Comutação de Pacotes

Question 1

Identify the five components of a data communications system.

Answer 1

Sender, Receiver, Transmition Medium, Message and Protocol

Question 2

What are the three criteria necessary for an effective and efficient network?

Answer 2

Performance, reliability and security.

Question 3

What are the two types of line configuration?

Answer 3

Types of connection are point-to-point and multipoint.

Question 4

What is the difference between half-duplex and full-duplex transmission modes?

Answer 4

In half-duplex transmission, only one entity can send at a time. In Full-duplex transmission, both can sent at same time.

Question 5

For n devices in a network, what is the number of cable links required for a mesh, ring, bus, and star topology?

Answer 5

mesh: n*( n - 1 )/2
ring: n - 1
bus: one backbone and n drop lines
star: n

Question 6

Why are standards needed?

Answer 6

Standards are needed to create and maintain an open e competitive marker for manufactures, to coordinate protocol rules, and thus guarantee compatibility of data communications technologies.

Question 7

A color image uses 16 bits to represent a pixel. What is the maximum number of different colors that can be represented?

Answer 7

With 16 bits, we can represent up to 2¹⁶ differents colors.

Question 8

Draw a hybrid topology with a star backbone and three ring networks.

Answer 8

Question 9

Performance is inversely related to delay. When you use the Internet, which of the following applications are more sensitive to delay?

a. Sending an e-mail
b. Copying a file
c. Surfing the Internet

Answer 9

Surfing the internet is a very sensitive to delay.

Question 10

Compare the telephone network and the Internet. What are the similarities? What are the differences?

Answer 10

The telephone network was originally designed for voice communication. The Internet was designated for data communication. The two networks are similar in fact that both are made of interconnections of small networks. The telephone network, is mostly a circuit-switched network. The Internet is mostly a packet-switched network.