Ch14 - Physical Security

Question 1

Facility Concerns

Answer 1

1. Crime Rate
2. Flood Zone (or other natural disasters stats)
3. How Long It Takes Emergency Services to Reach a Facility?

Question 2

Motion Sensors

Answer 2

1. Closed-circuit sensor
2. Pressure mat sensor
3. Proximity sensor
4. Photoelectric sensor

Question 3

Closed-circuit sensor

Answer 3

With a closed-circuit sensor, an electrical
circuit exists that, when broken, triggers the alarm, indicating that someone is in the area. This is commonly used in windows (with tiny wires) so that if the window is smashed, the circuit is broken and the alarm signals.

Question 4

Pressure mat sensor

Answer 4

You can also use pressure mats that are activated after working hours so that if an intruder enters the facility and walks on the material, then the alarm will go off.

Question 5

Proximity sensor

Answer 5

With a proximity sensor, the sensor emits a magnetic field that it monitors. When someone approaches, the motion of the intruder changes the field’s frequency. The system detects this, and it sets off the alarm. ** This kind of motion sensor is prone to many false alarms. **

Question 6

Photoelectric sensor

Answer 6

With a photoelectric sensor, a beam of light is emitted from a transmitter to a receiver. When an intruder breaks the beam of light, it trips the alarm.

Question 7

Access Systems - Fail-safe

Answer 7

A fail-safe device responds by not doing anything to cause harm when the failure occurs. For example, if a lock fails, it defaults to being unlocked so that people can enter or exit. This is also known as fail-open because the door will default to being open.

Question 8

Access Systems - Fail-secure

Answer 8

A fail-secure device responds by making sure that the device is using a secure state when a failure occurs. For example, if a
lock fails and it is a fail-secure lock, it will default to a locked state. This is also known as fail-close because the door will default to being locked and cannot be opened.

Question 9

Heating, Ventilation, and Air Conditioning (HVAC)

Answer 9

Heating, Ventilation, and Air Conditioning (HVAC) is a system to provide or reduce heat, humidity, and outdoor air. The goal of the HVAC system is to provide climate control to help maintain quality conditions in the workplace.

The HVAC controls the temperature and the humidity within the building. This helps computer systems run optimally.

The temperature in the building should be around 70 to 74 degrees Fahrenheit. If the temperature gets too warm, it could cause the systems to overheat and shut down.

The humidity levels should be between 40 and 60 percent. If you have humidity levels less than 40 percent, then you could experience a lot of electrostatic discharge (ESD). ESD can destroy computer components and computer chips. Humidity levels above 60 percent can corrode computer components.

Question 10

Hot and cold aisles

Answer 10

To keep the systems cool in a data center, the racks are configured in a hot/cold aisles configuration. This configuration involves breaking the racks into rows with the fronts of the racks facing each other to create cold aisles, and …

The backs creating the hot aisles (hot air goes out the back of the racks). The HVAC
airflow would be designed to take the warm air from the hot aisle and exhaust it outside, away from the data center, while bringing in new cool air in the cold aisle from the front of the racks.

Question 11

Sprinkler Systems - Wet-pipe

Answer 11

With the wet-pipe system, water is in the pipe at all times and ready to be released. This allows for a quick release of water when a certain temperature is reached, but the drawback is that the pipes could freeze.

Question 12

Sprinkler Systems - Dry-pipe

Answer 12

The dry-pipe system has water sitting in a reservoir and not in the pipe. This allows for a short delay, giving you time to turn off the valve if needed before water is released. This type of sprinkler system is a good selection in colder climates because, with no water in them, the pipes do not freeze.

Question 13

Sprinkler Systems - Pre-action system

Answer 13

With a pre-action system, a head link on the sprinkler has to be melted in order for the water to be released. This gives you the opportunity to put the fire out with an extinguisher before the sprinkler system is used.

Question 14

Different Classes of Fires

Answer 14

1. Class A
2. Class B
3. Class C
4. Class D

Question 15

Fire: Class A

Answer 15

Class A fires are known as common combustible fires and include the burning of wood, paper, cloth, or plastic. To put out these fires, you should have a suppression method that uses water or soda acid (Class A fire extinguisher).

Question 16

Fire: Class B

Answer 16

Class B fires are considered liquid fires and include the burning of gas, oils, tars, solvents, and alcohol. With these types of fires, you cannot use water; instead, you must take the oxygen away by using CO2 or FM-200 extinguishers.

Question 17

Fire: Class C

Answer 17

Class C Class C fires include the burning of electrical components and equipment. In the past, these fires were extinguished with Halon gas, CO2, or a nonconductive extinguishing agent such as FM-200. Using Halon is no longer recommended because it is ozone depleting, but CO2 and FM-200 extinguishers are still used and can be used on Class B or Class C fires.

Question 18

Fire: Class D

Answer 18

Class D fires include the burning of combustible metals such as magnesium and sodium and require a suppression method that uses dry chemicals.