Week 3

Question 1

What does the ANSI/TIA-568 Commercial Building Wiring Standard describe?

Answer 1

the ANSI/TIA-568 Commercial Building Wiring Standard describes the best way to install networking media to maximise performance and minimise upkeep

Question 2

What is an entrance facility (EF)?

Answer 2

An entrance facility is a location where the incoming network (such as Internet) connects with the school or corporate network.

Question 3

What is a demarc?

Answer 3

A demarc (demarcation point) is the device that marks where a telecommunications service provider’s network ends and the organisation’s network begins

Question 4

What is an MDF?

Answer 4

A main distribution frame is the centralised point of interconnection for an organisation’s LAN or WAN(also called MC or main cross connect)

Question 5

What is a data room?

Answer 5

A data room is an enclosed space that holds network equipment (also called data closet, data centre, equipment room, or telecommunications room)

Question 6

What is a rack?

Answer 6

A rack holds various network equipments

Question 7

What is a patch panel?

Answer 7

A patch panel is a panel of data receptors which can be mounted to a wall or a rack (A patch panel provides a central termination point when many patch cables converge in a single location)

Question 8

What is VoIP?

Answer 8

VoIP (Voice over IP) is the use of any network to carry voice signals using TCP/IP protocols.

Question 9

What is an IDF?

Answer 9

An IDF (intermediate distribution frame) provides an intermediate connection between the MDF and end-user equipment on each floor and in each building

Question 10

What outlets does the ANSI/TIA standard require wall jacks to have?

Answer 10

The ANSI/TIA standard requires wall jacks to have one voice and one data outlet.

Question 11

What are the two different types of racks?

Answer 11

• Two post
• Four post

Question 12

What method is used to cool racks in data centres containing multiple racks?

Answer 12

A hot aisle/cold aisle layout is used. Cool air is pulled from the vents in the floor or from low-lying wall vents into the rows of racks.

Question 13

What is a patch cable?

Answer 13

A patch cable is a relatively short length of cabling with connectors at both ends

Question 14

What is horizontal cabling?

Answer 14

Horizontal cabling is cabling that connects workstations to the closest data room and to switches housed in the room

Question 15

What is backbone cabling?

Answer 15

Backbone cabling consists of cables or wireless links that provide interconnection between the entrance facility and MDF and between MDF and IDFs

Question 16

What is the maximum amount of cable you can leave exposed when terminating a cable?

Answer 16

Don’t leave more than 1 inch of exposed cable before a termination.

Question 17

What is bend radius?

Answer 17

Bend radius is the radius of the minimum arc into which you can loop a cable without impairing data transmission. Do not exceed the cable’s prescribed bend radius

Question 18

What is continuity?

Answer 18

Continuity refers to a cable segment being able to transmit data reliably. Use a cable tester to verify a cable segment works

Question 19

What are cable coverings and conduits?

Answer 19

Cable coverings and conduits are used to cover exposed cables. It is good practice to avoid laying cables across the floor

Question 20

What are EMI sources?

Answer 20

EMI sources produce electromagnetic interference such as fluorescent lights. Cables should be installed at least 3 feet away from EMI sources.

Question 21

What is plenum cabling?

Answer 21

Plenum cabling is used when cabling is required to run above ceiling tiles or below subflooring

Question 22

What is the usual standard of Ethernet?

Answer 22

Ethernet II

Question 23

What does ethernet add to a payload?

Answer 23

Ethernet adds a header and a trailer to the payload. This creates a frame around the payload. The header and the FCS make up the 18-byte “frame” around the data

Question 24

What amount of bytes may the data portion of an Ethernet frame contain?

Answer 24

The data portion of an Ethernet frame may contain from 46 to 1500 bytes

Question 25

What amount of bytes may the data portion of an Ethernet frame contain?

Answer 25

The data portion of an Ethernet frame may contain from 46 to 1500 bytes

Question 26

What are the two sub-layers of the data link layer?

Answer 26

• Logical link control (LLC): The upper portion of the data link layer that identifies the type of message (the only LLC sublayer function in an Ethernet II frame) and handles multiplexing, flow and error control, and reliability (requires other types of Ethernet frames).
• Media Access Control (MAC): The lower portion of the data link layer that identifies the destination and source MAC addresses, includes the message, and provides the checksum in the frame’s trailer.

Question 27

What is the structure of an ethernet frame

Answer 27

1. Preamble and SFD (8 bytes)
2. Header (6 bytes, 6 bytes, 2 bytes)
3. Data (46-1500 bytes)
4. Trailer (4 bytes)

Question 28

What is MTU?

Answer 28

The maximum transmission unit (MTU) is the largest size, in bytes, that routers in a messages path will allow at the network layer (1500 bytes for ethernet, considered the internet standard)

Question 29

What are the three functions of ethernet?

Answer 29

1. Transmitting and receiving data frames
2. Decoding data frames and checking them for valid MAC addresses
3. Detecting errors within data frames or on the network
   (Note that Ethernet performs error detection but NOT error correction, any frame with an incorrect checksum is an error, any frame under 64 bytes in length is an error)

Question 30

What happens when multiple nodes attempt to communicate at the same time?

Answer 30

The signals will interfere and this is called a collision

Question 31

What is used for controlling access to a shared medium?

Answer 31

CSMA/CD

Question 32

What is flooding?

Answer 32

Flooding is when a switch sees an unknown destination MAC address, it forwards the frame on all ports aside from the source port.

Question 33

What is a bridging table?

Answer 33

A bridging table is a table where switches associate interfaces (ports) to MAC addresses