Self-Test Vol. 1 Unit 5

Question 1

What is the internet?

Answer 1

A network of networks; a series of private computer networks connected to each other.

Question 2

What is the name for networks that use the same software and protocols as the public internet, but exist as a portion of an entity’s private network?

Answer 2

Intranet

Question 3

What term describes a group of computers and devices that share a common communication line and resources in a small geographical area?

Answer 3

LAN

Question 4

What type of network interconnects several local area networks by bridging them with backbone lines?

Answer 4

MAN

Question 5

What is the name for a network connected between two cities?

Answer 5

WAN

Question 6

Primary addressing in WLANs is achieved by using what type of address?

Answer 6

MAC

Question 7

List the advantages to using WLAN?

Answer 7

Mobility, ease of installation, and lower costs

Question 8

List each of the IEEE wireless standards.

Answer 8

802.11 a/b/g/n

Question 9

The 802.11n standard operates at what frequency?

Answer 9

2.4GHz and 5 GHz

Question 10

What network provides a private tunnel through the Internet?

Answer 10

VPN

Question 11

What type of configuration does the Air Force use for most VPN traffic?

Answer 11

Gateway-to-gateway

Question 12

What is a physical topology?

Answer 12

A map or description of the layout of the network media that interconnects the device on a network.

Question 13

What is a logical topology?

Answer 13

The way in which devices communicate and transmit data throughout the network.

Question 14

What is the rule of thumb to distinguish physical from logical topologies?

Answer 14

If you can see if and touch it, it’s physical.

If you cannot see it or touch it, it’s logical.

Question 15

Because a topology affects the network’s capabilites, what is the impact of choosing one topology over another?

Answer 15

Type of equipment the network needs, capabilities of the equipment, growth of the network, and the way the network is managed.

Question 16

What are the advantages of a bus topology?

Answer 16

Inexpensive to install, easy to add more workstations, requires less cable, works well for small networks.

Question 17

What are the disadvantage of a bus topology?

Answer 17

No longer recommended; if backbone breaks, only limited number of devices, difficult to isolate problems, slower access time.

Question 18

What are the advantages of a star topology?

Answer 18

Easy to add more devices, broken cable doesn’t affect entire network, easy to find device, upgradable, most common topology.

Question 19

What are the disadvantages of a star topology?

Answer 19

Requires more media, failure of central hub can bring down network, higher costs.

Question 20

What are the advantages of a ring topology?

Answer 20

Greater speed, no collision, easier to locate problems, no terminators needed.

Question 21

What are the disadvantages of a ring topology?

Answer 21

Requires more cable, break in cable brings network down, adding devices suspends networks, not commonly used.

Question 22

What are the two most common hybrid topologies?

Answer 22

Star-wired ring and star-wired bus

Question 23

What data transport method grew out of the need for a worldwide standard to allow interoperability of information, regardless of the information type or “end-system”?

Answer 23

ATM

Question 24

How many bytes make up the ATM cell, header, and payload?

Answer 24

53 bytes

Question 25

ISDN channels are separated into two sub-channels, list and describe the sub-channels.

Answer 25

Sub-channel B 56 Kbps or 64 Kbps and are used for both voice and data. Each B channel can carry a separate telephone call. The D-channel is a 16 Kbps use to carry call control (or supervisory) information. Ther information on the "D" channel tells the network switches what to do with the traffic on the "B" channels.

Question 26

What the full bandwidth of a T1 line is not needed it can be divided in 64 Kbps increments known as what?

Answer 26

Fractional T-1

Question 27

What Ethernet standard has supplanted Fast Ethernet in wired networks?

Answer 27

GbE (Gigabit Ethernet)

Question 28

Define modems.

Answer 28

A device that modulates signals to encode digital info and demodulates signals to decode the transmitted info.

Question 29

What are the two types of modems used?

Answer 29

Dial-up and dedicated.

Question 30

What is one of the principal functions of a CSU?

Answer 30

To provide a barrier for electrical interference from either side of the unit.

Question 31

What is the main function of a DSU?

Answer 31

To adapt the digital data stream produced by the customer's equipment to the signaling standards of the telephone carrier equipment.

Question 32

What is the primary use for a bridge?

Answer 32

To decrease network congestion and propagates a signal like a repeater.

Question 33

What do LAN switches provide between network devices?

Answer 33

Collision-free, high-speed communication

Question 34

Can a switch connect LANs of different bandwidths? If so, give example.

Answer 34

Yes, through buffering.

Question 35

What type of switching is required when a moving frame from a low-speed LAN to a high-speed LAN?

Answer 35

Store-and-forward switching.

Question 36

What is the fundamental difference between Layer 2 and Layer 3 switching?

Answer 36

The layer at which each forwarding decision is made.

Question 37

Routers operate at which layer of the OSI model?

Answer 37

Layer 3

Question 38

What does a typical router contain?

Answer 38

An internal processor, an OS, memory, I/O jacks for different types of network connectors, and a management console interface.

Question 39

Routers compare metrics to determine optimal routes; these methods differ depending on what?

Answer 39

Depending on the routing algorithm used.

Question 40

What are routing protocols that manage traffic within an autonomous system called?

Answer 40

IGP

Question 41

Name two methods for directing data on the network.

Answer 41

Static and dynamic routing

Question 42

What is static routing?

Answer 42

A technique in which a network admin programs a router to use specific paths between nodes.

Question 43

What is dynamic routing?

Answer 43

Routing that automatically calculates the best path between the two nodes and compiles this info into a routing table.

Question 44

What are the two methods that encryption can be applied?

Answer 44

Link-by-link or an end-to-end basis.

Question 45

What is the most common telephone device used for voice encryption?

Answer 45

STE

Question 46

What are the most common types of all metallic cable used in networks?

Answer 46

Twisted-pair and coaxial

Question 47

Which cable type is associated with the original designs of the Ethernet standard?

Answer 47

Coaxial

Question 48

List and describe the four most common coax cable types.

Answer 48

RG-6, RG-58, RG-8, RG-11

Question 49

What medium is primary carrier for voice telecommunications?

Answer 49

Twisted-pair cable

Question 50

List and describe the categories of twisted pair cable.

Answer 50

CAT 1, CAT 3, CAT 5, CAT 5e, CAT 6, and CAT 6a

Question 51

What three things do an optical communications system require to transport communications?

Answer 51

A light source, a transmitter, and a receiver

Question 52

List the advantages of fiber optic systems over conventional cable systems.

Answer 52

Larger bandwidth, freedom from interference, low cost, and lightweight.

Question 53

Is fiber optic cable immune to EMI?

Answer 53

Yes

Question 54

What is the most common wireless networking standard?

Answer 54

IEEE 802.11