cost 4325 HW I

Time division multiplexing is more efficient that frequency division multiplexing because the guardbands used in the frequency division multiplexing or not needed.

True

Token passing is a term that refers to hub polling, in which one computer starts a poll and passes it to the next computer on a multipoint circuit.

True

WDM is a version of FDM used in fiber-optic cables.

True

With roll-call polling, a server polls clients in a consecutive, pre-arranged priority list.

True

Your typical web browsing scenario where a person using a web browser accesses a web page from a server on the Internet is a good example of a client-server application architecture.

True

With a client-based network, one fundamental problem is that:

all data on the server must travel to the client for processing

A(n) __________ is the way in which the functions of the application layer software are spread among the clients and servers in the network.

application architecture

________ is the presentation of information to the user and the acceptance of the user's commands.

presentation logic

Which department of Next Day Air Service Inc (the case study) has no automation whatsoever? 1. Sales and Marketing 2. Accounts Payable 3. Accounts Receivable 4. Fleet Maintenance Division 5. Information Services

4. fleet maintenance division

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

4. intranet

The _________ layer is responsible for routing of messages from the sender to the final destination. data communication layer resident layer application layer network layer physical layer

4. network layer

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

5. request line, request header, request body

Contention MAC approaches work better in a large network with high usage.

False

Data transmission errors are typically uniformly distributed in time.

False

Digital transmission produces more errors than analog transmission.

False

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 lengthened.

False

Ethernet is an example of a network layer protocol.

False

Fiber optic cable carries signals in traditional electrical form.

False

Frequency modulation refers to the changing of the height of the sound wave.

False

Guided media refers to the type of media in which the message is broadcast through the air.

False

Host-based and client-based networks are similar in that the client computer performs most of the work.

False

Impulse noise is caused by the thermal agitation of electrons.

False

In simplex transmission, the data flows in both directions at the same time

False

Nonreturn to zero is a type of unipolar signaling

False

Only the sender of a data transmission needs to be concerned about the rules or protocols that govern how it communicates with the receiver.

False

Propagation delay is negligible with satellite transmission.

False

Symbol rate is the number of bits transmitted per second.

False

The OSI model is currently the most widely implemented network model used to develop and build networks of any size, including the Internet itself.

False

The Simple Mail Transfer Protocol is the least commonly used e-mail standard.

False

The application layer is the seventh layer of the Internet model and specifies the type of connection and the electrical signals that pass through it.

False

The standard protocol for communication between a Web browser and a Web server is the web protocol.

False

Using the POP standard for client to server e-mail communication, the e-mail messages remain on the server computer.

False

With modem communications, the receiving modem converts the incoming digital signal from the telephone line into an analog signal that can be understood by the computer.

False

A car manufacturer may give access to certain portions of its network to some of its suppliers via the Internet. This is an example of an extranet.

True

A walkie-talkie is an example of half-duplex transmission.

True

At the transport layer in the Internet model, TCP is responsible for breaking large files received from the application layer into smaller messages and opening a connection to a server for transferring them.

True

Attenuation refers to the loss of signal strength

True

Attenuation refers to the loss of signal strength.

True

Coding schemes are groups of bits that translate into the "alphabet" of any given system.

True

Contention is commonly used with Ethernet local area networks.

True

Data communication standards enable each layer in the sending computer to communicate with its corresponding layer in the receiving computer.

True

Data compression can increase the throughput of a communication link.

True

Ethernet, a common LAN technology, uses Manchester encoding.

True

If a computer transmits a message containing "ABC" and the destination computer receives "abc" as the message, the message is corrupted.

True

In a client-server network, the presentation logic is the responsibility of the client computer.

True

In full-duplex transmission, two stations can send and receive simultaneously.

True

The data link layer accepts messages from the network layer and controls the hardware that transmits them.

True

The four general functions of any application program are: data storage, data access logic, application logic and presentation logic.

True

Which of the following is not a key advantage of digital transmission? It permits only low transmission rates. It is more efficient. It is simpler to integrate voice, video, and data on the same circuit. It is more secure. It produces fewer errors.

1. It permits only low transmission rates.

A backbone network is: a high speed central network that connects other networks in a distance spanning up to several 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 network spanning a geographical area that usually encompasses a city or county area (3 to 30 miles). a network spanning a large geographical area (up to 1000s of miles). a network spanning exactly 200 miles with common carrier circuits.

1. a high speed

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

1. burst error

With contention: computers wait until the circuit is free before they send data the server or front end processor works consecutively through a list of clients to determine who should have access to the media the front end processor must wait for a response from the polled client or terminal one computer starts the poll and passes it to the next computer on the multipoint circuit there is never a chance for "collision," or two computers trying to send data at the same time

1. computers

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

1. fiber optic cable

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

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

Cross-talk: occurs when one circuit picks up signals in another is always bothersome because it has a high signal strength decreases with increased proximity of two wires decreases during wet or damp weather increases with lower frequency signals

1. occurs when one

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 address, response header response status, response header

1. response status, response header, response body

_____________ is an effective way to prevent impulse noise, cross talk, and intermodulation noise. Shielding wires Adding fluorescent lights Adding repeaters to a circuit Adding amplifiers to a circuit Shorting a circuit

1. shielding wires

A local area network is: 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 geographical area that usually encompasses a city or county area (3 to 30 miles). a network spanning a large geographical area (up to 1000s of miles). a network spanning exactly 10 miles with common carrier circuits.

2. a group of personal

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

2. because of

When a signal is reflected back to the transmitting equipment, it is called a(n) _________. white noise echo crosstalk attenuation impulse noise

2. echo

The primary reason for networking standards is to: simplify cost accounting for networks ensure that hardware and software produced by different vendors can work together make it more difficult to develop hardware and software that link different networks ensure that all network components of a particular network can be provided by only one vendor lock customers into buying network components from one vendor

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

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

2. hardware layers

In the Internet model, the application layer corresponds to the ________ layer(s) of the OSI model. data link and network session, presentation and application application layer application and presentation network, transport and presentation

2. session, presentation and application

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? presentation transport physical session application

2. transport

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

3. amplitude shift

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. WAN BN extranet intranet MAN

3. extranet

A "thick client" architecture approach: always is a two-tier network architecture always is an n-tiered architecture places all or almost all of the application logic on the client places all or almost all of the application logic on the server refers to the size of the cable connecting the clients to the network

3. places all or almost all of the application logic on the client

The _________ layer performs error checking which is redundant to some extent with the function of the _________ layer. application, presentation physical, data link transport, data link presentation, transport network, physical

3. presentation, transportation

The primary source of error in data communications is: echoes intermodulation noise spikes attenuation cross-talk

3. spikes

How are the application architecture functions split up in a client-server network? the presentation logic and data storage are on the client, while the data access logic is on the server the data storage, data access, and presentation logic are on the client the presentation logic is on the client, while the data storage and data access logic are on the server the data storage and data access logic are on the client, while the presentation logic are on the server the presentation logic and data access logic are on the client, and the data storage is on the server

3. the presentation logic is on the client, while the data storage and data access logic are on the server

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

4. a and b

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

4. connects a group

Two fundamentally different types of data are: DSL and ADSL asymmetric and symmetric Microsoft and IBM digital and analog local area and wide area

4. digital

A "thin client" approach places most of the application logic on the client.

False

A local area network (LAN) connects other LANs and backbone networks (BNs) located in different areas to each other and to wide area networks in a span from 3 to 30 miles.

False

In the three-tier architecture, the software on the client computer is responsible for the presentation logic, an application server is responsible for the application logic and a separate database server is responsible for the data access logic and data storage.

True

Microwave transmissions require a line of sight between any two points.

True

Middleware is a software that can translate between software from different vendors.

True

Scalability refers to the ability to increase or decrease the capacity of the computing infrastructure in response to changing capacity needs.

True

With the two-tier client-server architecture, only the server is responsible for the ________ logic.

data access logic

One underlying problem with a host-based network is that:

the server can get overloaded since it must process all messages