COMPUTER NETWORKING II

Question 1

What are the three modes of data transmission?

Answer 1

• Simplex (Unidirectional transmission) is a single, one-way transmission. Eg mouse and PC
• Half-duplex allows data to flow in one direction at a time. Eg PC and Server
• Full-duplex allows data to flow in both directions at the same time. Eg Mainframe and Mainframe

Question 2

What is a modem?

Answer 2

The word modem is short for modulator-demodulator. Modulation is the name of the process of converting from digital to analog. Demodulation is the process of converting from analog to digital.
• A Modem is an electronic device that connects to the Internet via an ISP.
• Internal modems- Expansion slots
•External modems- USB ports

Question 3

What are hubs and repeaters?

Answer 3

• Hub: Central device that connects all of the devices on the network
• Repeater: Amplifies signals along a network

Question 4

What is a bridge

Answer 4

• A bridge divides a network into two or more segments and tracks which device is on each segment
• has the intelligence to determine if an incoming frame is to be sent to a different segment or dropped. A bridge has two ports.

Question 5

What is a switch?

Answer 5

(multiport bridge) has several ports and record MAC addresses for each device
connected to the switch.
• Data is sent to a specific device if the MAC address of that device is in the MAC address table

Question 6

What is a router?

Answer 6

Devices that connect entire networks to each other. They use IP addresses to forward packets to other networks.
• A router can be a computer with special network software installed or can be a device built by network
equipment manufacturers.
• Routers contain tables of IP addresses
along with optimal routes to other
networks.

Question 7

What are Wireless Access Points (WAP)

Answer 7

• Provide network access to wireless devices such as laptops and PDAs.
• Use radio waves to communicate with radios in computers, PDAs, and other wireless access points.
• Have limited range of coverage

Question 8

What are the types of Network topologies?

Answer 8

1. Bus Network
2. Ring Network
3. Star Network
4. Tree network
5. Mesh network

Question 9

Describe bus networks

Answer 9

each device is connected to a common cable called a bus or backbone, and all communications travel
along this bus.

Question 10

Describe Ring networks

Answer 10

• each device is
connected to two
other devices, forming
a ring.
• When a message is
sent, it is passed
around the ring until it
reaches the intended
destination.

Question 11

Describe Star networks

Answer 11

• each device is connected directly
to a central network switch. Whenever a node sends a message, it is routed to the switch, which then passes the
message along to the intended recipient.
• The star network is the most widely used network topology
today.

Question 12

Describe Tree networks

Answer 12

• each device is connected to a
central node, either directly or through one or more other devices.
• The central node is connected to two or more subordinate nodes that in turn are connected to other subordinate nodes, and so forth, forming a treelike structure.
• This network, also known as a hierarchical network, is often
used to share corporatewide data.

Question 13

Described Mesh Networks

Answer 13

• the mesh network requires that each node have more
than one connection to the other nodes.
• Connects all devices to each other.
• If a path between two
nodes is somehow
disrupted, data can be
automatically rerouted
around the failure using another path.

Question 14

What are the types of organizational networks?

Answer 14

1. Intranet

2. Extranet

Question 15

What is Intranet?

Answer 15

a private network within an organization that resembles the Internet.
• The main purpose of an intranet is to share
company information and computing
resources among employees
• Like the public Internet, intranets use
browsers, websites, and web pages. Typical applications include electronic telephone directories, e-mail addresses, employee benefit information, internal job openings, and much more.

Question 16

What is extranet?

Answer 16

A private network that connects more than one organization.
• An extranet can be viewed as part of a company’s intranet that is extended to users outside the company
• Many organizations use Internet technologies to allow
suppliers and others limited access to their networks. The purpose is to increase efficiency and reduce costs.

Question 17

What is an IP address

Answer 17

An IP address (Internet Protocol Address) is a unique number that is used to identify a network device and is represented as a 32-bit binary number, divided into four octets (groups of eight bits):
•Example:
10111110.01100100.00000101.00110110
• The above IP address is also represented in the following
dotted decimal format.
•i.e. 190.100.5.54

Question 18

What is internet protocol?

Answer 18

A protocol is a set of rules. Internet protocols govern communication within and between computers on a network.

Question 19

What are the main functions of protocols?

Answer 19

• Identifying errors
• Compressing data
• Deciding how data is to be sent
• Addressing data
• Deciding how to announce sent and received data

Question 20

What is the use of https?

Answer 20

hypertext transfer protocol secure, is widely used to protect the transfer of sensitive information

Question 21

What is the use of FTP?

Answer 21

file transfer

Question 22

What is the use of SMTP?

Answer 22

The server that holds your e-mail uses SMTP, or simple mail transfer
protocol, to exchange mail with other e-mail servers throughout the
world.

Question 23

What is the use of TCP/IP?

Answer 23

(transmission control protocol/Internet
protocol)
Devices and computers connected to the Internet use a protocol
suite called TCP/IP to communicate with each other.

Question 24

What is identification in TCP/IP?

Answer 24

Similar to the way a postal service uses addresses to deliver
mail, the Internet uses IP addresses to deliver e-mail and to
locate websites.

Question 25

What is DNS?

Answer 25

Because these numeric addresses are difficult for people to remember a system was developed to
automatically convert text-based addresses to numeric IP addresses. This system uses a domain name server (DNS). For
example, whenever you enter a URL, say www.mhhe.com, a DNS converts this to an IP address before a connection can be made.

Question 26

What is packetization in TCP/IP

Answer 26

Before the message is
sent, it is reformatted or broken down into small parts called packets.
• Each packet is then sent separately over the Internet, possibly traveling different routes to one common destination.
• At the receiving end, the packets are reassembled into the correct order

Question 27

What are three technologies to ensure network security?

Answer 27

– firewalls,
– intrusion detection systems,
– virtual private networks.

Question 28

Describe a firewall

Answer 28

• A firewall is a network security system that monitors,
and controls incoming and outgoing network traffic based on predetermined security rules.
• Most use software or a special computer called a proxy server.
• All communications between the company’s internal networks and the outside world pass through this server. By evaluating the source and the content of
each communication, the proxy server decides whether it is safe to let a particular message or file pass into or out of the organization’s network.

Question 29

Describe Intrusion detection systems (IDS)

Answer 29

• work with firewalls to protect an organization’s network.
• These systems use sophisticated statistical
techniques to analyze all incoming and
outgoing network traffic.
• Using advanced pattern matching and
heuristics, an IDS can recognize signs of a
network attack and disable access before
an intruder can do damage

Question 30

Describe Virtual private networks (VPN)

Answer 30

• create a secure private connection between a remote user and an organization’s internal network.
• Special VPN protocols create the equivalent of a dedicated line between a user’s home or laptop computer and a company server.
• The connection is heavily encrypted, and,
from the perspective of the user, it appears
that the workstation is actually located on the
corporate network.