICT designer consult when questions arise about floor penetrations?

Structural engineer

Name three potential negative consequences of cable that has been installed without the proper support

- Slippage between core and sheath - Stretching of copper conductors - Broken cable can block pathways

How many cable ties should be used per floor to secure a backbone cable to a vertical steel support?

Minimum of three

What is optical fiber strand count?

The number of optical fibers installed in the cable plant

What is the most common application for optical fiber backbone cabling?

Multiplexed transmission

Name four reasons to include spare optical fibers when installing backbone cabling

- Maintenance - Redundancy - Segregated applications - Future applications

Name the two mounting methods for indoor backbone cabling hardware

- Rack mounted - Wall mounted

Name four locations where rack mount hardware is typically used

- Data Centers - Equipment Rooms (ER) - Computer Rooms - Telecom Rooms (TR)

When is wall mounted hardware used for a distribution system?

When rack space is not available or equipment must be wall mounted

Name three design factors to consider for indoor hardware

- Splicing hardware - Terminating hardware - Patch panels

Where is indoor hardware most commonly used in a backbone distribution system?

In cable terminations

Name three factors used to determine splicing hardware

- Mounting requirements - Optical fiber count - Splicing method

Name four factors that must be know in order to specify terminating hardware

- Location - Cable type - Termination method - Copper pair count or fiber strand count

Name two factors used to determine how much space is needed for a patch panel

- Number of links terminated - Space needed for growth

What is the benefit of interconnecting the cable plant to the applications via patch cords?

Minimizes accidental damage to backbone cable

What is the purpose of EFM?

To specify the functionality required for the subscriber access network

Why is the first mile significant?

It is the critical connection between business and residential users and the public network

TDMM Chapter 4 Flashcards

(104 cards)