CET4483 - Data Communication

Data communications permits the transmission of all types of data and information. Social media has become a big part of this data transfer, and it is estimated that it will continue to grow at large rates. According to Cisco there will be as much as __________ Terabytes transferred over the Internet daily. 30,000 30,000,000 300,000 3,000,000

3,000,000

_____________ can be thought of as dividing the circuit horizontally. Statistical time division multiplexing Frequency division multiplexing Wavelength division multiplexing Time division multiplexing Statistical frequency division multiplexing

Frequency division multiplexing

The protocol that makes it possible for a Macintosh web browser to be able to retrieve a Web page from a Microsoft Web server is called the _____________________. Hyperlink Transfer Protocol Internet Message Access Protocol Simple Mail Transfer Protocol File Transfer Protocol Hypertext Transfer Protocol

Hypertext Transfer Protocol

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

Phase

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

Phase

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? session transport physical presentation application

transport

A pathway or circuit can be made of copper wire, fiber optics and ________. carbon strand carbon plenum wireless none of the above

wireless

________ is the process of sending a signal to a client that gives its permission to transmit or asks it to receive. Pooling Contention Carrier sense CRC Polling

Polling

______________ refers to the time it takes for a signal to travel from sender to recipient (highly exaggerated with satellite transmission). Raindrop attenuation Multimode index Propagation delay Saturation effect Line-of-sight effect

Propagation delay

___________ is an orderly close to a dialogue between end users. Session termination Frame overhead Message encryption Packet encapsulation Physical bits

Session termination

The most commonly used e-mail standard is: Post Office Protocol Simple Mail Transfer Protocol Telnet X.400 CMC

Simple Mail Transfer Protocol

Which form of multiplexing divides the circuit into various time slots, and the devices take turns transmitting? TDM IDM PDM FDM

TDM

Which of the following is not true about Telnet? Telnet requires an application layer program on the client computer and an application layer program on the server or host computer. Telnet was designed in the early days of the Internet. Telnet poses no security threat. Keystrokes are sent over the network in clear text. One program that conforms to the Telnet standard is PuTTY.

Telnet poses no security threat.

Which of the following is not a type of synchronous protocol? Ethernet VT100 HDLC SDLC PPP

VT100

The standards H.320, H.323, and MPEG-2 are commonly used with Email Telnet Videoconferencing IM Microsoft Office

Videoconferencing

To interact with the World Wide Web, a client computer needs an application layer software package called a: Router package Web browser Web server Uniform Resource Locator package Telnet package

Web browser

Data communications and networking can be considered as a global area of study because: new technologies and applications emerge from a variety of countries and spread around the world the technologies enable global communication the political and regulatory issues are exactly the same in every country a and b none of the above

a and b

Due to advances in high speed communication networks, the information lag, or the time it takes for information to be disseminated around the world, has been significantly shortened. False True

True

When a user accesses an application via a web browser on their mobile device, this is referred to as Internet Explorer BYOD a native app a browser-based approach

a browser-based approach

A local area network is: a network spanning a geographical area that usually encompasses a city or county area (3 to 30 miles). a large central network that connects other networks in a distance spanning exactly 5 miles. a group of personal computers or terminals located in the same general area and connected by a common cable (communication circuit) so they can exchange information such as a set of rooms, a single building, or a set of well-connected buildings. a network spanning a large geographical area (up to 1000s of miles). a network spanning exactly 10 miles with common carrier circuits.

a group of personal computers or terminals located in the same general area and connected by a common cable (communication circuit) so they can exchange information such as a set of rooms, a single building, or a set of well-connected buildings.

Using parity, the probability for detecting an error, given that one has occurred, is: about 0% for either even or odd parity about 70% for even parity and 30% for odd parity about 100% for either even or odd parity about 50% for either even or odd parity about 30% for even parity and 70% for odd parity

about 50% for either even or odd parity

Which of the following is a term used to group together the physical and data link layers? Internetwork layers Hardware layers Application layers Software layers Middleware layers

hardware layers

____________ is one of the most commonly used coding schemes used in data transmission. FDM ASCII ISDN MAU ATM

ASCII

____________ is not a function of a data link protocol. Amplitude shift keying Error control Media access control Message delineation Indicating when a message starts and stops

Amplitude shift keying

A network administrator has received several reports from users of the network that the intranet website on one of company servers is not accessible, but the same users are still able to retrieve their email being stored on the same server. What layer of the Internet model does this problem appear to reside at? transport data link network application physical

application

In which layer of the Internet model would the HTTP protocol be used? physical network data link transport application

application

Which of the following is not a general function by any application program? presentation logic application logic data storage data access logic application access storage

application access storage

Errors on a network can occur: only due to Gaussian noise only on poorly maintained networks only on dial-up type of circuits because of noise on the line only due to lightning strikes

because of noise on the line

In communication protocols, _________ are used to convey the user's meaning. overhead bits information bits start bits flag bits stop bits

information bits

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

intranet

When all bits of a character are transferred one after another, the bits are transferred in ___________ mode. Serial frequency division multiplexing full complex parallel

Serial

A(n) __________ circuit is another name for a multipoint configuration. simplex dedicated analog shared point-to-point

shared

_________ is a special type of one directional; videoconferencing in which content is sent from the server to the user. instant messaging webcasting Net Meeting H.323 broadcasting

webcasting

A coding scheme that uses 10 bits to represent each character is capable of representing _________ different characters. 1024 20 200 512 256

1024

BYOD stands for Bring Your Own Database Build Your Own Device Bring Your Own Device Build Your Own Database

Bring Your Own Device

Which of the following would be a standard or protocol used at the Data Link layer of the Internet or OSI model? TCP Ethernet FTP HTTP IP

Ethernet

The network layer of the Internet model uses the _____________ protocol to route messages though the network. SMTP TCP FTP IP HTTP

IP

__________can obliterate a group of bits, causing a burst error. Impulse noise Attenuation Intermodulation noise White noise Cross-talk

Impulse noise

Which of the following is true with respect to the data link layer? It performs routing functions. It is responsible for encoding the bit-stream as a series of electronic voltages. It organizes data from the physical layer and passes these coherent messages directly to the application layer. It performs error detection. It accepts streams of bits from the application layer.

It performs error detection.

Which of the following is true about the data link protocol, SDLC: It uses a contention media access control protocol and is used in most LANs today. It does not have any error detection capabilities. It transmits each character independently of one another and includes start and stop bits for each character sent. It is a client-server protocol developed by Compaq in 1996. It uses a special bit pattern called a flag at the beginning and end of every frame (or packet).

It uses a special bit pattern called a flag at the beginning and end of every frame (or packet).

The idea for a special hypertext network, called the World Wide Web, was conceived of by: Vinton Cerf, for the U.S. Department of Defense in 1969 as a network of four computers called ARPANET Howard Flieshman of IBM in 1982 as part of the development of the IBM PC Tim Berners-Lee at the European Laboratory for Particle Physics (CERN) in 1989 Microsoft in 1994 as part of the Windows 95 project the University of Minnesota as an extension of Gopher

Tim Berners-Lee at the European Laboratory for Particle Physics (CERN) in 1989

A backbone network is: a network spanning exactly 200 miles with common carrier circuits. a network spanning a large geographical area (up to 1000s of miles). a network spanning a geographical area that usually encompasses a city or county area (3 to 30 miles). a group of personal computers or terminals located in the same general area and connected by a common cable (communication circuit) so they can exchange information. a high speed central network that connects other networks in a distance spanning up to several miles.

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

A(n) __________ is the way in which the functions of the application layer software are spread among the clients and servers in the network. response status architecture application architecture anonymous FTP data access logic fat client

application architecture

In a _________ , more than one data bit is changed by the error-causing condition. data rate shift amplitude key shift Trellis-coded modulation uniform distribution burst error

burst error

Which of the following is not true about a server? stores documents and graphics that can be accessed from any Web browser. can only perform one function on a network. in client/server computing they work together over the network with client computers to support the business application. may be a personal computer or a mainframe on the network. stores data and software that can be accessed by the client.

can only perform one function on a network.

________ is the basic physical layout of the circuit. point-to-point configuration circuit plan circuit design configuration circuit configuration

circuit configuration

What technique is used by most videoconferencing applications to reduce the amount of data being transmitted? authentication encryption hashing identification compression

compression

Which of the following is not a property of a WAN: spans hundreds or thousands of miles connects a group of computers in a small geographic area such as room, floor, building or campus. uses leased lines from IXCs like ATT, MCI, and Sprint provides data transmission speeds from 56Kbps to 10Gbps. connects backbone networks and MANS

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

With the two-tier client-server architecture, the server is responsible for the ________ logic. presentation application physical session data access

data access

Transmission speeds: always have a direct correlation with security are not a factor in selecting a media because all media have more than enough speed to serve current communication demands are a constant, 56Kbps, for all media types differ widely among media are the same among all media

differ widely among media

Asynchronous transmission: uses a continuous series of start bits as an idle signal has a pre-determined, fixed time between sending characters each character is transmitted independently of all other characters is typically used on multipoint half duplex circuits is used to transmit each character simultaneously with all other characters

each character is transmitted independently of all other characters

Which of the following is the most secure wired media? unshielded twisted pair fiber optic cable shielded twisted pair coaxial cable infrared

fiber optic cable

Which of the following media is least susceptible to noise? shielded twisted pair coaxial cable fiber optic cable twisted pair unshielded twisted pair

fiber optic cable

The ability to transmit in both directions, but only in one direction at a time is an example of _______________ transmission. digital half-duplex simplex full-duplex analog

half-duplex

Media access control: is not very important in point-to-point with full duplex configuration is not very important in a multipoint configuration is not very important in a point-to-point with a half duplex configuration is not very important in local area networks does not control when computers transmit

is not very important in point-to-point with full duplex configuration

In a two-tier client-server architecture, a client computer needs to use an application layer software package called a ________________ to send e-mail: mail user agent router agent gateway agent Webcast package message transfer agent

mail user agent

A MOOC is an example of a(n) native app BYOD massively online technology browser-based technology

massively online technology

Which of the following is true about the data link protocol, Ethernet (IEEE 802.3)? it is a bit-oriented protocol it is not very popular it uses block check characters for error detection it uses parity bits for error detection newer version permits jumbo frames

newer version permits jumbo frames

IMAP (Internet Message Access Protocol): is exactly the same as SMTP permits an e-mail message to remain stored on the mail server even after they have been read by a client computer is a set of standards that define how email is to be processed between mail servers is exactly the same as POP copies an e-mail message from the client computer's hard disk, deletes it from the client, and stores it on the mail server

permits an e-mail message to remain stored on the mail server even after they have been read by a client computer

Which is not true about point-to-point circuits? point-to-point circuits are dedicated to the use of the two computers. point-to-point circuits are used when the computers generate enough traffic to fill the capacity of the communication circuit. point-to-point circuits reduce the amount of cable required and use the circuit more efficiently than multipoint circuits. point-to-point circuits are called dedicated circuits. point-to-point circuits are more expensive than multipoint circuits.

point-to-point circuits reduce the amount of cable required and use the circuit more efficiently than multipoint circuits.

Which of the following is not an important factor to consider when selecting media to be used in a network? cost transmission distance security prestige value of the type of media type of network

prestige value of the type of media

Which is not a function of the physical layer: specifying the type of connection and type of signals, waves or pulses that pass through it. providing the physical connection between sender and receiver. transmission of bits. providing error-free transmission of data. defining the rules by which one and zeroes are transmitted.

providing error-free transmission of data.

There are required and optional parts of an HTTP response. They are: response status, response header, response body response address, response header, response body response status, response body response status, response header response address, response header

response status, response header, response body

_____________ is not a form of modulation used to transform digital data into analog signals. amplitude shift keying phase modulation frequency modulation synchronous time division amplitude modulation

synchronous time division

Another term for impulse noise is: Gaussian noise cross-talk intermodulation noise attenuation spikes

spikes

The function of the file server is to : store HTML documents for an Internet or intranet web site. manage all printing requests from clients on the network. transfer e-mail messages to other servers on the network. coordinate the communication of client and servers on the network. store data and software programs that can be used by client computers on the network.

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

One underlying problem with a host-based network is that: clients (terminals) do not require sophisticated hardware/software because they do not perform most of the work in this type of architecture there are economies of scale because all computer resources are centralized the architecture is relatively simple and works well the server can get overloaded since it must process all messages the server is the one point of control which simplifies security

the server can get overloaded since it must process all messages

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? session presentation physical transport application

transport

In general, controlled approaches: work better than contention approaches for small networks that have low usage have many collisions work better than contention approaches for all sizes of networks work better than contention approaches for large networks that have high usage do not require a host, server, or active monitor to assign media access control

work better than contention approaches for large networks that have high usage