Chapter 3, final exam dec 12

The _________ layer is responsible for routing of messages from the sender to the final destination.

network layer

___________ is not a type of digital signaling technique.

Data rate signaling

Which of the following would be a standard used at the Data Link layer of the Internet or OSI model?

Ethernet

______________ refers to the time it takes for a signal to travel from sender to recipient (highly exaggerated with satellite transmission).

Propagation delay

With which type of digital signaling does the signal always return to zero volts after each bit?

Return-to-zero signaling

A local area network is:

a group of microcomputers or terminals located in the same general area and connected by a common cable (communication circuit) so they can exchange information.

Which of the following is not a function of the data link layer?

specifying the type of connection, and the electrical signals, radio waves, or light pulses that pass through it

Time (non-statistical) division multiplexing differs from frequency division multiplexing because it:

splits the communication circuit vertically (with time slots) instead of horizontally

Inverse multiplexing means:

combining several low speed circuits to enable them to be transmitted across one high speed circuit

Which of the following is not a property of a WAN:

connects a group of computers in a small geographic area such as room, floor, building or campus.

The integration of voice, video, and data communications is also known as __________.

convergence

___________ refers to the spreading of the signal that different parts of the signal arrive at different times at the destination.

dispersion

Which of the following media has the lowest error rates and the highest transmission speeds?

fiber optic cable

The two basic types of media are:

guided and wireless (radiated)

The ability to transmit in both directions, but only in one direction at a time is an example of _______________ transmission.

half-duplex

To get more "bandwidth" in a digital transmission, you must:

increase the range of frequencies available for a transmission

Which of the following media is the least secure?

infrared

____________ transmission is prone to interference from smoke, heavy rain and fog and requires line-of-sight.

infrared

A(n) _________ is a LAN that uses the same technologies as the Internet but is open to only those inside the organization.

intranet

The type of multiplexer that divides the circuit horizontally into different light frequencies that are transmitted simultaneously across many channels is a:

wavelength division multiplexer

A coding scheme that uses 10 bits to represent each character is capable of representing _________ different characters.

1024

When sending four bits at a time using frequency modulation, the number of different frequency levels that would be needed would be _______.

16

The typical range of human hearing is:

20 to 14,000 Hz

How many bits are required to sample an incoming signal 4000 times per second using 64 different amplitude levels?

6

When converting analog voice data to digital signals, Pulse Code Modulation typically samples the incoming voice signal _______ times per second.

8,000

If the highest frequency of a circuit is 10KHZ and the lowest frequency is 900 Hz, the bandwidth available for this circuit is:

9100 Hz

With respect to converting digital data into analog signals, AM stands for:

Amplitude Modulation

____________ refers to the transmission characteristics of the circuit.

logical circuit

Which of the following would be considered a type of wireless media?

microwave

__________ is a line-of-sight type of wireless media.

microwave

____________ refers to changing the shape of the sound wave in different ways to represent a 1 or a 0.

modulation

The acronym, Modem, stands for _________________.

modulator/demodulator

________________ separate channels to reduce interference between channels in frequency division multiplexing.

Guardbands

Which of the following is not a data link layer standard?

HTTP

Which of the following is a term used to group together the physical and data link layers?

Hardware layers

The network layer of the Internet model uses the _____________ protocol to route messages though the network.

IP

Which of the following is not a key advantage of digital transmission?

It permits only low transmission rates.

The earliest type of fiber optic systems were:

Multimode

Which of the following statements is correct?

Serial transmission is slower than parallel transmission.

___________ is an orderly close to a dialogue between end users.

Session termination

Which of the following is not an application layer standard?

T1

A backbone network is:

a high speed central network that connects other networks in a distance spanning up to several miles.

A metropolitan area network is:

a network that spans a geographical area that usually encompasses a city or county area (3 to 30 miles) and that typically uses common carrier circuits.

Digital Subscriber Line:

all of the above

Microwave transmission:

all of the above

The height of a sound wave is called its:

amplitude

In which layer of the Internet model would the HTTP standard be used?

application

Another term for the weakening of a signal over distance is:

attenuation

The _____________ of a circuit determines a circuit's capacity.

bandwidth

Which of the following is a function of the transport layer?

breaking long messages into several smaller messages

The term ______________ refers to high speed communication circuits such as DSL.

broadband communications

Transmission speeds:

differ widely among media

The primary reason for networking standards is to:

ensure that hardware and software produced by different vendors can work together

A(n) _________ is a LAN that uses the same technologies as the Internet but is provided to invited users outside the organization who access it over the Internet.

extranet

Which of the following media can best withstand harsh environmental conditions?

fiber optic cable

Frequency division multiplexing:

operates by dividing the signal into different frequencies

Networks that are designed to connect similar computers that share data and software with each other are called:

peer-to-peer networks

The direction in which the sound wave begins is known as:

phase

Which of the following is a characteristic of sound waves that can be modulated to convert digital data into analog signals?

phase

In which type of modulation is a 1 distinguished from a 0 by shifting the direction in which the wave begins?

phase modulation

Data is physically transmitted from one computer or terminal to another in the ________ layer.

physical

The ____________ layer of the OSI model is responsible for data format translation.

presentation

A(n) _____________ is a set of rules that determine what a layer would do and provides a clearly defined set of messages that software at the layer needs to understand.

protocol

Which is not a function of the physical layer:

providing error-free transmission of data.

____________ is a modulation technique that combines two different amplitude combinations with eight different phase combinations modulation to send four bits per symbol.

quadrature amplitude modulation

When all bits of a character are transferred one after another, the bits are transferred in ___________ mode.

serial

In the Internet model, the application layer corresponds to the ________, layer(s) s of the OSI model.

session, presentation and application

The function of the file server is to:

store data and software programs that can be used by client computers on the network.

_____________ is not a form of modulation used to transform digital data into analog signals.

synchronous time division

The fourth layer of the OSI model is called the __________ layer.

transport

Which layer of the OSI model is responsible for ensuring flow control so that the destination station does not receive more packets that it can process at any given time?

transport Layer

Which layer of the OSI model is responsible for ensuring that all packets sent are received by the destination station by dealing with end-to-end issues?

transport Layer

The _________ layer performs error checking which is redundant with the function of the _________ layer.

transport, data link

The type of media usually installed on homes and businesses by the telephone company is called ____________.

twisted pair