# Chapter 18 - Data Centers Flashcards

1
Q

ANSI/TIA-569-E, Telecommunications Pathways and Spaces, discusses total maximum pathway fill as ___ percent of the total available pathway cross-sectional area.

a. 40
b. 50
c. 60
d. 65

A

b. 50

p 18-17

Total maximum pathway fill as 50 percent of the total available pathway cross-sectional area calculated as the sum of the cross-sectional area of every cable within that pathway compared with the available cross-sectional pathway area, with a maximum pathway depth of 150 mm (6 in).

2
Q

The ANSI/TIA standard for data centers identifies three tiers of distributors for the hierarchical structured cabling system, as follows:

a. Main cross-connect (MC), zone cross-connect (ZC), and horizontal cross-connect (HC)
b. Main cross-connect (MC), intermediate cross-connect (IC), and zone cross-connect (ZC)
c. Main cross-connect (MC), intermediate cross-connect (IC), and horizontal cross-connect (HC)

A

c. Main cross-connect (MC), intermediate cross-connect (IC), and horizontal cross-connect (HC)

p 18-15

Data center topology from ANSI/TIA-942-B is shown in Figure 18.3

3
Q

When considering the threat to sensitive or mission-critical data, it is easy to envision ___ as the key threats. The reality is that ___ provide a higher likelihood of catastrophic loss of data.

a. Malicious acts, physical threats
b. Physical threats, malicious acts

A

a. Malicious acts, physical threats

p 18-25

When considering the threat to sensitive or mission-critical data, it is easy to envision hacking, identity theft, and corporate espionage as the key threats. The reality is that physical threats (e.g., natural disasters, interruption of utilities, equipment failure, weather, human error) provide a higher likelihood of catastrophic loss of data

4
Q

The data center’s overall class rating is equal to the ___ rating component across all portions of its infrastructure.

a. Lowest
b. Highest

A

a. Lowest

p 18-4

For example, a data center may be rated class F3 for electrical but class F2 for mechanical. However, the data center’s overall class rating is equal to the lowest rating or weakest component across all portions of its infrastructure.

5
Q

Availability Class F3 has a targeted availability of ___ %:

a. Less than 99
b. 99
c. 99.99
d. 99.999

A

c. 99.99

p 18-7

6
Q

Availability Class F2 has an annual maintenance window of ___ hours

a. more than 400
b. 100 to 400
c. 50 to 99
d. 0 to 49

A

c. 50 to 99

p 18-7

7
Q

The ANSI/TIA-942-B minimum standard for category backbone cabling is Cat ___

a. 3
b. 5e
c. 6
d. 6A

A

a. 3

p 18-11 Table 18.1

For backbone cabling per ANSI/TIA-568.2-D: category 3, 5e, 6, or 6A, with category 6A or 8 recommended

8
Q

In keeping copper communications cabling properly separated from power distribution is one design approach. One solution to maintain adequate separation
is to place power cabling in the ___ aisles.

a. Hot
b. Cold

A

b. Cold

p 18-21

One solution to maintain adequate separation is to place telecommunications cabling in the hot aisles and power cabling in the cold aisles. If the power cables are in the cold aisles, the design should avoid impeding air flow through tile perforations.

9
Q

The maximum optical fiber patch cord pileup within a pathway as no more than ___ in depth.

a. 1
b. 2
c. 4
d. 6

A

b. 2

p 18-17

The maximum optical fiber patch cord pileup within a pathway as no more than 50 mm (2 in) depth, regardless of the size of each individual optical fiber patch cord or available pathway cross-sectional area.

10
Q

In the data center environment, the separation between balanced twisted-pair cable and power distribution in pathways is generally ___ ft separation.

a. 1
b. 2
c. 3
d. 4

A

b. 2

p 18-17

The requirement is generally ≈600 mm (2 ft) separation for large quantities of electrical branch circuits or any number of electrical feeder circuits.

Additionally, ≈12.5 mm (5 in) separation is required between balanced twisted-pair cables and fluorescent lamps and associated fixtures.

Also see p 2-38 Table 2.7. Same specs

11
Q

The most frequently benchmarked performance metric for data centers is the amount of delay when accessing stored data or processing capabilities.

a. True
b. False

A

b. False

p 18-24

The most frequently benchmarked performance metric for data centers is the percentage of time with total access to stored data or processed capabilities.

12
Q

Within equipment racks and cabinets, the planned capacity of the cable management should be ___ percent by cross-sectional area of the cables.

a. 40
b. 50
c. 60
d. 65

A

a. 40

p 18-37

The planned capacity of the cable management should be 40 percent by cross-sectional area of the cables. Routing of cabling and the cabinet should not block
airflow into and out of the equipment and should provide adequate access for servicing equipment, including replacement of hot-swappable components (e.g., line cards, fan trays).

13
Q

___ is the long-term average of time that a system is in service and is satisfactorily performing its intended function.

a. Mean time to failure
b. Fault tolerance
c. Reliability
d. Availability

A

d. Availability

p 18-28

14
Q

___ focuses on the probability that a given system will operate properly without failure for a given period of time.

a. Mean time to failure
b. Fault tolerance
c. Reliability
d. Availability

A

c. Reliability

p 18-28

15
Q

Data center telecommunications spaces include the equipment room.

a. True
b. False

A

b. False

p 18-9

```Data center telecommunications spaces include the:
• Building entrance facility
• Main distribution area (MDA)
• Intermediate distribution area (IDA)
• Horizontal distribution area (HDA)
• Zone distribution area (ZDA)
• Equipment distribution area (EDA)```
16
Q

When evaluating data center facility availability classes, _____ is a major factor in determining system reliability.

a. Mean time to repair (MTTR)
b. Mean time between failures (MTBF)

A

b. Mean time between failures (MTBF)

p 18-5

In bullet “Quality control”, MTBF is a major factor in determining system reliability, higher quality components with lower failure rates will produce more reliable systems.

17
Q

The critical components in a data center requires “Premium quality” in Quality control for Class(es)

a. F1
b. F3 and higher
c. F2 and higher
d. F2 and F3

A

d. F2 and F3

p 18-7

18
Q

Adding redundant components to data center infrastructure _____ the efficiency of the data center.

a. Does not affect
b. Increases
c. Decreases

A

c. Decreases

p 18-4

Redundancy increases both fault tolerance and maintainability. However, adding redundant components in case of failures decreases the efficiency of the data center and increases the losses.

19
Q

The CENELEC and ISO/IEC standards for data centers specifies 734-type and 735-type coaxial cables for E1 and E3 telecommunications circuits.

a. True
b. False

A

b. False

p 18-12

ANSI/TIA-942-A lists 75-ohm TNC or BNC for 734 and 735 coaxial cables with BNC recommended. No coax in CENELEC and ISO/IEC standards.

20
Q

The CENELEC and ISO/IEC equivalent of the consolidation point specified in the ANSI/TIA standard for data centers is called the:

a. Equipment distributor
b. Zone outlet
c. Zone distribution point (ZDP)
d. Local distribution point (LDP)

A

d. Local distribution point (LDP)

p 18-10 Table 18.1

ANSI/TIA-942-B = Zone outlet or consolidation point in the ZDA.

CENELEC EN 50173-5 & ISO/IEC 11801-5 equivalent is LDP

21
Q

Something a person _____ is an optional and less distinct authentication factor used for access control.

a. Gives
b. Knows
c. Has
d. Does

A

d. Does

p 18-27

It is generally accepted that there are three primary authentication factors with an additional optional factor. They are:
• Something a person knows (e.g., passwords and personal identification numbers).
• Something a person has (e.g., keys, cards, tokens).
• Something a person is (e.g., some physical characteristic [biometrics]).
• Something a person does (optional and less distinct authentication factor).

22
Q

When planning the design of data center telecommunications cabling, note that support for 40G Ethernet over 50/125 mm 850 nm laser-optimized multimode optical fiber will require _____ optical fibers per circuit.

a. 16
b. 12
c. 8
d. 4

A

c. 8

p 18-35

40G uses 2 or 8 multimode optical fibers;

• 50G uses 2 multimode optical fibers.
• 100G will use 4, 8, or 20 multimode optical fibers.
• 200G will use 8 multimode optical fibers.
• 400G will use 8 or 32 multimode optical fibers.
23
Q

The CENELEC and ISO/IEC standards for data centers specify angled LC connectors for singlemode fiber terminated at the:

a. Local distribution point (LDP)
b. Main distributor (MD)
c. Equipment outlet (EO)
d. External network interface (ENI)

A

d. External network interface (ENI)

p 18-12 Table 18.1

Angled LC for SMF at ENI.

LC-PC for 1 or 2 SMF at EO and MPO for 3+ MMF at EO MPO for 3+ MMF at EO per EN 50173-1 for optical fiber per ISO/IEC 11801-1 for optical at other locations

24
Q

It is generally accepted that there are ___ primary authentication factors with an additional optional factor.

a. Two
b. Three
c. Four

A

b. Three

p 18-27

They are:
• Something a person knows (e.g., passwords and personal identification numbers).
• Something a person has (e.g., keys, cards, tokens).
• Something a person is (e.g., some physical characteristic [biometrics]).
• Optional - Something a person does (optional and less distinct authentication factor).

25
Q

The CENELEC and ISO/IEC standards for data centers specify angled LC connectors for singlemode fiber terminated at the:

a. Local distribution point (LDP)
b. Main distributor (MD)
c. Equipment outlet (EO)
d. External network interface (ENI)

A

d. External network interface (ENI)

p 18-12

Angled LC for SMF at ENI

26
Q

The CENELEC and ISO/IEC standards for data centers specify a hierarchical cabling topology in which local distribution points (LDPs) are used to link:

a. Intermediate distributors (IDs) to zone distributors (ZDs)
b. Horizontal distributors (HDs) to equipment outlets (EOs)
c. Zone distributors (ZDs) to horizontal distributors (HDs)
d. Equipment outlets (EOs) to zone distributors (ZDs)

A

d. Equipment outlets (EOs) to zone distributors (ZDs)

p 18-14 Figure 18.2

27
Q

The ANSI/TIA-569-E standard for telecommunications pathways and spaces allows for a maximum depth of _____ for horizontal cable pathways.

a. 300 mm (12 in)
b. 200 mm (8 in)
c. 150 mm (6 in)
d. 100 mm (4 in)

A

c. 150 mm (6 in)

p 18-17

It is calculated as the sum of the cross-sectional area of every cable within that pathway compared with the available cross-sectional pathway area, with a maximum pathway depth of 150 mm (6 in).

28
Q

When planning the design of data center telecommunications cabling, support for 50G Ethernet over multimode fiber will require _____ optical fibers per circuit.

a. 8
b. 6
c. 4
d. 2

A

d. 2

p 18-35

40G uses 2 or 8 multimode optical fibers;
50G uses 2 multimode optical fibers.
100G will use 4, 8, or 20 multimode optical fibers.
200G will use 8 multimode optical fibers.
400G will use 8 or 32 multimode optical fibers.

29
Q

Data center facility survivability refers to reducing the risk of downtime by protecting against _____ events.

a. Internal
b. External

A

b. External

p 18-5

Survivability refers to reducing the risk of downtime by protecting against external events such as physical forces, security breaches, and natural disasters.

30
Q

Each data center facility availability class is defined in terms of four areas of concern, which are:

a. Fault tolerance, maintainability, operational readiness, and susceptibility to natural disasters
b. Redundancy, fault tolerance, survivability, and quality control
c. Reliability, availability, meant time between failure (MTBF), and mean time to repair (MTTR)
d. Component redundancy, system redundancy, survivability, and quality control

A

d. Component redundancy, system redundancy, survivability, and quality control

p 18-5

31
Q

The CENELEC and ISO/IEC standards for data centers identify three tiers of distributors for the hierarchical structured cabling system, as follows:

a. Main distributor (MD), horizontal distributor (HD), and zone distributor (ZD)
b. Main distributor (MD), intermediate distributor (ID), and horizontal distributor (HD)
c. Main distributor (MD), intermediate distributor (ID), and zone distributor (ZD)

A

c. Main distributor (MD), intermediate distributor (ID), and zone distributor (ZD)

p 18-10 Table 18.1

32
Q

The ANSI/TIA-569-E standard for telecommunications pathways and spaces allows for a maximum depth of _____ for horizontal cable pathways.

a. 300 mm (12 in)
b. 200 mm (8 in)
c. 150 mm (6 in)
d. 100 mm (4 in)

A

c. 150 mm (6 in)

p 18-17

ANSI/TIA-569-E, Telecommunications Pathways and Spaces, discusses total maximum pathway fill as 50 percent of the total available pathway cross-sectional area calculated as the sum of the cross-sectional area of every cable within that pathway compared with the available cross-sectional pathway area, with a maximum pathway depth of 150 mm (6 in).